International Journal of Molecular Sciences

Editorial

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145 KiB

Open AccessEditorial

Regulation of Plant Mineral Nutrition: Transport, Sensing and Signaling

by Hatem Rouached and Lam-Son Phan Tran

Int. J. Mol. Sci. 2015, 16(12), 29717-29719; https://doi.org/10.3390/ijms161226198 - 11 Dec 2015

Cited by 7 | Viewed by 5356

Abstract

Limitation in crop yield productivity significantly contributes to the pressing problem of food security and malnutrition worldwide. [...] Full article

(This article belongs to the Special Issue Regulation of Plant Mineral Nutrition: Transport, Sensing and Signalling)

626 KiB

Open AccessEditorial

Symbiotic Nitrogen Fixation in Legume Nodules: Metabolism and Regulatory Mechanisms

by Saad Sulieman and Lam-Son Phan Tran

Int. J. Mol. Sci. 2014, 15(11), 19389-19393; https://doi.org/10.3390/ijms151119389 - 24 Oct 2014

Cited by 27 | Viewed by 7172

Abstract

The special issue “Symbiotic Nitrogen Fixation in Legume Nodules: Metabolism and Regulatory Mechanisms” aims to investigate the physiological and biochemical advances in the symbiotic process with an emphasis on nodule establishment, development and functioning. The original research articles included in this issue provide [...] Read more.

The special issue “Symbiotic Nitrogen Fixation in Legume Nodules: Metabolism and Regulatory Mechanisms” aims to investigate the physiological and biochemical advances in the symbiotic process with an emphasis on nodule establishment, development and functioning. The original research articles included in this issue provide important information regarding novel aspects of nodule metabolism and various regulatory pathways, which could have important future implications. This issue also included one review article that highlights the importance of using legume trees in the production of renewable biofuels. Full article

(This article belongs to the Special Issue Symbiotic Nitrogen Fixation in Legume Nodules: Metabolism and Regulatory Mechanisms)

169 KiB

Open AccessEditorial

Plant Neurobiology, a Fascinating Perspective in the Field of Research on Plant Secondary Metabolites

by Marcello Iriti

Int. J. Mol. Sci. 2013, 14(6), 10819-10821; https://doi.org/10.3390/ijms140610819 - 23 May 2013

Cited by 21 | Viewed by 8104

Abstract

In this Editorial, I comment on the exciting and original topic of plant neurobiology, focusing on natural products whose biosynthesis is shared by animal and plant organisms, i.e., indoleamines (melatonin and serotonin) and catecholamines (dopamine, norepinephrine and epinephrine). Full article

(This article belongs to the Special Issue Molecular Research in Plant Secondary Metabolism)

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Research

Jump to: Editorial, Review, Other

1850 KiB

Open AccessArticle

Comparative Metabolite Profiling of Triterpenoid Saponins and Flavonoids in Flower Color Mutations of Primula veris L.

by Lysanne Apel, Dietmar R. Kammerer, Florian C. Stintzing and Otmar Spring

Int. J. Mol. Sci. 2017, 18(1), 153; https://doi.org/10.3390/ijms18010153 - 13 Jan 2017

Cited by 34 | Viewed by 10149

Abstract

Primula veris L. is an important medicinal plant with documented use for the treatment of gout, headache and migraine reaching back to the Middle Ages. Triterpenoid saponins from roots and flowers are used in up-to-date phytotherapeutic treatment of bronchitis and colds due to [...] Read more.

Primula veris L. is an important medicinal plant with documented use for the treatment of gout, headache and migraine reaching back to the Middle Ages. Triterpenoid saponins from roots and flowers are used in up-to-date phytotherapeutic treatment of bronchitis and colds due to their expectorant and secretolytic effects. In addition to the wild type plants with yellow petals, a red variant and an intermediate orange form of Primula veris L. have recently been found in a natural habitat. The secondary metabolite profiles of roots, leaves and flowers of these rare variants were investigated and compared with the wild type metabolome. Two flavonoids, six flavonoid glycosides, four novel methylated flavonoid glycosides, five anthocyanins and three triterpenoid saponins were identified in alcoholic extracts from the petals, leaves and roots of the three variants by high performance liquid chromatography (HPLC)-diode array detection (DAD)/mass spectrometry (MSⁿ) analyses. Anthocyanins were detected in the petals of the red and orange variety, but not in the wild type. No other effects on the metabolite profiles of the three varieties have been observed. The possibility is discussed that a regulatory step of the anthocyanin biosynthetic pathway may have been affected by mutation thus triggering color polymorphism in the petals. Full article

(This article belongs to the Special Issue Metabolomics in the Plant Sciences)

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1531 KiB

Open AccessCommunication

Plant-to-Plant Variability in Root Metabolite Profiles of 19 Arabidopsis thaliana Accessions Is Substance-Class-Dependent

by Susann Mönchgesang, Nadine Strehmel, Diana Trutschel, Lore Westphal, Steffen Neumann and Dierk Scheel

Int. J. Mol. Sci. 2016, 17(9), 1565; https://doi.org/10.3390/ijms17091565 - 16 Sep 2016

Cited by 20 | Viewed by 6448

Abstract

Natural variation of secondary metabolism between different accessions of Arabidopsis thaliana (A. thaliana) has been studied extensively. In this study, we extended the natural variation approach by including biological variability (plant-to-plant variability) and analysed root metabolic patterns as well as their [...] Read more.

Natural variation of secondary metabolism between different accessions of Arabidopsis thaliana (A. thaliana) has been studied extensively. In this study, we extended the natural variation approach by including biological variability (plant-to-plant variability) and analysed root metabolic patterns as well as their variability between plants and naturally occurring accessions. To screen 19 accessions of A. thaliana, comprehensive non-targeted metabolite profiling of single plant root extracts was performed using ultra performance liquid chromatography/electrospray ionization quadrupole time-of-flight mass spectrometry (UPLC/ESI-QTOF-MS) and gas chromatography/electron ionization quadrupole mass spectrometry (GC/EI-QMS). Linear mixed models were applied to dissect the total observed variance. All metabolic profiles pointed towards a larger plant-to-plant variability than natural variation between accessions and variance of experimental batches. Ratios of plant-to-plant to total variability were high and distinct for certain secondary metabolites. None of the investigated accessions displayed a specifically high or low biological variability for these substance classes. This study provides recommendations for future natural variation analyses of glucosinolates, flavonoids, and phenylpropanoids and also reference data for additional substance classes. Full article

(This article belongs to the Special Issue Metabolomics in the Plant Sciences)

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2245 KiB

Open AccessArticle

Cannibalism Affects Core Metabolic Processes in Helicoverpa armigera Larvae—A 2D NMR Metabolomics Study

by Fredd Vergara, Amiu Shino and Jun Kikuchi

Int. J. Mol. Sci. 2016, 17(9), 1470; https://doi.org/10.3390/ijms17091470 - 2 Sep 2016

Cited by 8 | Viewed by 5705

Abstract

Cannibalism is known in many insect species, yet its impact on insect metabolism has not been investigated in detail. This study assessed the effects of cannibalism on the metabolism of fourth-instar larvae of the non-predatory insect Helicoverpa armigera (Lepidotera: Noctuidea). Two groups of [...] Read more.

Cannibalism is known in many insect species, yet its impact on insect metabolism has not been investigated in detail. This study assessed the effects of cannibalism on the metabolism of fourth-instar larvae of the non-predatory insect Helicoverpa armigera (Lepidotera: Noctuidea). Two groups of larvae were analyzed: one group fed with fourth-instar larvae of H. armigera (cannibal), the other group fed with an artificial plant diet. Water-soluble small organic compounds present in the larvae were analyzed using two-dimensional nuclear magnetic resonance (NMR) and principal component analysis (PCA). Cannibalism negatively affected larval growth. PCA of NMR spectra showed that the metabolic profiles of cannibal and herbivore larvae were statistically different with monomeric sugars, fatty acid- and amino acid-related metabolites as the most variable compounds. Quantitation of ¹H-¹³C HSQC (Heteronuclear Single Quantum Coherence) signals revealed that the concentrations of glucose, glucono-1,5-lactone, glycerol phosphate, glutamine, glycine, leucine, isoleucine, lysine, ornithine, proline, threonine and valine were higher in the herbivore larvae. Full article

(This article belongs to the Special Issue Metabolomics in the Plant Sciences)

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Open AccessArticle

Piriformospora indica Stimulates Root Metabolism of Arabidopsis thaliana

by Nadine Strehmel, Susann Mönchgesang, Siska Herklotz, Sylvia Krüger, Jörg Ziegler and Dierk Scheel

Int. J. Mol. Sci. 2016, 17(7), 1091; https://doi.org/10.3390/ijms17071091 - 8 Jul 2016

Cited by 34 | Viewed by 11437

Abstract

Piriformospora indica is a root-colonizing fungus, which interacts with a variety of plants including Arabidopsis thaliana. This interaction has been considered as mutualistic leading to growth promotion of the host. So far, only indolic glucosinolates and phytohormones have been identified as key [...] Read more.

Piriformospora indica is a root-colonizing fungus, which interacts with a variety of plants including Arabidopsis thaliana. This interaction has been considered as mutualistic leading to growth promotion of the host. So far, only indolic glucosinolates and phytohormones have been identified as key players. In a comprehensive non-targeted metabolite profiling study, we analyzed Arabidopsis thaliana’s roots, root exudates, and leaves of inoculated and non-inoculated plants by ultra performance liquid chromatography/electrospray ionization quadrupole-time-of-flight mass spectrometry (UPLC/(ESI)-QTOFMS) and gas chromatography/electron ionization quadrupole mass spectrometry (GC/EI-QMS), and identified further biomarkers. Among them, the concentration of nucleosides, dipeptides, oligolignols, and glucosinolate degradation products was affected in the exudates. In the root profiles, nearly all metabolite levels increased upon co-cultivation, like carbohydrates, organic acids, amino acids, glucosinolates, oligolignols, and flavonoids. In the leaf profiles, we detected by far less significant changes. We only observed an increased concentration of organic acids, carbohydrates, ascorbate, glucosinolates and hydroxycinnamic acids, and a decreased concentration of nitrogen-rich amino acids in inoculated plants. These findings contribute to the understanding of symbiotic interactions between plant roots and fungi of the order of Sebacinales and are a valid source for follow-up mechanistic studies, because these symbioses are particular and clearly different from interactions of roots with mycorrhizal fungi or dark septate endophytes Full article

(This article belongs to the Special Issue Metabolomics in the Plant Sciences)

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Open AccessArticle

Stable Isotope-Assisted Evaluation of Different Extraction Solvents for Untargeted Metabolomics of Plants

by Maria Doppler, Bernhard Kluger, Christoph Bueschl, Christina Schneider, Rudolf Krska, Sylvie Delcambre, Karsten Hiller, Marc Lemmens and Rainer Schuhmacher

Int. J. Mol. Sci. 2016, 17(7), 1017; https://doi.org/10.3390/ijms17071017 - 28 Jun 2016

Cited by 71 | Viewed by 8355

Abstract

The evaluation of extraction protocols for untargeted metabolomics approaches is still difficult. We have applied a novel stable isotope-assisted workflow for untargeted LC-HRMS-based plant metabolomics , which allows for the first time every detected feature to be considered for method evaluation. The efficiency [...] Read more.

The evaluation of extraction protocols for untargeted metabolomics approaches is still difficult. We have applied a novel stable isotope-assisted workflow for untargeted LC-HRMS-based plant metabolomics , which allows for the first time every detected feature to be considered for method evaluation. The efficiency and complementarity of commonly used extraction solvents, namely 1 + 3 (v/v) mixtures of water and selected organic solvents (methanol, acetonitrile or methanol/acetonitrile 1 + 1 (v/v)), with and without the addition of 0.1% (v/v) formic acid were compared. Four different wheat organs were sampled, extracted and analysed by LC-HRMS. Data evaluation was performed with the in-house-developed MetExtract II software and R. With all tested solvents a total of 871 metabolites were extracted in ear, 785 in stem, 733 in leaf and 517 in root samples, respectively. Between 48% (stem) and 57% (ear) of the metabolites detected in a particular organ were found with all extraction mixtures, and 127 of 996 metabolites were consistently shared between all extraction agent/organ combinations. In aqueous methanol, acidification with formic acid led to pronounced pH dependency regarding the precision of metabolite abundance and the number of detectable metabolites, whereas extracts of acetonitrile-containing mixtures were less affected. Moreover, methanol and acetonitrile have been found to be complementary with respect to extraction efficiency. Interestingly, the beneficial properties of both solvents can be combined by the use of a water-methanol-acetonitrile mixture for global metabolite extraction instead of aqueous methanol or aqueous acetonitrile alone. Full article

(This article belongs to the Special Issue Metabolomics in the Plant Sciences)

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Open AccessArticle

Metabolic Responses of Poplar to Apripona germari (Hope) as Revealed by Metabolite Profiling

by Lijuan Wang, Liangjian Qu, Liwei Zhang, Jianjun Hu, Fang Tang and Mengzhu Lu

Int. J. Mol. Sci. 2016, 17(6), 923; https://doi.org/10.3390/ijms17060923 - 20 Jun 2016

Cited by 14 | Viewed by 6366

Abstract

Plants have developed biochemical responses to adapt to biotic stress. To characterize the resistance mechanisms in poplar tree against Apripona germari, comprehensive metabolomic changes of poplar bark and xylem in response to A. germari infection were examined by gas chromatography time-of-flight mass [...] Read more.

Plants have developed biochemical responses to adapt to biotic stress. To characterize the resistance mechanisms in poplar tree against Apripona germari, comprehensive metabolomic changes of poplar bark and xylem in response to A. germari infection were examined by gas chromatography time-of-flight mass spectrometry (GC–TOF/MS). It was found that, four days after feeding (stage I), A. germari infection brought about changes in various metabolites, such as phenolics, amino acids and sugars in both bark and xylem. Quinic acid, epicatechin, epigallocatechin and salicin might play a role in resistance response in bark, while coniferyl alcohol, ferulic acid and salicin contribute resistance in xylem. At feeding stages II when the larvae fed for more than one month, fewer defensive metabolites were induced, but levels of many intermediates of glycolysis and the tricarboxylic acid (TCA) cycle were reduced, especially in xylem. These results suggested that the defense strategies against A. germari might depend mainly on the early defense responses in poplar. In addition, it was found that bark and xylem in infected trees accumulated higher levels of salicylic acid and 4-aminobutyric acid, respectively, these tissues displaying a direct and systemic reaction against A. germari. However, the actual role of the two metabolites in A. germari-induced defense in poplar requires further investigation. Full article

(This article belongs to the Special Issue Metabolomics in the Plant Sciences)

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Open AccessArticle

Metabolic Fingerprinting to Assess the Impact of Salinity on Carotenoid Content in Developing Tomato Fruits

by Lieven Van Meulebroek, Jochen Hanssens, Kathy Steppe and Lynn Vanhaecke

Int. J. Mol. Sci. 2016, 17(6), 821; https://doi.org/10.3390/ijms17060821 - 26 May 2016

Cited by 12 | Viewed by 7576

Abstract

As the presence of health-promoting substances has become a significant aspect of tomato fruit appreciation, this study investigated nutrient solution salinity as a tool to enhance carotenoid accumulation in cherry tomato fruit (Solanum lycopersicum L. cv. Juanita). Hereby, a key objective was [...] Read more.

As the presence of health-promoting substances has become a significant aspect of tomato fruit appreciation, this study investigated nutrient solution salinity as a tool to enhance carotenoid accumulation in cherry tomato fruit (Solanum lycopersicum L. cv. Juanita). Hereby, a key objective was to uncover the underlying mechanisms of carotenoid metabolism, moving away from typical black box research strategies. To this end, a greenhouse experiment with five salinity treatments (ranging from 2.0 to 5.0 decisiemens (dS) m⁻¹) was carried out and a metabolomic fingerprinting approach was applied to obtain valuable insights on the complicated interactions between salinity treatments, environmental conditions, and the plant’s genetic background. Hereby, several hundreds of metabolites were attributed a role in the plant’s salinity response (at the fruit level), whereby the overall impact turned out to be highly depending on the developmental stage. In addition, 46 of these metabolites embraced a dual significance as they were ascribed a prominent role in carotenoid metabolism as well. Based on the specific mediating actions of the retained metabolites, it could be determined that altered salinity had only marginal potential to enhance carotenoid accumulation in the concerned tomato fruit cultivar. This study invigorates the usefulness of metabolomics in modern agriculture, for instance in modeling tomato fruit quality. Moreover, the metabolome changes that were caused by the different salinity levels may enclose valuable information towards other salinity-related plant processes as well. Full article

(This article belongs to the Special Issue Metabolomics in the Plant Sciences)

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1439 KiB

Open AccessArticle

Analysis of 2-(2-Phenylethyl)chromones by UPLC-ESI-QTOF-MS and Multivariate Statistical Methods in Wild and Cultivated Agarwood

by Yuanbin Li, Nan Sheng, Lingli Wang, Shijie Li, Jiannan Chen and Xiaoping Lai

Int. J. Mol. Sci. 2016, 17(5), 771; https://doi.org/10.3390/ijms17050771 - 23 May 2016

Cited by 31 | Viewed by 6853

Abstract

Agarwood is the fragrant resinous material mainly formed from species of Aquilaria. 2-(2-phenylethyl)chromones, especially the highly oxidized 5,6,7,8-tetrahydro-2-(2-phenylethyl)chromones, are the main representative compounds from agarwood. It is important to determine whether agarwood in trade is from cultivated trees or natural trees in [...] Read more.

Agarwood is the fragrant resinous material mainly formed from species of Aquilaria. 2-(2-phenylethyl)chromones, especially the highly oxidized 5,6,7,8-tetrahydro-2-(2-phenylethyl)chromones, are the main representative compounds from agarwood. It is important to determine whether agarwood in trade is from cultivated trees or natural trees in the Convention on the International Trade in Endangered Species (CITES). We characterized the 2-(2-phenylethyl)chromones in agarwood by ultra-performance liquid chromatography coupled with electrospray ionization mass spectrometry (UPLC–ESI-QTOF-MS) and differentiated wild from cultivated agarwood by metabolomic analysis. A total of 141 chromones including 50 potentially new compounds were evaluated as belonging to four structural classes (unoxidized 2-(2-phenylethyl)chromones, 5,6,7,8-tetrahydro-2-(2-phenylethyl)-chromones, bi-2-(2-phenylethyl)chromones, and tri-2-(2-phenylethyl)chromones). The metabolic difference between wild and cultivated agarwood was analyzed by component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA). Fourteen markers of metabolisms in wild and cultivated agarwood were constructed (e.g., 6,7-dimethoxy-2-(2-phenylethyl)chromone, 6,8-dihydroxy-2-(2-phenylethyl)chromone, 6-methoxy-2-(2-phenylethyl)chromone, etc.). These results indicated that UPLC–ESI-QTOF-MS-based metabonomics analysis in agarwood may be useful for distinguishing wild agarwood from cultivated agarwood. Full article

(This article belongs to the Special Issue Metabolomics in the Plant Sciences)

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Open AccessArticle

Overexpression of the Transcription Factors GmSHN1 and GmSHN9 Differentially Regulates Wax and Cutin Biosynthesis, Alters Cuticle Properties, and Changes Leaf Phenotypes in Arabidopsis

by Yangyang Xu, Hanying Wu, Mingming Zhao, Wang Wu, Yinong Xu and Dan Gu

Int. J. Mol. Sci. 2016, 17(4), 587; https://doi.org/10.3390/ijms17040587 - 21 Apr 2016

Cited by 26 | Viewed by 7968

Abstract

SHINE (SHN/WIN) clade proteins, transcription factors of the plant-specific APETALA 2/ethylene-responsive element binding factor (AP2/ERF) family, have been proven to be involved in wax and cutin biosynthesis. Glycine max is an important economic crop, but its molecular mechanism of wax biosynthesis is rarely [...] Read more.

SHINE (SHN/WIN) clade proteins, transcription factors of the plant-specific APETALA 2/ethylene-responsive element binding factor (AP2/ERF) family, have been proven to be involved in wax and cutin biosynthesis. Glycine max is an important economic crop, but its molecular mechanism of wax biosynthesis is rarely characterized. In this study, 10 homologs of Arabidopsis SHN genes were identified from soybean. These homologs were different in gene structures and organ expression patterns. Constitutive expression of each of the soybean SHN genes in Arabidopsis led to different leaf phenotypes, as well as different levels of glossiness on leaf surfaces. Overexpression of GmSHN1 and GmSHN9 in Arabidopsis exhibited 7.8-fold and 9.9-fold up-regulation of leaf cuticle wax productions, respectively. C31 and C29 alkanes contributed most to the increased wax contents. Total cutin contents of leaves were increased 11.4-fold in GmSHN1 overexpressors and 5.7-fold in GmSHN9 overexpressors, mainly through increasing C16:0 di-OH and dioic acids. GmSHN1 and GmSHN9 also altered leaf cuticle membrane ultrastructure and increased water loss rate in transgenic Arabidopsis plants. Transcript levels of many wax and cutin biosynthesis and leaf development related genes were altered in GmSHN1 and GmSHN9 overexpressors. Overall, these results suggest that GmSHN1 and GmSHN9 may differentially regulate the leaf development process as well as wax and cutin biosynthesis. Full article

(This article belongs to the Special Issue Molecular Research in Plant Secondary Metabolism 2015)

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Open AccessArticle

Environmental Conditions Influence Induction of Key ABC-Transporter Genes Affecting Glyphosate Resistance Mechanism in Conyza canadensis

by Eleni Tani, Demosthenis Chachalis, Ilias S. Travlos and Dimitrios Bilalis

Int. J. Mol. Sci. 2016, 17(4), 342; https://doi.org/10.3390/ijms17040342 - 20 Apr 2016

Cited by 22 | Viewed by 6068

Abstract

Conyza canadensis has been reported to be the most frequent weed species that evolved resistance to glyphosate in various parts of the world. The objective of the present study was to investigate the effect of environmental conditions (temperature and light) on the expression [...] Read more.

Conyza canadensis has been reported to be the most frequent weed species that evolved resistance to glyphosate in various parts of the world. The objective of the present study was to investigate the effect of environmental conditions (temperature and light) on the expression levels of the EPSPS gene and two major ABC-transporter genes (M10 and M11) on glyphosate susceptible (GS) and glyphosate resistant (GR) horseweed populations, collected from several regions across Greece. Real-time PCR was conducted to determine the expression level of the aforementioned genes when glyphosate was applied at normal (1×; 533 g·a.e.·ha⁻¹) and high rates (4×, 8×), measured at an early one day after treatment (DAT) and a later stage (four DAT) of expression. Plants were exposed to light or dark conditions, at three temperature regimes (8, 25, 35 °C). GR plants were made sensitive when exposed to 8 °C with light; those sensitized plants behaved biochemically (shikimate accumulation) and molecularly (expression of EPSPS and ABC-genes) like the GS plants. Results from the current study show the direct link between the environmental conditions and the induction level of the above key genes that likely affect the efficiency of the proposed mechanism of glyphosate resistance. Full article

(This article belongs to the Special Issue Effects of Herbicides and Heavy Metals to the Structure and Function of Plant Cells)

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Open AccessArticle

Physical Characteristics of the Leaves and Latex of Papaya Plants Infected with the Papaya meleira Virus

by Anuar Magaña-Álvarez, Jean Carlos Vencioneck Dutra, Tarcio Carneiro, Daisy Pérez-Brito, Raúl Tapia-Tussell, Jose Aires Ventura, Inocencio Higuera-Ciapara, Patricia Machado Bueno Fernandes and Antonio Alberto Ribeiro Fernandes

Int. J. Mol. Sci. 2016, 17(4), 574; https://doi.org/10.3390/ijms17040574 - 15 Apr 2016

Cited by 4 | Viewed by 6281

Abstract

Sticky disease, which is caused by Papaya meleira virus (PMeV), is a significant papaya disease in Brazil and Mexico, where it has caused severe economic losses, and it seems to have spread to Central and South America. Studies assessing the pathogen-host interaction at [...] Read more.

Sticky disease, which is caused by Papaya meleira virus (PMeV), is a significant papaya disease in Brazil and Mexico, where it has caused severe economic losses, and it seems to have spread to Central and South America. Studies assessing the pathogen-host interaction at the nano-histological level are needed to better understand the mechanisms that underlie natural resistance. In this study, the topography and mechanical properties of the leaf midribs and latex of healthy and PMeV-infected papaya plants were observed by atomic force microscopy and scanning electron microscopy. Healthy plants displayed a smooth surface with practically no roughness of the leaf midribs and the latex and a higher adhesion force than infected plants. PMeV promotes changes in the leaf midribs and latex, making them more fragile and susceptible to breakage. These changes, which are associated with increased water uptake and internal pressure in laticifers, causes cell disruption that leads to spontaneous exudation of the latex and facilitates the spread of PMeV to other laticifers. These results provide new insights into the papaya-PMeV interaction that could be helpful for controlling papaya sticky disease. Full article

(This article belongs to the Special Issue Plant Molecular Biology)

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Open AccessArticle

Comparative Small RNA Analysis of Pollen Development in Autotetraploid and Diploid Rice

by Xiang Li, Muhammad Qasim Shahid, Jinwen Wu, Lan Wang, Xiangdong Liu and Yonggen Lu

Int. J. Mol. Sci. 2016, 17(4), 499; https://doi.org/10.3390/ijms17040499 - 12 Apr 2016

Cited by 95 | Viewed by 9690

Abstract

MicroRNAs (miRNAs) play key roles in plant reproduction. However, knowledge on microRNAome analysis in autotetraploid rice is rather limited. Here, high-throughput sequencing technology was employed to analyze miRNAomes during pollen development in diploid and polyploid rice. A total of 172 differentially expressed miRNAs [...] Read more.

MicroRNAs (miRNAs) play key roles in plant reproduction. However, knowledge on microRNAome analysis in autotetraploid rice is rather limited. Here, high-throughput sequencing technology was employed to analyze miRNAomes during pollen development in diploid and polyploid rice. A total of 172 differentially expressed miRNAs (DEM) were detected in autotetraploid rice compared to its diploid counterpart, and 57 miRNAs were specifically expressed in autotetraploid rice. Of the 172 DEM, 115 and 61 miRNAs exhibited up- and down-regulation, respectively. Gene Ontology analysis on the targets of up-regulated DEM showed that they were enriched in transport and membrane in pre-meiotic interphase, reproduction in meiosis, and nucleotide binding in single microspore stage. osa-miR5788 and osa-miR1432-5p_R+1 were up-regulated in meiosis and their targets revealed interaction with the meiosis-related genes, suggesting that they may involve in the genes regulation associated with the chromosome behavior. Abundant 24 nt siRNAs associated with transposable elements were found in autotetraploid rice during pollen development; however, they significantly declined in diploid rice, suggesting that 24 nt siRNAs may play a role in pollen development. These findings provide a foundation for understanding the effect of polyploidy on small RNA expression patterns during pollen development that cause pollen sterility in autotetraploid rice. Full article

(This article belongs to the Special Issue Plant Molecular Biology)

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Open AccessArticle

Expression of Castor LPAT2 Enhances Ricinoleic Acid Content at the sn-2 Position of Triacylglycerols in Lesquerella Seed

by Grace Q. Chen, Harrie Van Erp, Jose Martin-Moreno, Kumiko Johnson, Eva Morales, John Browse, Peter J. Eastmond and Jiann-Tsyh Lin

Int. J. Mol. Sci. 2016, 17(4), 507; https://doi.org/10.3390/ijms17040507 - 6 Apr 2016

Cited by 39 | Viewed by 7543

Abstract

Lesquerella is a potential industrial oilseed crop that makes hydroxy fatty acid (HFA). Unlike castor its seeds are not poisonous but accumulate lesquerolic acid mostly at the sn-1 and sn-3 positions of triacylglycerol (TAG), whereas castor contains ricinoleic acid (18:1OH) at [...] Read more.

Lesquerella is a potential industrial oilseed crop that makes hydroxy fatty acid (HFA). Unlike castor its seeds are not poisonous but accumulate lesquerolic acid mostly at the sn-1 and sn-3 positions of triacylglycerol (TAG), whereas castor contains ricinoleic acid (18:1OH) at all three positions. To investigate whether lesquerella can be engineered to accumulate HFAs in the sn-2 position, multiple transgenic lines were made that express castor lysophosphatidic acid acyltransferase 2 (RcLPAT2) in the seed. RcLPAT2 increased 18:1OH at the sn-2 position of TAGs from 2% to 14%–17%, which resulted in an increase of tri-HFA-TAGs from 5% to 13%–14%. Our result is the first example of using a LPAT to increase ricinoleic acid at the sn-2 position of seed TAG. This work provides insights to the mechanism of HFA-containing TAG assembly in lesquerella and directs future research to optimize this plant for HFA production. Full article

(This article belongs to the Special Issue Metabolomics in the Plant Sciences)

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Open AccessArticle

Development and Characterization of Novel Microsatellite Markers for the Peach Fruit Moth Carposina sasakii (Lepidoptera: Carposinidae) Using Next-Generation Sequencing

by You-Zhu Wang, Li-Jun Cao, Jia-Ying Zhu and Shu-Jun Wei

Int. J. Mol. Sci. 2016, 17(3), 362; https://doi.org/10.3390/ijms17030362 - 15 Mar 2016

Cited by 20 | Viewed by 5074

Abstract

The peach fruit moth Carposina sasakii is an economically important pest on dozens of fruits from Rosaceae and Rhamnaceae in Northeast Asia. We developed novel microsatellite markers for C. sasakii from randomly sequenced regions of the genome using next-generation sequencing. In total, 95,153 [...] Read more.

The peach fruit moth Carposina sasakii is an economically important pest on dozens of fruits from Rosaceae and Rhamnaceae in Northeast Asia. We developed novel microsatellite markers for C. sasakii from randomly sequenced regions of the genome using next-generation sequencing. In total, 95,153 microsatellite markers were isolated from 4.70 GB genomic sequences. Thirty-five polymorphic markers were developed by assessing in 63 individuals from two geographical populations. The allele numbers ranged from 2 to 9 with an average value of 4.60 per locus, while the polymorphism information content ranged from 0.075 to 0.696 with an average value of 0.407. Furthermore, the observed and expected heterozygosity varied from 0.000 to 0.677 and 0.062 to 0.771, respectively. The microsatellites developed provide abundant molecular markers for investigating genetic structure, genetic diversity, and existence of host-plant associated biotypes of C. sasakii. Full article

(This article belongs to the Special Issue Plant Molecular Biology)

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Open AccessArticle

Genetic Diversity and Population Structure of Broomcorn Millet (Panicum miliaceum L.) Cultivars and Landraces in China Based on Microsatellite Markers

by Minxuan Liu, Yue Xu, Jihong He, Shuang Zhang, Yinyue Wang and Ping Lu

Int. J. Mol. Sci. 2016, 17(3), 370; https://doi.org/10.3390/ijms17030370 - 14 Mar 2016

Cited by 57 | Viewed by 6963

Abstract

Broomcorn millet (Panicum miliaceum L.), one of the first domesticated crops, has been grown in Northern China for at least 10,000 years. The species is presently a minor crop, and evaluation of its genetic diversity has been very limited. In this study, [...] Read more.

Broomcorn millet (Panicum miliaceum L.), one of the first domesticated crops, has been grown in Northern China for at least 10,000 years. The species is presently a minor crop, and evaluation of its genetic diversity has been very limited. In this study, we analyzed the genetic diversity of 88 accessions of broomcorn millet collected from various provinces of China. Amplification with 67 simple sequence repeat (SSR) primers revealed moderate levels of diversity in the investigated accessions. A total of 179 alleles were detected, with an average of 2.7 alleles per locus. Polymorphism information content and expected heterozygosity ranged from 0.043 to 0.729 (mean = 0.376) and 0.045 to 0.771 (mean = 0.445), respectively. Cluster analysis based on the unweighted pair group method of mathematical averages separated the 88 accessions into four groups at a genetic similarity level of 0.633. A genetic structure assay indicated a close correlation between geographical regions and genetic diversity. The uncovered information will be valuable for defining gene pools and developing breeding programs for broomcorn millet. Furthermore, the millet-specific SSR markers developed in this study should serve as useful tools for assessment of genetic diversity and elucidation of population structure in broomcorn millet. Full article

(This article belongs to the Special Issue Plant Molecular Biology)

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Identification, Functional Study, and Promoter Analysis of HbMFT1, a Homolog of MFT from Rubber Tree (Hevea brasiliensis)

by Zhenghong Bi, Xiang Li, Huasun Huang and Yuwei Hua

Int. J. Mol. Sci. 2016, 17(3), 247; https://doi.org/10.3390/ijms17030247 - 2 Mar 2016

Cited by 24 | Viewed by 6692

Abstract

A homolog of MOTHER OF FT AND TFL1 (MFT) was isolated from Hevea brasiliensis and its biological function was investigated. Protein multiple sequence alignment and phylogenetic analysis revealed that HbMFT1 conserved critical amino acid residues to distinguish MFT, FLOWERING LOCUS T [...] Read more.

A homolog of MOTHER OF FT AND TFL1 (MFT) was isolated from Hevea brasiliensis and its biological function was investigated. Protein multiple sequence alignment and phylogenetic analysis revealed that HbMFT1 conserved critical amino acid residues to distinguish MFT, FLOWERING LOCUS T (FT) and TERMINAL FLOWER1 (TFL1)-like proteins and showed a closer genetic relationship to the MFT-like group. The accumulation of HbMFT1 was generally detected in various tissues except pericarps, with the highest expression in embryos and relatively higher expression in roots and stems of seedlings, flowering inflorescences, and male and female flowers. HbMFT1 putative promoter analysis showed that tissue-specific, environmental change responsive and hormone-signaling responsive elements were generally present. HbMFT1 was strongly induced under a short-day condition at 28 °C, with the highest expression after the onset of a day. Overexpression of HbMFT1 inhibited seed germination, seedling growth, and flowering in transgenic Arabidopsis. The qRT-PCR further confirmed that APETALA1 (AP1) and FRUITFULL (FUL) were drastically down-regulated in 35S::HbMFT1 plants. A histochemical β-glucuronidase (GUS) assay showed that HbMFT1::GUS activity was mainly detected in stamens and mature seeds coinciding with its original expression and notably induced in rosette leaves and seedlings of transgenic Arabidopsis by exogenous abscisic acid (ABA) due to the presence of ABA cis-elements in HbMFT1 promoter. These results suggested that HbMFT1 was mainly involved in maintenance of seed maturation and stamen development, but negatively controlled germination, growth and development of seedlings and flowering. In addition, the HbMFT1 promoter can be utilized in controlling transgene expression in stamens and seeds of rubber tree or other plant species. Full article

(This article belongs to the Special Issue Plant Molecular Biology)

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Open AccessArticle

AfAP2-1, An Age-Dependent Gene of Aechmea fasciata, Responds to Exogenous Ethylene Treatment

by Ming Lei, Zhi-Ying Li, Jia-Bin Wang, Yun-Liu Fu, Meng-Fei Ao and Li Xu

Int. J. Mol. Sci. 2016, 17(3), 303; https://doi.org/10.3390/ijms17030303 - 27 Feb 2016

Cited by 6 | Viewed by 5646

Abstract

The Bromeliaceae family is one of the most morphologically diverse families with a pantropical distribution. To schedule an appropriate flowering time for bromeliads, ethylene is commonly used to initiate flower development in adult plants. However, the mechanism by which ethylene induces flowering in [...] Read more.

The Bromeliaceae family is one of the most morphologically diverse families with a pantropical distribution. To schedule an appropriate flowering time for bromeliads, ethylene is commonly used to initiate flower development in adult plants. However, the mechanism by which ethylene induces flowering in adult bromeliads remains unknown. Here, we identified an APETALA2 (AP2)-like gene, AfAP2-1, in Aechmea fasciata. AfAP2-1 contains two AP2 domains and is a nuclear-localized protein. It functions as a transcriptional activator, and the activation domain is located in the C-terminal region. The expression level of AfAP2-1 is higher in juvenile plants than in adult plants, and the AfAP2-1 transcript level was rapidly and transiently reduced in plants treated with exogenous ethylene. Overexpression of AfAP2-1 in Arabidopsis thaliana results in an extremely delayed flowering phenotype. These results suggested that AfAP2-1 responds to ethylene and is a putative age-dependent flowering regulator in A. fasciata. Full article

(This article belongs to the Special Issue Plant Molecular Biology)

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The Indeterminate Domain Protein ROC1 Regulates Chilling Tolerance via Activation of DREB1B/CBF1 in Rice

by Mingzhu Dou, Shuai Cheng, Baotian Zhao, Yuanhu Xuan and Minglong Shao

Int. J. Mol. Sci. 2016, 17(3), 233; https://doi.org/10.3390/ijms17030233 - 25 Feb 2016

Cited by 28 | Viewed by 6585

Abstract

Abiotic stress, including salinity, drought and cold, severely affect diverse aspects of plant development and production. Rice is an important crop that does not acclimate to cold; therefore, it is relatively sensitive to low temperature stress. Dehydration-responsive element-binding protein 1s (DREB1s)/C-repeat binding factors [...] Read more.

Abiotic stress, including salinity, drought and cold, severely affect diverse aspects of plant development and production. Rice is an important crop that does not acclimate to cold; therefore, it is relatively sensitive to low temperature stress. Dehydration-responsive element-binding protein 1s (DREB1s)/C-repeat binding factors (CBFs) are well known for their function in cold tolerance, but the transcriptional regulation of CBFs remains elusive, especially in rice. Here, we performed a yeast one-hybrid assay using the promoter of CBF1, a cold-induced gene, to isolate transcriptional regulators of CBF1. Among the seven candidates identified, an indeterminate domain (IDD) protein named ROC1 (a regulator of CBF1) was further analyzed. The ROC1 transcript was induced by exogenously-treated auxin, while it was not altered by cold or ABA stimuli. ROC1-GFP was localized at the nucleus, and ROC1 showed trans-activation activity in yeast. The electrophoretic mobility shift assay (EMSA) and ChIP analyses revealed that ROC1 directly bound to the promoter of CBF1. Furthermore, ROC1 mutants exhibited chilling-sensitive symptoms and inhibited cold-mediated induction of CBF1 and CBF3, indicating that ROC1 is a positive regulator of cold stress responses. Taken together, this study identified the CBF1 regulator, and the results are important for rice plant adaptation to chilling stress. Full article

(This article belongs to the Special Issue Plant Molecular Biology)

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Cloning and Characterization of a Flavonoid 3′-Hydroxylase Gene from Tea Plant (Camellia sinensis)

by Tian-Shan Zhou, Rui Zhou, You-Ben Yu, Yao Xiao, Dong-Hua Li, Bin Xiao, Oliver Yu and Ya-Jun Yang

Int. J. Mol. Sci. 2016, 17(2), 261; https://doi.org/10.3390/ijms17020261 - 22 Feb 2016

Cited by 39 | Viewed by 8190

Abstract

Tea leaves contain abundant flavan-3-ols, which include dihydroxylated and trihydroxylated catechins. Flavonoid 3′-hydroxylase (F3′H: EC 1.14.13.21) is one of the enzymes in the establishment of the hydroxylation pattern. A gene encoding F3′H, designated as CsF3′H, was isolated from Camellia sinensis [...] Read more.

Tea leaves contain abundant flavan-3-ols, which include dihydroxylated and trihydroxylated catechins. Flavonoid 3′-hydroxylase (F3′H: EC 1.14.13.21) is one of the enzymes in the establishment of the hydroxylation pattern. A gene encoding F3′H, designated as CsF3′H, was isolated from Camellia sinensis with a homology-based cloning technique and deposited in the GenBank (GenBank ID: KT180309). Bioinformatic analysis revealed that CsF3′H was highly homologous with the characterized F3′Hs from other plant species. Four conserved cytochrome P450-featured motifs and three F3′H-specific conserved motifs were discovered in the protein sequence of CsF3′H. Enzymatic analysis of the heterologously expressed CsF3′H in yeast demonstrated that tea F3′H catalyzed the 3′-hydroxylation of naringenin, dihydrokaempferol and kaempferol. Apparent K_m values for these substrates were 17.08, 143.64 and 68.06 μM, and their apparent V_max values were 0.98, 0.19 and 0.44 pM·min⁻¹, respectively. Transcription level of CsF3′H in the new shoots, during tea seed germination was measured, along with that of other key genes for flavonoid biosynthesis using real-time PCR technique. The changes in 3′,4′-flavan-3-ols, 3′,4′,5′-flavan-3-ols and flavan-3-ols, were consistent with the expression level of CsF3′H and other related genes in the leaves. In the study of nitrogen supply for the tea plant growth, our results showed the expression level of CsF3′H and all other tested genes increased in response to nitrogen depletion after 12 days of treatment, in agreement with a corresponding increase in 3′,4′-catechins, 3′,4′,5′-catechins and flavan 3-ols content in the leaves. All these results suggest the importance of CsF3′H in the biosynthesis of 3′,4′-catechins, 3′,4′,5′-catechins and flavan 3-ols in tea leaves. Full article

(This article belongs to the Special Issue Molecular Research in Plant Secondary Metabolism 2015)

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Investigation of the Antiproliferative Properties of Natural Sesquiterpenes from Artemisia asiatica and Onopordum acanthium on HL-60 Cells in Vitro

by Judit Molnár, Gábor J. Szebeni, Boglárka Csupor-Löffler, Zsuzsanna Hajdú, Thomas Szekeres, Philipp Saiko, Imre Ocsovszki, László G. Puskás, Judit Hohmann and István Zupkó

Int. J. Mol. Sci. 2016, 17(2), 83; https://doi.org/10.3390/ijms17020083 - 17 Feb 2016

Cited by 18 | Viewed by 6476

Abstract

Plants and plant extracts play a crucial role in the research into novel antineoplastic agents. Four sesquiterpene lactones, artecanin (1), 3β-chloro-4α,10α-dihydroxy-1α,2α-epoxy-5α,7αH-guaia-11(13)-en-12,6α-olide (2), iso-seco-tanapartholide 3-O-methyl ether (3) and 4β,15-dihydro-3-dehydrozaluzanin C (4), were isolated from two [...] Read more.

Plants and plant extracts play a crucial role in the research into novel antineoplastic agents. Four sesquiterpene lactones, artecanin (1), 3β-chloro-4α,10α-dihydroxy-1α,2α-epoxy-5α,7αH-guaia-11(13)-en-12,6α-olide (2), iso-seco-tanapartholide 3-O-methyl ether (3) and 4β,15-dihydro-3-dehydrozaluzanin C (4), were isolated from two traditionally used Asteraceae species (Onopordum acanthium and Artemisia asiatica). When tested for antiproliferative action on HL-60 leukemia cells, these compounds exhibited reasonable IC₅₀ values in the range 3.6–13.5 μM. Treatment with the tested compounds resulted in a cell cycle disturbance characterized by increases in the G1 and G2/M populations, while there was a decrease in the S phase. Additionally, 1–3 elicited increases in the hypodiploid (subG1) population. The compounds elicited concentration-dependent chromatin condensation and disruption of the membrane integrity, as revealed by Hoechst 33258–propidium staining. Treatment for 24 h resulted in significant increases in activity of caspases-3 and -9, indicating that the tested sesquiterpenes induced the mitochondrial pathway of apoptosis. The proapoptotic properties of the sesquiterpene lactones were additionally demonstrated withannexin V staining. Compounds 1 and 2 increased the Bax/Bcl-2 expression and decreased the expressions of CDK1 and cyclin B2, as determined at the mRNA level by means of RT-PCR. These experimental results indicate that sesquiterpene lactones may be regarded as potential starting structures for the development of novel anticancer agents. Full article

(This article belongs to the Special Issue Molecular Research in Plant Secondary Metabolism 2015)

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Use of Repetitive Sequences for Molecular and Cytogenetic Characterization of Avena Species from Portugal

by Diana Tomás, Joana Rodrigues, Ana Varela, Maria Manuela Veloso, Wanda Viegas and Manuela Silva

Int. J. Mol. Sci. 2016, 17(2), 203; https://doi.org/10.3390/ijms17020203 - 4 Feb 2016

Cited by 14 | Viewed by 5644

Abstract

Genomic diversity of Portuguese accessions of Avena species—diploid A. strigosa and hexaploids A. sativa and A. sterilis—was evaluated through molecular and cytological analysis of 45S rDNA, and other repetitive sequences previously studied in cereal species—rye subtelomeric sequence (pSc200) and cereal centromeric sequence [...] Read more.

Genomic diversity of Portuguese accessions of Avena species—diploid A. strigosa and hexaploids A. sativa and A. sterilis—was evaluated through molecular and cytological analysis of 45S rDNA, and other repetitive sequences previously studied in cereal species—rye subtelomeric sequence (pSc200) and cereal centromeric sequence (CCS1). Additionally, retrotransposons and microsatellites targeting methodologies—IRAP (inter-retrotransposon amplified polymorphism) and REMAP (retrotransposon-microsatellite amplified polymorphism)—were performed. A very high homology was detected for ribosomal internal transcribed sequences (ITS1 and ITS2) between the species analyzed, although nucleolar organizing regions (NOR) fluorescent in situ hybridization (FISH) analysis revealed distinct number of Nor loci between diploid and hexaploid species. Moreover, morphological diversity, evidenced by FISH signals with different sizes, was observed between distinct accessions within each species. pSc200 sequences were for the first time isolated from Avena species but proven to be highly similar in all genotypes analyzed. The use of primers designed for CCS1 unraveled a sequence homologous to the Ty3/gypsy retrotransposon Cereba, that was mapped to centromeric regions of diploid and hexaploid species, being however restricted to the more related A and D haplomes. Retrotransposon-based methodologies disclosed species- and accessions-specific bands essential for the accurate discrimination of all genotypes studied. Centromeric, IRAP and REMAP profiles therefore allowed accurate assessment of inter and intraspecific variability, demonstrating the potential of these molecular markers on future oat breeding programs. Full article

(This article belongs to the Special Issue Plant Molecular Biology)

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Identification of Powdery Mildew Responsive Genes in Hevea brasiliensis through mRNA Differential Display

by Xiang Li, Zhenghong Bi, Rong Di, Peng Liang, Qiguang He, Wenbo Liu, Weiguo Miao and Fucong Zheng

Int. J. Mol. Sci. 2016, 17(2), 181; https://doi.org/10.3390/ijms17020181 - 29 Jan 2016

Cited by 20 | Viewed by 6297

Abstract

Powdery mildew is an important disease of rubber trees caused by Oidium heveae B. A. Steinmann. As far as we know, none of the resistance genes related to powdery mildew have been isolated from the rubber tree. There is little information available at [...] Read more.

Powdery mildew is an important disease of rubber trees caused by Oidium heveae B. A. Steinmann. As far as we know, none of the resistance genes related to powdery mildew have been isolated from the rubber tree. There is little information available at the molecular level regarding how a rubber tree develops defense mechanisms against this pathogen. We have studied rubber tree mRNA transcripts from the resistant RRIC52 cultivar by differential display analysis. Leaves inoculated with the spores of O. heveae were collected from 0 to 120 hpi in order to identify pathogen-regulated genes at different infection stages. We identified 78 rubber tree genes that were differentially expressed during the plant–pathogen interaction. BLAST analysis for these 78 ESTs classified them into seven functional groups: cell wall and membrane pathways, transcription factor and regulatory proteins, transporters, signal transduction, phytoalexin biosynthesis, other metabolism functions, and unknown functions. The gene expression for eight of these genes was validated by qRT-PCR in both RRIC52 and the partially susceptible Reyan 7-33-97 cultivars, revealing the similar or differential changes of gene expressions between these two cultivars. This study has improved our overall understanding of the molecular mechanisms of rubber tree resistance to powdery mildew. Full article

(This article belongs to the Special Issue Plant Molecular Biology)

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Genome-Wide Identification, Characterization and Expression Analysis of the Chalcone Synthase Family in Maize

by Yahui Han, Ting Ding, Bo Su and Haiyang Jiang

Int. J. Mol. Sci. 2016, 17(2), 161; https://doi.org/10.3390/ijms17020161 - 27 Jan 2016

Cited by 86 | Viewed by 8325

Abstract

Members of the chalcone synthase (CHS) family participate in the synthesis of a series of secondary metabolites in plants, fungi and bacteria. The metabolites play important roles in protecting land plants against various environmental stresses during the evolutionary process. Our research was conducted [...] Read more.

Members of the chalcone synthase (CHS) family participate in the synthesis of a series of secondary metabolites in plants, fungi and bacteria. The metabolites play important roles in protecting land plants against various environmental stresses during the evolutionary process. Our research was conducted on comprehensive investigation of CHS genes in maize (Zea mays L.), including their phylogenetic relationships, gene structures, chromosomal locations and expression analysis. Fourteen CHS genes (ZmCHS01–14) were identified in the genome of maize, representing one of the largest numbers of CHS family members identified in one organism to date. The gene family was classified into four major classes (classes I–IV) based on their phylogenetic relationships. Most of them contained two exons and one intron. The 14 genes were unevenly located on six chromosomes. Two segmental duplication events were identified, which might contribute to the expansion of the maize CHS gene family to some extent. In addition, quantitative real-time PCR and microarray data analyses suggested that ZmCHS genes exhibited various expression patterns, indicating functional diversification of the ZmCHS genes. Our results will contribute to future studies of the complexity of the CHS gene family in maize and provide valuable information for the systematic analysis of the functions of the CHS gene family. Full article

(This article belongs to the Special Issue Molecular Research in Plant Secondary Metabolism 2015)

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Comparative Transcriptome Profile of the Cytoplasmic Male Sterile and Fertile Floral Buds of Radish (Raphanus sativus L.)

by Shiyong Mei, Touming Liu and Zhiwei Wang

Int. J. Mol. Sci. 2016, 17(1), 42; https://doi.org/10.3390/ijms17010042 - 6 Jan 2016

Cited by 31 | Viewed by 8623

Abstract

Radish cytoplasmic male sterility (CMS) has been widely used for breeding in Raphanus and Brassica genera. However, the detailed regulation network of the male sterility remains to be determined. Our previous work has shown that the abnormalities in a CMS radish appeared shortly [...] Read more.

Radish cytoplasmic male sterility (CMS) has been widely used for breeding in Raphanus and Brassica genera. However, the detailed regulation network of the male sterility remains to be determined. Our previous work has shown that the abnormalities in a CMS radish appeared shortly after the tetrad stage when microspores were malformed and the tapetal cells grew abnormally large. In this work, histological analysis shows that anthers are at the tetrad stage when the radish buds are about 1.5 mm in length. Furthermore, a high throughput RNA sequencing technology was employed to characterize the transcriptome of radish buds with length about 1.5 mm from two CMS lines possessing the CMS-inducing orf138 gene and corresponding near-isogenic maintainer lines. A total of 67,140 unigenes were functionally annotated. Functional terms for these genes are significantly enriched in 55 Gene Ontology (GO) groups and 323 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. The transcriptome detected transcripts for 72 out of a total of 79 protein genes encoded in the chloroplast genome from radish. In contrast, the radish mitochondrial genome contains 34 protein genes, but only 16 protein transcripts were detected from the transcriptome. The transcriptome comparison between CMS and near-isogenic maintainer lines revealed 539 differentially expressed genes (DEGs), indicating that the false positive rate for comparative transcriptome profiling was clearly decreased using two groups of CMS/maintainer lines with different nuclear background. The level of 127 transcripts was increased and 412 transcripts were decreased in the CMS lines. No change in levels of transcripts except CMS-inducing orf138 was identified from the mitochondrial and chloroplast genomes. Some DEGs which would be associated with the CMS, encoding MYB and bHLH transcription factors, pentatricopeptide repeat (PPR) proteins, heat shock transcription factors (HSFs) and heat shock proteins (HSPs), are discussed. The transcriptome dataset and comparative analysis will provide an important resource for further understanding anther development, the CMS mechanism and to improve molecular breeding in radish. Full article

(This article belongs to the Special Issue Plant Molecular Biology)

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Anion Channel Inhibitor NPPB-Inhibited Fluoride Accumulation in Tea Plant (Camellia sinensis) Is Related to the Regulation of Ca²⁺, CaM and Depolarization of Plasma Membrane Potential

by Xian-Chen Zhang, Hong-Jian Gao, Tian-Yuan Yang, Hong-Hong Wu, Yu-Mei Wang, Zheng-Zhu Zhang and Xiao-Chun Wan

Int. J. Mol. Sci. 2016, 17(1), 57; https://doi.org/10.3390/ijms17010057 - 5 Jan 2016

Cited by 149 | Viewed by 6320

Abstract

Tea plant is known to be a hyper-accumulator of fluoride (F). Over-intake of F has been shown to have adverse effects on human health, e.g., dental fluorosis. Thus, understanding the mechanisms fluoride accumulation and developing potential approaches to decrease F uptake in tea [...] Read more.

Tea plant is known to be a hyper-accumulator of fluoride (F). Over-intake of F has been shown to have adverse effects on human health, e.g., dental fluorosis. Thus, understanding the mechanisms fluoride accumulation and developing potential approaches to decrease F uptake in tea plants might be beneficial for human health. In the present study, we found that pretreatment with the anion channel inhibitor NPPB reduced F accumulation in tea plants. Simultaneously, we observed that NPPB triggered Ca²⁺ efflux from mature zone of tea root and significantly increased relative CaM in tea roots. Besides, pretreatment with the Ca²⁺ chelator (EGTA) and CaM antagonists (CPZ and TFP) suppressed NPPB-elevated cytosolic Ca²⁺ fluorescence intensity and CaM concentration in tea roots, respectively. Interestingly, NPPB-inhibited F accumulation was found to be significantly alleviated in tea plants pretreated with either Ca²⁺ chelator (EGTA) or CaM antagonists (CPZ and TFP). In addition, NPPB significantly depolarized membrane potential transiently and we argue that the net Ca²⁺ and H⁺ efflux across the plasma membrane contributed to the restoration of membrane potential. Overall, our results suggest that regulation of Ca²⁺-CaM and plasma membrane potential depolarization are involved in NPPB-inhibited F accumulation in tea plants. Full article

(This article belongs to the Special Issue Plant Molecular Biology)

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Cloning, Characterization and Expression Pattern Analysis of a Cytosolic Copper/Zinc Superoxide Dismutase (SaCSD1) in a Highly Salt Tolerant Mangrove (Sonneratia alba)

by Enze Yang, Shanze Yi, Fang Bai, Dewei Niu, Junjie Zhong, Qiuhong Wu, Shufang Chen, Renchao Zhou and Feng Wang

Int. J. Mol. Sci. 2016, 17(1), 4; https://doi.org/10.3390/ijms17010004 - 22 Dec 2015

Cited by 10 | Viewed by 5883

Abstract

Mangroves are critical marine resources for their remarkable ability to tolerate seawater. Antioxidant enzymes play an especially significant role in eliminating reactive oxygen species and conferring abiotic stress tolerance. In this study, a cytosolic copper/zinc superoxide dismutase (SaCSD1) cDNA of Sonneratia [...] Read more.

Mangroves are critical marine resources for their remarkable ability to tolerate seawater. Antioxidant enzymes play an especially significant role in eliminating reactive oxygen species and conferring abiotic stress tolerance. In this study, a cytosolic copper/zinc superoxide dismutase (SaCSD1) cDNA of Sonneratia alba, a mangrove species with high salt tolerance, was successfully cloned and then expressed in Escherichia coli Rosetta-gami (designated as SaCSD1). SaCSD1 comprised a complete open reading frame (ORF) of 459 bp which encoded a protein of 152 amino acids. Its mature protein is predicted to be 15.32 kDa and the deduced isoelectric point is 5.78. SaCSD1 has high sequence similarity (85%–90%) with the superoxide dismutase (CSD) of some other plant species. SaCSD1 was expressed with 30.6% yield regarding total protein content after being introduced into the pET-15b (Sma I) vector for expression in Rosetta-gami and being induced with IPTG. After affinity chromatography on Ni-NTA, recombinant SaCSD1 was obtained with 3.2-fold purification and a specific activity of 2200 U/mg. SaCSD1 showed good activity as well as stability in the ranges of pH between 3 and 7 and temperature between 25 and 55 °C. The activity of recombinant SaCSD1 was stable in 0.25 M NaCl, Dimethyl Sulphoxide (DMSO), glycerol, and chloroform, and was reduced to a great extent in β-mercaptoethanol, sodium dodecyl sulfate (SDS), H₂O_2, and phenol. Moreover, the SaCSD1 protein was very susceptive to pepsin digestion. Real-time Quantitative Polymerase Chain Reaction (PCR) assay demonstrated that SaCSD1 was expressed in leaf, stem, flower, and fruit organs, with the highest expression in fruits. Under 0.25 M and 0.5 M salt stress, the expression of SaCSD1 was down-regulated in roots, but up-regulated in leaves. Full article

(This article belongs to the Special Issue Plant Molecular Biology)

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Cloning of the Lycopene β-cyclase Gene in Nicotiana tabacum and Its Overexpression Confers Salt and Drought Tolerance

by Yanmei Shi, Jinggong Guo, Wei Zhang, Lifeng Jin, Pingping Liu, Xia Chen, Feng Li, Pan Wei, Zefeng Li, Wenzheng Li, Chunyang Wei, Qingxia Zheng, Qiansi Chen, Jianfeng Zhang, Fucheng Lin, Lingbo Qu, John Hugh Snyder and Ran Wang

Int. J. Mol. Sci. 2015, 16(12), 30438-30457; https://doi.org/10.3390/ijms161226243 - 21 Dec 2015

Cited by 38 | Viewed by 7160

Abstract

Carotenoids are important pigments in plants that play crucial roles in plant growth and in plant responses to environmental stress. Lycopene β cyclase (β-LCY) functions at the branch point of the carotenoid biosynthesis pathway, catalyzing the cyclization of lycopene. Here, a β-LCY gene [...] Read more.

Carotenoids are important pigments in plants that play crucial roles in plant growth and in plant responses to environmental stress. Lycopene β cyclase (β-LCY) functions at the branch point of the carotenoid biosynthesis pathway, catalyzing the cyclization of lycopene. Here, a β-LCY gene from Nicotiana tabacum, designated as Ntβ-LCY1, was cloned and functionally characterized. Robust expression of Ntβ-LCY1 was found in leaves, and Ntβ-LCY1 expression was obviously induced by salt, drought, and exogenous abscisic acid treatments. Strong accumulation of carotenoids and expression of carotenoid biosynthesis genes resulted from Ntβ-LCY1 overexpression. Additionally, compared to wild-type plants, transgenic plants with overexpression showed enhanced tolerance to salt and drought stress with higher abscisic acid levels and lower levels of malondialdehyde and reactive oxygen species. Conversely, transgenic RNA interference plants had a clear albino phenotype in leaves, and some plants did not survive beyond the early developmental stages. The suppression of Ntβ-LCY1 expression led to lower expression levels of genes in the carotenoid biosynthesis pathway and to reduced accumulation of carotenoids, chlorophyll, and abscisic acid. These results indicate that Ntβ-LCY1 is not only a likely cyclization enzyme involved in carotenoid accumulation but also confers salt and drought stress tolerance in Nicotiana tabacum. Full article

(This article belongs to the Special Issue Plant Molecular Biology)

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Effects of Heat Stress on Metabolite Accumulation and Composition, and Nutritional Properties of Durum Wheat Grain

by Anna Maria De Leonardis, Mariagiovanna Fragasso, Romina Beleggia, Donatella Bianca Maria Ficco, Pasquale De Vita and Anna Maria Mastrangelo

Int. J. Mol. Sci. 2015, 16(12), 30382-30404; https://doi.org/10.3390/ijms161226241 - 19 Dec 2015

Cited by 49 | Viewed by 7724

Abstract

Durum wheat (Triticum turgidum (L.) subsp. turgidum (L.) convar. durum (Desf.)) is momentous for human nutrition, and environmental stresses can strongly limit the expression of yield potential and affect the qualitative characteristics of the grain. The aim of this study was to [...] Read more.

Durum wheat (Triticum turgidum (L.) subsp. turgidum (L.) convar. durum (Desf.)) is momentous for human nutrition, and environmental stresses can strongly limit the expression of yield potential and affect the qualitative characteristics of the grain. The aim of this study was to determine how heat stress (five days at 37 °C) applied five days after flowering affects the nutritional composition, antioxidant capacity and metabolic profile of the grain of two durum wheat genotypes: “Primadur”, an elite cultivar with high yellow index, and “T1303”, an anthocyanin-rich purple cultivar. Qualitative traits and metabolite evaluation (by gas chromatography linked to mass spectrometry) were carried out on immature (14 days after flowering) and mature seeds. The effects of heat stress were genotype-dependent. Although some metabolites (e.g., sucrose, glycerol) increased in response to heat stress in both genotypes, clear differences were observed. Following the heat stress, there was a general increase in most of the analyzed metabolites in “Primadur”, with a general decrease in “T1303”. Heat shock applied early during seed development produced changes that were observed in immature seeds and also long-term effects that changed the qualitative and quantitative parameters of the mature grain. Therefore, short heat-stress treatments can affect the nutritional value of grain of different genotypes of durum wheat in different ways. Full article

(This article belongs to the Special Issue Metabolomics in the Plant Sciences)

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Comparative Transcriptome Analysis of Genes Involved in GA-GID1-DELLA Regulatory Module in Symbiotic and Asymbiotic Seed Germination of Anoectochilus roxburghii (Wall.) Lindl. (Orchidaceae)

by Si-Si Liu, Juan Chen, Shu-Chao Li, Xu Zeng, Zhi-Xia Meng and Shun-Xing Guo

Int. J. Mol. Sci. 2015, 16(12), 30190-30203; https://doi.org/10.3390/ijms161226224 - 18 Dec 2015

Cited by 53 | Viewed by 9952

Abstract

Anoectochilus roxburghii (Wall.) Lindl. (Orchidaceae) is an endangered medicinal plant in China, also called “King Medicine”. Due to lacking of sufficient nutrients in dust-like seeds, orchid species depend on mycorrhizal fungi for seed germination in the wild. As part of a conservation plan [...] Read more.

Anoectochilus roxburghii (Wall.) Lindl. (Orchidaceae) is an endangered medicinal plant in China, also called “King Medicine”. Due to lacking of sufficient nutrients in dust-like seeds, orchid species depend on mycorrhizal fungi for seed germination in the wild. As part of a conservation plan for the species, research on seed germination is necessary. However, the molecular mechanism of seed germination and underlying orchid-fungus interactions during symbiotic germination are poorly understood. In this study, Illumina HiSeq 4000 transcriptome sequencing was performed to generate a substantial sequence dataset of germinating A. roxburghii seed. A mean of 44,214,845 clean reads were obtained from each sample. 173,781 unigenes with a mean length of 653 nt were obtained. A total of 51,514 (29.64%) sequences were annotated, among these, 49 unigenes encoding proteins involved in GA-GID1-DELLA regulatory module, including 31 unigenes involved in GA metabolism pathway, 5 unigenes encoding GID1, 11 unigenes for DELLA and 2 unigenes for GID2. A total of 11,881 genes showed significant differential expression in the symbiotic germinating seed sample compared with the asymbiotic germinating seed sample, of which six were involved in the GA-GID1-DELLA regulatory module, and suggested that they might be induced or suppressed by fungi. These results will help us understand better the molecular mechanism of orchid seed germination and orchid-fungus symbiosis. Full article

(This article belongs to the Special Issue Plant Molecular Biology)

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Exogenous Spermidine Alleviates Low Temperature Injury in Mung Bean (Vigna radiata L.) Seedlings by Modulating Ascorbate-Glutathione and Glyoxalase Pathway

by Kamrun Nahar, Mirza Hasanuzzaman, Md. Mahabub Alam and Masayuki Fujita

Int. J. Mol. Sci. 2015, 16(12), 30117-30132; https://doi.org/10.3390/ijms161226220 - 17 Dec 2015

Cited by 80 | Viewed by 7814

Abstract

The role of exogenous spermidine (Spd) in alleviating low temperature (LT) stress in mung bean (Vigna radiata L. cv. BARI Mung-3) seedlings has been investigated. Low temperature stress modulated the non-enzymatic and enzymatic components of ascorbate-glutathione (AsA-GSH) cycle, increased H₂O [...] Read more.

The role of exogenous spermidine (Spd) in alleviating low temperature (LT) stress in mung bean (Vigna radiata L. cv. BARI Mung-3) seedlings has been investigated. Low temperature stress modulated the non-enzymatic and enzymatic components of ascorbate-glutathione (AsA-GSH) cycle, increased H₂O₂ content and lipid peroxidation, which indicate oxidative damage of seedlings. Low temperature reduced the leaf relative water content (RWC) and destroyed leaf chlorophyll, which inhibited seedlings growth. Exogenous pretreatment of Spd in LT-affected seedlings significantly increased the contents of non-enzymatic antioxidants of AsA-GSH cycle, which include AsA and GSH. Exogenous Spd decreased dehydroascorbate (DHA), increased AsA/DHA ratio, decreased glutathione disulfide (GSSG) and increased GSH/GSSG ratio under LT stress. Activities of AsA-GSH cycle enzymes such as ascorbate peroxidase (APX), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR) and glutathione reductase (GR) increased after Spd pretreatment in LT affected seedlings. Thus, the oxidative stress was reduced. Protective effects of Spd are also reflected from reduction of methylglyoxal (MG) toxicity by improving glyoxalase cycle components, and by maintaining osmoregulation, water status and improved seedlings growth. The present study reveals the vital roles of AsA-GSH and glyoxalase cycle in alleviating LT injury. Full article

(This article belongs to the Special Issue Plant Molecular Biology)

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Open AccessArticle

Biosynthesis of Essential Polyunsaturated Fatty Acids in Wheat Triggered by Expression of Artificial Gene

by Daniel Mihálik, Lenka Klčová, Katarína Ondreičková, Martina Hudcovicová, Marcela Gubišová, Tatiana Klempová, Milan Čertík, János Pauk and Ján Kraic

Int. J. Mol. Sci. 2015, 16(12), 30046-30060; https://doi.org/10.3390/ijms161226137 - 16 Dec 2015

Cited by 11 | Viewed by 6595

Abstract

The artificial gene D6D encoding the enzyme ∆⁶desaturase was designed and synthesized using the sequence of the same gene from the fungus Thamnidium elegans. The original start codon was replaced by the signal sequence derived from the wheat gene for [...] Read more.

The artificial gene D6D encoding the enzyme ∆⁶desaturase was designed and synthesized using the sequence of the same gene from the fungus Thamnidium elegans. The original start codon was replaced by the signal sequence derived from the wheat gene for high-molecular-weight glutenin subunit and the codon usage was completely changed for optimal expression in wheat. Synthesized artificial D6D gene was delivered into plants of the spring wheat line CY-45 and the gene itself, as well as transcribed D6D mRNA were confirmed in plants of T₀ and T₁ generations. The desired product of the wheat genetic modification by artificial D6D gene was the γ-linolenic acid. Its presence was confirmed in mature grains of transgenic wheat plants in the amount 0.04%–0.32% (v/v) of the total amount of fatty acids. Both newly synthesized γ-linolenic acid and stearidonic acid have been detected also in leaves, stems, roots, awns, paleas, rachillas, and immature grains of the T₁ generation as well as in immature and mature grains of the T₂ generation. Contents of γ-linolenic acid and stearidonic acid varied in range 0%–1.40% (v/v) and 0%–1.53% (v/v) from the total amount of fatty acids, respectively. This approach has opened the pathway of desaturation of fatty acids and production of essential polyunsaturated fatty acids in wheat. Full article

(This article belongs to the Special Issue Metabolomics in the Plant Sciences)

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Elicitation of Diosgenin Production in Trigonella foenum-graecum (Fenugreek) Seedlings by Methyl Jasmonate

by Spandan Chaudhary, Surendra K. Chikara, Mahesh C. Sharma, Abhinav Chaudhary, Bakhtiyar Alam Syed, Pooja S. Chaudhary, Aditya Mehta, Maulik Patel, Arpita Ghosh and Marcello Iriti

Int. J. Mol. Sci. 2015, 16(12), 29889-29899; https://doi.org/10.3390/ijms161226208 - 15 Dec 2015

Cited by 54 | Viewed by 8711

Abstract

The effects of methyl jasmonate (MeJA), an elicitor of plant defense mechanisms, on the biosynthesis of diosgenin, a steroidal saponin, were investigated in six fenugreek (Trigonella foenum-graecum) varieties (Gujarat Methi-2, Kasuri-1, Kasuri-2, Pusa Early Branching, Rajasthan Methi and Maharashtra Methi-5). Treatment [...] Read more.

The effects of methyl jasmonate (MeJA), an elicitor of plant defense mechanisms, on the biosynthesis of diosgenin, a steroidal saponin, were investigated in six fenugreek (Trigonella foenum-graecum) varieties (Gujarat Methi-2, Kasuri-1, Kasuri-2, Pusa Early Branching, Rajasthan Methi and Maharashtra Methi-5). Treatment with 0.01% MeJA increased diosgenin levels, in 12 days old seedlings, from 0.5%–0.9% to 1.1%–1.8%. In addition, MeJA upregulated the expression of two pivotal genes of the mevalonate pathway, the metabolic route leading to diosgenin: 3-hydroxy-3-methylglutaryl-CoA reductase (HMG) and sterol-3-β-glucosyl transferase (STRL). In particular, MeJA increased the expression of HMG and STRL genes by 3.2- and 22.2-fold, respectively, in the Gujarat Methi-2 variety, and by 25.4- and 28.4-fold, respectively, in the Kasuri-2 variety. Therefore, MeJA may be considered a promising elicitor for diosgenin production by fenugreek plants. Full article

(This article belongs to the Special Issue Molecular Research in Plant Secondary Metabolism 2015)

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De Novo Transcriptome Sequencing of Oryza officinalis Wall ex Watt to Identify Disease-Resistance Genes

by Bin He, Yinghong Gu, Xiang Tao, Xiaojie Cheng, Changhe Wei, Jian Fu, Zaiquan Cheng and Yizheng Zhang

Int. J. Mol. Sci. 2015, 16(12), 29482-29495; https://doi.org/10.3390/ijms161226178 - 10 Dec 2015

Cited by 14 | Viewed by 5854

Abstract

Oryza officinalis Wall ex Watt is one of the most important wild relatives of cultivated rice and exhibits high resistance to many diseases. It has been used as a source of genes for introgression into cultivated rice. However, there are limited genomic resources [...] Read more.

Oryza officinalis Wall ex Watt is one of the most important wild relatives of cultivated rice and exhibits high resistance to many diseases. It has been used as a source of genes for introgression into cultivated rice. However, there are limited genomic resources and little genetic information publicly reported for this species. To better understand the pathways and factors involved in disease resistance and accelerating the process of rice breeding, we carried out a de novo transcriptome sequencing of O. officinalis. In this research, 137,229 contigs were obtained ranging from 200 to 19,214 bp with an N50 of 2331 bp through de novo assembly of leaves, stems and roots in O. officinalis using an Illumina HiSeq 2000 platform. Based on sequence similarity searches against a non-redundant protein database, a total of 88,249 contigs were annotated with gene descriptions and 75,589 transcripts were further assigned to GO terms. Candidate genes for plant–pathogen interaction and plant hormones regulation pathways involved in disease-resistance were identified. Further analyses of gene expression profiles showed that the majority of genes related to disease resistance were all expressed in the three tissues. In addition, there are two kinds of rice bacterial blight-resistant genes in O. officinalis, including two Xa1 genes and three Xa26 genes. All 2 Xa1 genes showed the highest expression level in stem, whereas one of Xa26 was expressed dominantly in leaf and other 2 Xa26 genes displayed low expression level in all three tissues. This transcriptomic database provides an opportunity for identifying the genes involved in disease-resistance and will provide a basis for studying functional genomics of O. officinalis and genetic improvement of cultivated rice in the future. Full article

(This article belongs to the Special Issue Plant Molecular Biology)

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Allyl Isothiocyanate Inhibits Actin-Dependent Intracellular Transport in Arabidopsis thaliana

by Bjørnar Sporsheim, Anders Øverby and Atle Magnar Bones

Int. J. Mol. Sci. 2015, 16(12), 29134-29147; https://doi.org/10.3390/ijms161226154 - 7 Dec 2015

Cited by 11 | Viewed by 6467

Abstract

Volatile allyl isothiocyanate (AITC) derives from the biodegradation of the glucosinolate sinigrin and has been associated with growth inhibition in several plants, including the model plant Arabidopsis thaliana. However, the underlying cellular mechanisms of this feature remain scarcely investigated in plants. In [...] Read more.

Volatile allyl isothiocyanate (AITC) derives from the biodegradation of the glucosinolate sinigrin and has been associated with growth inhibition in several plants, including the model plant Arabidopsis thaliana. However, the underlying cellular mechanisms of this feature remain scarcely investigated in plants. In this study, we present evidence of an AITC-induced inhibition of actin-dependent intracellular transport in A. thaliana. A transgenic line of A. thaliana expressing yellow fluorescent protein (YFP)-tagged actin filaments was used to show attenuation of actin filament movement by AITC. This appeared gradually in a time- and dose-dependent manner and resulted in actin filaments appearing close to static. Further, we employed four transgenic lines with YFP-fusion proteins labeling the Golgi apparatus, endoplasmic reticulum (ER), vacuoles and peroxisomes to demonstrate an AITC-induced inhibition of actin-dependent intracellular transport of or, in these structures, consistent with the decline in actin filament movement. Furthermore, the morphologies of actin filaments, ER and vacuoles appeared aberrant following AITC-exposure. However, AITC-treated seedlings of all transgenic lines tested displayed morphologies and intracellular movements similar to that of the corresponding untreated and control-treated plants, following overnight incubation in an AITC-absent environment, indicating that AITC-induced decline in actin-related movements is a reversible process. These findings provide novel insights into the cellular events in plant cells following exposure to AITC, which may further expose clues to the physiological significance of the glucosinolate-myrosinase system. Full article

(This article belongs to the Special Issue Plant Molecular Biology)

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De Novo Transcriptome Sequencing Analysis of cDNA Library and Large-Scale Unigene Assembly in Japanese Red Pine (Pinus densiflora)

by Le Liu, Shijie Zhang and Chunlan Lian

Int. J. Mol. Sci. 2015, 16(12), 29047-29059; https://doi.org/10.3390/ijms161226139 - 4 Dec 2015

Cited by 14 | Viewed by 6003

Abstract

Japanese red pine (Pinus densiflora) is extensively cultivated in Japan, Korea, China, and Russia and is harvested for timber, pulpwood, garden, and paper markets. However, genetic information and molecular markers were very scarce for this species. In this study, over 51 [...] Read more.

Japanese red pine (Pinus densiflora) is extensively cultivated in Japan, Korea, China, and Russia and is harvested for timber, pulpwood, garden, and paper markets. However, genetic information and molecular markers were very scarce for this species. In this study, over 51 million sequencing clean reads from P. densiflora mRNA were produced using Illumina paired-end sequencing technology. It yielded 83,913 unigenes with a mean length of 751 bp, of which 54,530 (64.98%) unigenes showed similarity to sequences in the NCBI database. Among which the best matches in the NCBI Nr database were Picea sitchensis (41.60%), Amborella trichopoda (9.83%), and Pinus taeda (4.15%). A total of 1953 putative microsatellites were identified in 1784 unigenes using MISA (MicroSAtellite) software, of which the tri-nucleotide repeats were most abundant (50.18%) and 629 EST-SSR (expressed sequence tag- simple sequence repeats) primer pairs were successfully designed. Among 20 EST-SSR primer pairs randomly chosen, 17 markers yielded amplification products of the expected size in P. densiflora. Our results will provide a valuable resource for gene-function analysis, germplasm identification, molecular marker-assisted breeding and resistance-related gene(s) mapping for pine for P. densiflora. Full article

(This article belongs to the Special Issue Plant Molecular Biology)

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Diversity and Inheritance of Intergenic Spacer Sequences of 45S Ribosomal DNA among Accessions of Brassica oleracea L. var. capitata

by Kiwoung Yang, Arif Hasan Khan Robin, Go-Eun Yi, Jonghoon Lee, Mi-Young Chung, Tae-Jin Yang and Ill-Sup Nou

Int. J. Mol. Sci. 2015, 16(12), 28783-28799; https://doi.org/10.3390/ijms161226125 - 3 Dec 2015

Cited by 12 | Viewed by 10387

Abstract

Ribosomal DNA (rDNA) of plants is present in high copy number and shows variation between and within species in the length of the intergenic spacer (IGS). The 45S rDNA of flowering plants includes the 5.8S, 18S and 25S rDNA genes, the internal transcribed [...] Read more.

Ribosomal DNA (rDNA) of plants is present in high copy number and shows variation between and within species in the length of the intergenic spacer (IGS). The 45S rDNA of flowering plants includes the 5.8S, 18S and 25S rDNA genes, the internal transcribed spacer (ITS1 and ITS2), and the intergenic spacer 45S-IGS (25S-18S). This study identified six different types of 45S-IGS, A to F, which at 363 bp, 1121 bp, 1717 bp, 1969 bp, 2036 bp and 2111 bp in length, respectively, were much shorter than the reported reference IGS sequences in B. oleracea var. alboglabra. The shortest two IGS types, A and B, lacked the transcription initiation site, non-transcribed spacer, and external transcribed spacer. Functional behavior of those two IGS types in relation to rRNA synthesis is a subject of further investigation. The other four IGSs had subtle variations in the transcription termination site, guanine-cytosine (GC) content, and number of tandem repeats, but the external transcribed spacers of these four IGSs were quite similar in length. The 45S IGSs were found to follow Mendelian inheritance in a population of 15 F₁s and their 30 inbred parental lines, which suggests that these sequences could be useful for development of new breeding tools. In addition, this study represents the first report of intra-specific (within subspecies) variation of the 45S IGS in B. oleracea. Full article

(This article belongs to the Special Issue Plant Molecular Biology)

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Omics-Based Comparative Transcriptional Profiling of Two Contrasting Rice Genotypes during Early Infestation by Small Brown Planthopper

by Weilin Zhang, Ling Yang, Mei Li, Bojun Ma, Chengqi Yan and Jianping Chen

Int. J. Mol. Sci. 2015, 16(12), 28746-28764; https://doi.org/10.3390/ijms161226128 - 3 Dec 2015

Cited by 12 | Viewed by 6246

Abstract

The small brown planthopper (SBPH) is one of the destructive pests of rice. Although different biochemical pathways that are involved in rice responding to planthopper infestation have been documented, it is unclear which individual metabolic pathways are responsive to planthopper infestation. In this [...] Read more.

The small brown planthopper (SBPH) is one of the destructive pests of rice. Although different biochemical pathways that are involved in rice responding to planthopper infestation have been documented, it is unclear which individual metabolic pathways are responsive to planthopper infestation. In this study, an omics-based comparative transcriptional profiling of two contrasting rice genotypes, an SBPH-resistant and an SBPH-susceptible rice line, was assessed for rice individual metabolic pathways responsive to SBPH infestation. When exposed to SBPH, 166 metabolic pathways were differentially regulated; of these, more than one-third of metabolic pathways displayed similar change patterns between these two contrasting rice genotypes; the difference of change pattern between these two contrasting rice genotypes mostly lies in biosynthetic pathways and the obvious difference of change pattern lies in energy metabolism pathways. Combining the Pathway Tools Omics Viewer with the web tool Venn, 21 and 6 metabolic pathways which potentially associated with SBPH resistance and susceptibility, respectively were identified. This study presents an omics-based comparative transcriptional profiling of SBPH-resistant and SBPH-susceptible rice plants during early infestation by SBPH, which will be very informative in studying rice-insect interaction. The results will provide insight into how rice plants respond to early infestation by SBPH from the biochemical pathways perspective. Full article

(This article belongs to the Special Issue Molecular Research in Plant Secondary Metabolism 2015)

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Transcriptome Profiling of Louisiana iris Root and Identification of Genes Involved in Lead-Stress Response

by Songqing Tian, Chunsun Gu, Liangqin Liu, Xudong Zhu, Yanhai Zhao and Suzhen Huang

Int. J. Mol. Sci. 2015, 16(12), 28087-28097; https://doi.org/10.3390/ijms161226084 - 25 Nov 2015

Cited by 25 | Viewed by 6878

Abstract

Louisiana iris is tolerant to and accumulates the heavy metal lead (Pb). However, there is limited knowledge of the molecular mechanisms behind this feature. We describe the transcriptome of Louisiana iris using Illumina sequencing technology. The root transcriptome of Louisiana iris under control [...] Read more.

Louisiana iris is tolerant to and accumulates the heavy metal lead (Pb). However, there is limited knowledge of the molecular mechanisms behind this feature. We describe the transcriptome of Louisiana iris using Illumina sequencing technology. The root transcriptome of Louisiana iris under control and Pb-stress conditions was sequenced. Overall, 525,498 transcripts representing 313,958 unigenes were assembled using the clean raw reads. Among them, 43,015 unigenes were annotated and their functions classified using the euKaryotic Orthologous Groups (KOG) database. They were divided into 25 molecular families. In the Gene Ontology (GO) database, 50,174 unigenes were categorized into three GO trees (molecular function, cellular component and biological process). After analysis of differentially expressed genes, some Pb-stress-related genes were selected, including biosynthesis genes of chelating compounds, metal transporters, transcription factors and antioxidant-related genes. This study not only lays a foundation for further studies on differential genes under Pb stress, but also facilitates the molecular breeding of Louisiana iris. Full article

(This article belongs to the Special Issue Effects of Herbicides and Heavy Metals to the Structure and Function of Plant Cells)

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Genotypic Variation under Fe Deficiency Results in Rapid Changes in Protein Expressions and Genes Involved in Fe Metabolism and Antioxidant Mechanisms in Tomato Seedlings (Solanum lycopersicum L.)

by Sowbiya Muneer and Byoung Ryong Jeong

Int. J. Mol. Sci. 2015, 16(12), 28022-28037; https://doi.org/10.3390/ijms161226086 - 25 Nov 2015

Cited by 2 | Viewed by 6334

Abstract

To investigate Fe deficiency tolerance in tomato cultivars, quantification of proteins and genes involved in Fe metabolism and antioxidant mechanisms were performed in “Roggusanmaru” and “Super Doterang”. Fe deficiency (Moderate, low and –Fe) significantly decreased the biomass, total, and apoplastic Fe concentration of [...] Read more.

To investigate Fe deficiency tolerance in tomato cultivars, quantification of proteins and genes involved in Fe metabolism and antioxidant mechanisms were performed in “Roggusanmaru” and “Super Doterang”. Fe deficiency (Moderate, low and –Fe) significantly decreased the biomass, total, and apoplastic Fe concentration of “Roggusanmaru”, while a slight variation was observed in “Super Doterang” cultivar. The quantity of important photosynthetic pigments such as total chlorophyll and carotenoid contents significantly decreased in “Roggusanmaru” than “Super Doterang” cultivar. The total protein profile in leaves and roots determines that “Super Doterang” exhibited an optimal tolerance to Fe deficiency compared to “Roggusanmaru” cultivar. A reduction in expression of PSI (photosystem I), PSII (photosystem II) super-complexes and related thylakoid protein contents were detected in “Roggusanmaru” than “Super Doterang” cultivar. Moreover, the relative gene expression of SlPSI and SlPSII were well maintained in “Super Doterang” than “Roggusanmaru” cultivar. The relative expression of genes involved in Fe-transport (SlIRT1 and SlIRT2) and Fe(III) chelates reductase oxidase (SlFRO1) were relatively reduced in “Roggusanmaru”, while increased in “Super Doterang” cultivar under Fe deficient conditions. The H⁺-ATPase relative gene expression (SlAHA1) in roots were maintained in “Super Doterang” compared to “Roggusanmaru”. Furthermore, the gene expressions involved in antioxidant defense mechanisms (SlSOD, SlAPX and SlCAT) in leaves and roots showed that these genes were highly increased in “Super Doterang”, whereas decreased in “Roggusanmaru” cultivar under Fe deficiency. The present study suggested that “Super Doterang” is better tomato cultivar than “Roggusanmaru” for calcareous soils. Full article

(This article belongs to the Special Issue Plant Molecular Biology)

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A PPO Promoter from Betalain-Producing Red Swiss Chard, Directs Petiole- and Root-Preferential Expression of Foreign Gene in Anthocyanins-Producing Plants

by Zhi-Hai Yu, Ya-Nan Han and Xing-Guo Xiao

Int. J. Mol. Sci. 2015, 16(11), 27032-27043; https://doi.org/10.3390/ijms161126011 - 12 Nov 2015

Cited by 15 | Viewed by 6579

Abstract

A 1670 bp 5′-flanking region of the polyphenol oxidase (PPO) gene was isolated from red Swiss chard, a betalain-producing plant. This region, named promoter BvcPPOP, and its 5′-truncated versions were fused with the GUS gene and introduced into Arabidopsis, an anthocyanins-producing plant. [...] Read more.

A 1670 bp 5′-flanking region of the polyphenol oxidase (PPO) gene was isolated from red Swiss chard, a betalain-producing plant. This region, named promoter BvcPPOP, and its 5′-truncated versions were fused with the GUS gene and introduced into Arabidopsis, an anthocyanins-producing plant. GUS histochemical staining and quantitative analysis of transgenic plants at the vegetative and reproductive stages showed that BvcPPOP could direct GUS gene expression in vegetative organs with root- and petiole-preference, but not in reproductive organs including inflorescences shoot, inflorescences leaf, flower, pod and seed. This promoter was regulated by developmental stages in its driving strength, but not in expression pattern. It was also regulated by the abiotic stressors tested, positively by salicylic acid (SA) and methyl jasmonate (MeJA) but negatively by abscisic acid (ABA), gibberellin (GA), NaCl and OH⁻. Its four 5′-truncated versions varied in the driving strength, but not obviously in expression pattern, and even the shortest version (−225 to +22) retained the root- and petiole- preference. This promoter is, to our knowledge, the first PPO promoter cloned and functionally elucidated from the betalain-producing plant, and thus provides not only a useful tool for expressing gene(s) of agricultural interest in vegetative organs, but also a clue to clarify the function of metabolism-specific PPO in betalain biosynthesis. Full article

(This article belongs to the Special Issue Plant Molecular Biology)

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Metabolic Profiling of Pyrrolizidine Alkaloids in Foliage of Two Echium spp. Invaders in Australia—A Case of Novel Weapons?

by Dominik Skoneczny, Paul A. Weston, Xiaocheng Zhu, Geoff M. Gurr, Ragan M. Callaway and Leslie A. Weston

Int. J. Mol. Sci. 2015, 16(11), 26721-26737; https://doi.org/10.3390/ijms161125979 - 6 Nov 2015

Cited by 32 | Viewed by 7785

Abstract

Metabolic profiling allows for simultaneous and rapid annotation of biochemically similar organismal metabolites. An effective platform for profiling of toxic pyrrolizidine alkaloids (PAs) and their N-oxides (PANOs) was developed using ultra high pressure liquid chromatography quadrupole time-of-flight (UHPLC-QTOF) mass spectrometry. Field-collected populations of [...] Read more.

Metabolic profiling allows for simultaneous and rapid annotation of biochemically similar organismal metabolites. An effective platform for profiling of toxic pyrrolizidine alkaloids (PAs) and their N-oxides (PANOs) was developed using ultra high pressure liquid chromatography quadrupole time-of-flight (UHPLC-QTOF) mass spectrometry. Field-collected populations of invasive Australian weeds, Echium plantagineum and E. vulgare were raised under controlled glasshouse conditions and surveyed for the presence of related PAs and PANOs in leaf tissues at various growth stages. Echium plantagineum possessed numerous related and abundant PANOs (>17) by seven days following seed germination, and these were also observed in rosette and flowering growth stages. In contrast, the less invasive E. vulgare accumulated significantly lower levels of most PANOs under identical glasshouse conditions. Several previously unreported PAs were also found at trace levels. Field-grown populations of both species were also evaluated for PA production and highly toxic echimidine N-oxide was amongst the most abundant PANOs in foliage of both species. PAs in field and glasshouse plants were more abundant in the more widely invasive species, E. plantagineum, and may provide competitive advantage by increasing the plant’s capacity to deter natural enemies in its invaded range through production of novel weapons. Full article

(This article belongs to the Special Issue Metabolomics in the Plant Sciences)

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CONSTITUTIVE PHOTOMORPHOGENIC 10 (COP10) Contributes to Floral Repression under Non-Inductive Short Days in Arabidopsis

by Min-Young Kang, Hye-Young Kwon, Na-Yun Kim, Yasuhito Sakuraba and Nam-Chon Paek

Int. J. Mol. Sci. 2015, 16(11), 26493-26505; https://doi.org/10.3390/ijms161125969 - 5 Nov 2015

Cited by 3 | Viewed by 8182

Abstract

In Arabidopsis, CONSTITUTIVE PHOTOMORPHOGENIC/DE-ETIOLATED/FUSCA (COP/DET/FUS) genes act in repression of photomorphogenesis in darkness, and recent reports revealed that some of these genes, such as COP1 and DET1, also have important roles in controlling flowering time and circadian rhythm. The [...] Read more.

In Arabidopsis, CONSTITUTIVE PHOTOMORPHOGENIC/DE-ETIOLATED/FUSCA (COP/DET/FUS) genes act in repression of photomorphogenesis in darkness, and recent reports revealed that some of these genes, such as COP1 and DET1, also have important roles in controlling flowering time and circadian rhythm. The COP/DET/FUS protein COP10 interacts with DET1 and DNA DAMAGE-BINDING PROTEIN 1 (DDB1) to form a CDD complex and represses photomorphogenesis in darkness. The cop10-4 mutants flower normally in inductive long days (LD) but early in non-inductive short days (SD) compared with wild type (WT); however, the role of COP10 remains unknown. Here, we investigate the role of COP10 in SD-dependent floral repression. Reverse transcription-quantitative PCR revealed that in SD, expression of the LD-dependent floral inducers GI, FKF1, and FT significantly increased in cop10-4 mutants, compared with WT. This suggests that COP10 mainly regulates FT expression in a CO-independent manner. We also show that COP10 interacts with GI in vitro and in vivo, suggesting that COP10 could also affect GI function at the posttranslational level. Moreover, FLC expression was repressed drastically in cop10-4 mutants and COP10 interacts with MULTICOPY SUPPRESSOR OF IRA1 4 (MSI4)/FVE (MSI4/FVE), which epigenetically inhibits FLC expression. These data suggest that COP10 contributes to delaying flowering in the photoperiod and autonomous pathways by downregulating FT expression under SD. Full article

(This article belongs to the Special Issue Plant Molecular Biology)

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ClRTL1 Encodes a Chinese Fir RNase III–Like Protein Involved in Regulating Shoot Branching

by Xia Li, Qian Su, Renhua Zheng, Guangxin Liu, Ye Lu, Liming Bian, Jinhui Chen and Jisen Shi

Int. J. Mol. Sci. 2015, 16(10), 25691-25710; https://doi.org/10.3390/ijms161025691 - 26 Oct 2015

Cited by 4 | Viewed by 6525

Abstract

Identification of genes controlling shoot branching is crucial for improving plant architecture and increasing crop yield or biomass. A branching mutant of Chinese fir named “Dugansha” (Cunninghamia lanceolata var. dugan.) has been isolated in our laboratory. We chose the cDNA-AFLP technique [...] Read more.

Identification of genes controlling shoot branching is crucial for improving plant architecture and increasing crop yield or biomass. A branching mutant of Chinese fir named “Dugansha” (Cunninghamia lanceolata var. dugan.) has been isolated in our laboratory. We chose the cDNA-AFLP technique and an effective strategy to screen genes that potentially regulate shoot branching in Chinese fir using this mutant. An RNase III-like1 cDNA fragment named ClRTL1 was identified as a potential positive regulator. To investigate the function of ClRTL1 in regulating shoot branching, we cloned the full-length cDNA sequence from C. lanceolata (Lamb.) Hook, deduced its secondary structure and function, and overexpressed the coding sequence in Arabidopsis. The ClRTL1 cDNA is 1045 bp and comprises an open reading frame of 705 bp. It encodes a protein of 235 amino acids. The deduced secondary structure of the ClRTL1 indicates that it is a mini-RNase III-like protein. The expression analysis and phenotypes of 35S: ClRTL1 in A. thaliana implies that ClRTL1 plays a role in promoting shoot branching in Chinese fir. Full article

(This article belongs to the Special Issue Molecular Research in Plant Secondary Metabolism 2015)

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De Novo Sequencing and Analysis of the Safflower Transcriptome to Discover Putative Genes Associated with Safflor Yellow in Carthamus tinctorius L.

by Xiuming Liu, Yuanyuan Dong, Na Yao, Yu Zhang, Nan Wang, Xiyan Cui, Xiaowei Li, Yanfang Wang, Fawei Wang, Jing Yang, Lili Guan, Linna Du, Haiyan Li and Xiaokun Li

Int. J. Mol. Sci. 2015, 16(10), 25657-25677; https://doi.org/10.3390/ijms161025657 - 26 Oct 2015

Cited by 26 | Viewed by 7932

Abstract

Safflower (Carthamus tinctorius L.), an important traditional Chinese medicine, is cultured widely for its pharmacological effects, but little is known regarding the genes related to the metabolic regulation of the safflower’s yellow pigment. To investigate genes related to safflor yellow biosynthesis, 454 [...] Read more.

Safflower (Carthamus tinctorius L.), an important traditional Chinese medicine, is cultured widely for its pharmacological effects, but little is known regarding the genes related to the metabolic regulation of the safflower’s yellow pigment. To investigate genes related to safflor yellow biosynthesis, 454 pyrosequencing of flower RNA at different developmental stages was performed, generating large databases.In this study, we analyzed 454 sequencing data from different flowering stages in safflower. In total, 1,151,324 raw reads and 1,140,594 clean reads were produced, which were assembled into 51,591 unigenes with an average length of 679 bp and a maximum length of 5109 bp. Among the unigenes, 40,139 were in the early group, 39,768 were obtained from the full group and 28,316 were detected in both samples. With the threshold of “log2 ratio ≥ 1”, there were 34,464 differentially expressed genes, of which 18,043 were up-regulated and 16,421 were down-regulated in the early flower library. Based on the annotations of the unigenes, 281 pathways were predicted. We selected 12 putative genes and analyzed their expression levels using quantitative real time-PCR. The results were consistent with the 454 sequencing results. In addition, the expression of chalcone synthase, chalcone isomerase and anthocyanidin synthase, which are involved in safflor yellow biosynthesis and safflower yellow pigment (SYP) content, were analyzed in different flowering periods, indicating that their expression levels were related to SYP synthesis. Moreover, to further confirm the results of the 454 pyrosequencing, full-length cDNA of chalcone isomerase (CHI) and anthocyanidin synthase (ANS) were cloned from safflower petal by RACE (Rapid-amplification of cDNA ends) method according to fragment of the transcriptome. Full article

(This article belongs to the Special Issue Plant Molecular Biology)

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6512 KiB

Open AccessArticle

Molecular Cloning and Characterization of DXS and DXR Genes in the Terpenoid Biosynthetic Pathway of Tripterygium wilfordii

by Yuru Tong, Ping Su, Yujun Zhao, Meng Zhang, Xiujuan Wang, Yujia Liu, Xianan Zhang, Wei Gao and Luqi Huang

Int. J. Mol. Sci. 2015, 16(10), 25516-25535; https://doi.org/10.3390/ijms161025516 - 23 Oct 2015

Cited by 62 | Viewed by 8258

Abstract

1-Deoxy-d-xylulose-5-phosphate synthase (DXS) and 1-deoxy-d-xylulose-5-phosphate reductoisomerase (DXR) genes are the key enzyme genes of terpenoid biosynthesis but still unknown in Tripterygium wilfordii Hook. f. Here, three full-length cDNA encoding DXS1, DXS2 and DXR were cloned from suspension cells of T. wilfordii with ORF [...] Read more.

1-Deoxy-d-xylulose-5-phosphate synthase (DXS) and 1-deoxy-d-xylulose-5-phosphate reductoisomerase (DXR) genes are the key enzyme genes of terpenoid biosynthesis but still unknown in Tripterygium wilfordii Hook. f. Here, three full-length cDNA encoding DXS1, DXS2 and DXR were cloned from suspension cells of T. wilfordii with ORF sizes of 2154 bp (TwDXS1, GenBank accession no.KM879187), 2148 bp (TwDXS2, GenBank accession no.KM879186), 1410 bp (TwDXR, GenBank accession no.KM879185). And, the TwDXS1, TwDXS2 and TwDXR were characterized by color complementation in lycopene accumulating strains of Escherichia coli, which indicated that they encoded functional proteins and promoted lycopene pathway flux. TwDXS1 and TwDXS2 are constitutively expressed in the roots, stems and leaves and the expression level showed an order of roots > stems > leaves. After the suspension cells were induced by methyl jasmonate, the mRNA expression level of TwDXS1, TwDXS2, and TwDXR increased, and triptophenolide was rapidly accumulated to 149.52 µg·g⁻¹, a 5.88-fold increase compared with the control. So the TwDXS1, TwDXS2, and TwDXR could be important genes involved in terpenoid biosynthesis in Tripterygium wilfordii Hook. f. Full article

(This article belongs to the Special Issue Molecular Research in Plant Secondary Metabolism 2015)

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2251 KiB

Open AccessArticle

Increased Uptake of Chelated Copper Ions by Lolium perenne Attributed to Amplified Membrane and Endodermal Damage

by Anthea Johnson and Naresh Singhal

Int. J. Mol. Sci. 2015, 16(10), 25264-25284; https://doi.org/10.3390/ijms161025264 - 23 Oct 2015

Cited by 7 | Viewed by 6586

Abstract

The contributions of mechanisms by which chelators influence metal translocation to plant shoot tissues are analyzed using a combination of numerical modelling and physical experiments. The model distinguishes between apoplastic and symplastic pathways of water and solute movement. It also includes the barrier [...] Read more.

The contributions of mechanisms by which chelators influence metal translocation to plant shoot tissues are analyzed using a combination of numerical modelling and physical experiments. The model distinguishes between apoplastic and symplastic pathways of water and solute movement. It also includes the barrier effects of the endodermis and plasma membrane. Simulations are used to assess transport pathways for free and chelated metals, identifying mechanisms involved in chelate-enhanced phytoextraction. Hypothesized transport mechanisms and parameters specific to amendment treatments are estimated, with simulated results compared to experimental data. Parameter values for each amendment treatment are estimated based on literature and experimental values, and used for model calibration and simulation of amendment influences on solute transport pathways and mechanisms. Modeling indicates that chelation alters the pathways for Cu transport. For free ions, Cu transport to leaf tissue can be described using purely apoplastic or transcellular pathways. For strong chelators (ethylenediaminetetraacetic acid (EDTA) and diethylenetriaminepentaacetic acid (DTPA)), transport by the purely apoplastic pathway is insufficient to represent measured Cu transport to leaf tissue. Consistent with experimental observations, increased membrane permeability is required for simulating translocation in EDTA and DTPA treatments. Increasing the membrane permeability is key to enhancing phytoextraction efficiency. Full article

(This article belongs to the Special Issue Effects of Herbicides and Heavy Metals to the Structure and Function of Plant Cells)

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