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Plants, Volume 8, Issue 2 (February 2019) – 25 articles

Cover Story (view full-size image): The pores of the sieve plate connect individual sieve elements to transport phloem sap from source to sink tissues. Like plasmodesmata, sieve pores are plasma-membrane-lined symplastic connections, but they have much larger dimensions. Sieve pores are major bottlenecks for hydraulic flow. Callose deposition, which is induced following damage to the plant, causes them to rapidly close. To reduce hydraulic resistance, sieve pore geometry has changed during evolution but is also adapted during the development of each individual plant. Although the anatomical changes during sieve pore formation were described decades ago, the molecular and genetic factors required for their formation are still unknown. In our review, we present the current knowledge on sieve pores and explore advances in cell biology that may help us to understand their formation. View this paper.
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Communication
Exposure to Ultraviolet (UV-C) Radiation Increases Germination Rate of Maize (Zea maize L.) and Sugar Beet (Beta vulgaris) Seeds
Plants 2019, 8(2), 49; https://doi.org/10.3390/plants8020049 - 24 Feb 2019
Cited by 10 | Viewed by 2457
Abstract
This study investigated the effect of ultraviolet (UV-C) radiation on the germination percentage, germination rate, radicle length, and plumule length of maize and sugar beet seeds. The experiment was implemented in six replicates of 30 seeds per replicate and in sterilized petri dishes [...] Read more.
This study investigated the effect of ultraviolet (UV-C) radiation on the germination percentage, germination rate, radicle length, and plumule length of maize and sugar beet seeds. The experiment was implemented in six replicates of 30 seeds per replicate and in sterilized petri dishes under laboratory conditions. Treatments included UV-C (254 nm) radiation exposure durations of 0 min (control), 30 min, 2 h, 4 h, 8 h, and 12 h. The UV-C radiation treatments did not significantly affect the germination percentage of the seeds (p < 0.05). However, the seeds germination rate was significantly affected by the UV-C radiation treatments. The treatments of 8 h and 12 h exposure duration led to the highest seed germination rates in maize and sugar beet, respectively. Lowest seed germination rates belonged to the controls. The radicle length of maize seeds was significantly affected by the UV-C radiation treatments, but the treatments did not significantly affect the radicle length of sugar beet seeds. The 12 h exposure to UV-C radiation treatment resulted in the largest radicle in maize, which was 2.08 cm larger than the radicle of the control seeds. The UV-C radiation treatments had a statistically significant effect on the plumule length of maize and sugar beet seeds. The treatment 8 h UV-C exposure duration led to the largest plumule in maize and sugar beet, which were 0.32 cm and 0.83 cm larger than the plumule of the control seeds, respectively. Breaking down the seed coat and increasing the temperature by UV-C radiation are potential reasons for the observed positive effects. Full article
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Review
S-Nitrosoglutathione Reductase—The Master Regulator of Protein S-Nitrosation in Plant NO Signaling
Plants 2019, 8(2), 48; https://doi.org/10.3390/plants8020048 - 21 Feb 2019
Cited by 43 | Viewed by 2818
Abstract
S-nitrosation has been recognized as an important mechanism of protein posttranslational regulations, based on the attachment of a nitroso group to cysteine thiols. Reversible S-nitrosation, similarly to other redox-base modifications of protein thiols, has a profound effect on protein structure and activity and [...] Read more.
S-nitrosation has been recognized as an important mechanism of protein posttranslational regulations, based on the attachment of a nitroso group to cysteine thiols. Reversible S-nitrosation, similarly to other redox-base modifications of protein thiols, has a profound effect on protein structure and activity and is considered as a convergence of signaling pathways of reactive nitrogen and oxygen species. In plant, S-nitrosation is involved in a wide array of cellular processes during normal development and stress responses. This review summarizes current knowledge on S-nitrosoglutathione reductase (GSNOR), a key enzyme which regulates intracellular levels of S-nitrosoglutathione (GSNO) and indirectly also of protein S-nitrosothiols. GSNOR functions are mediated by its enzymatic activity, which catalyzes irreversible GSNO conversion to oxidized glutathione within the cellular catabolism of nitric oxide. GSNOR is involved in the maintenance of balanced levels of reactive nitrogen species and in the control of cellular redox state. Multiple functions of GSNOR in plant development via NO-dependent and -independent signaling mechanisms and in plant defense responses to abiotic and biotic stress conditions have been uncovered. Extensive studies of plants with down- and upregulated GSNOR, together with application of transcriptomics and proteomics approaches, seem promising for new insights into plant S-nitrosothiol metabolism and its regulation. Full article
(This article belongs to the Special Issue Nitric Oxide Signaling in Plants)
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Article
Intrusive Growth of Phloem Fibers in Flax Stem: Integrated Analysis of miRNA and mRNA Expression Profiles
Plants 2019, 8(2), 47; https://doi.org/10.3390/plants8020047 - 19 Feb 2019
Cited by 11 | Viewed by 2490
Abstract
Phloem fibers are important elements of plant architecture and the target product of many fiber crops. A key stage in fiber development is intrusive elongation, the mechanisms of which are largely unknown. Integrated analysis of miRNA and mRNA expression profiles in intrusivelygrowing fibers [...] Read more.
Phloem fibers are important elements of plant architecture and the target product of many fiber crops. A key stage in fiber development is intrusive elongation, the mechanisms of which are largely unknown. Integrated analysis of miRNA and mRNA expression profiles in intrusivelygrowing fibers obtained by laser microdissection from flax (Linum usitatissimum L.) stem revealed all 124 known flax miRNA from 23 gene families and the potential targets of differentially expressed miRNAs. A comparison of the expression between phloem fibers at different developmental stages, and parenchyma and xylem tissues demonstrated that members of miR159, miR166, miR167, miR319, miR396 families were down-regulated in intrusively growing fibers. Some putative target genes of these miRNA families, such as those putatively encoding growth-regulating factors, an argonaute family protein, and a homeobox-leucine zipper family protein were up-regulated in elongating fibers. miR160, miR169, miR390, and miR394 showed increased expression. Changes in the expression levels of miRNAs and their target genes did not match expectations for the majority of predicted target genes. Taken together, poorly understood intrusive fiber elongation, the key process of phloem fiber development, was characterized from a miRNA-target point of view, giving new insights into its regulation. Full article
(This article belongs to the Special Issue Plant Phloem Development)
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Article
A Spotlight on Rad52 in Cyanidiophytina (Rhodophyta): A Relic in Algal Heritage
Plants 2019, 8(2), 46; https://doi.org/10.3390/plants8020046 - 19 Feb 2019
Cited by 4 | Viewed by 1464
Abstract
The RADiation sensitive52 (RAD52) protein catalyzes the pairing between two homologous DNA sequences’ double-strand break repair and meiotic recombination, mediating RAD51 loading onto single-stranded DNA ends, and initiating homologous recombination and catalyzing DNA annealing. This article reports the characterization of RAD52 homologs in [...] Read more.
The RADiation sensitive52 (RAD52) protein catalyzes the pairing between two homologous DNA sequences’ double-strand break repair and meiotic recombination, mediating RAD51 loading onto single-stranded DNA ends, and initiating homologous recombination and catalyzing DNA annealing. This article reports the characterization of RAD52 homologs in the thermo-acidophilic Cyanidiophyceae whose genomes have undergone extensive sequencing. Database mining, phylogenetic inference, prediction of protein structure and evaluation of gene expression were performed in order to determine the functionality of the RAD52 protein in Cyanidiophyceae. Its current function in Cyanidiophytina could be related to stress damage response for thriving in hot and acidic environments as well as to the genetic variability of these algae, in which, conversely to extant Rhodophyta, sexual mating was never observed. Full article
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Article
Effects of Nitrogen Dioxide on Biochemical Responses in 41 Garden Plants
Plants 2019, 8(2), 45; https://doi.org/10.3390/plants8020045 - 16 Feb 2019
Cited by 11 | Viewed by 2873
Abstract
Nitrogen dioxide (NO2) at a high concentration is among the most common and harmful air pollutants. The present study aimed to explore the physiological responses of plants exposed to NO2. A total of 41 plants were classified into 13 [...] Read more.
Nitrogen dioxide (NO2) at a high concentration is among the most common and harmful air pollutants. The present study aimed to explore the physiological responses of plants exposed to NO2. A total of 41 plants were classified into 13 functional groups according to the Angiosperm Phylogeny Group classification system. The plants were exposed to 6 μL/L NO2 in an open-top glass chamber. The physiological parameters (chlorophyll (Chl) content, peroxidase (POD) activity, and soluble protein and malondialdehyde (MDA) concentrations) and leaf mineral ion contents (nitrogen (N+), phosphorus (P+), potassium (K+), calcium (Ca2+), magnesium (Mg2+), manganese (Mn2+), and zinc (Zn2+)) of 41 garden plants were measured. After NO2 exposure, the plants were subsequently transferred to a natural environment for a 30-d recovery to determine whether they could recover naturally and resume normal growth. The results showed that NO2 polluted the plants and that NO2 exposure affected leaf Chl contents in most functional groups. Increases in both POD activity and soluble protein and MDA concentrations as well as changes in mineral ion concentrations could act as signals for inducing defense responses. Furthermore, antioxidant status played an important role in plant protection against NO2-induced oxidative damage. NO2 poses a pollution risk to plant systems, and antioxidant status plays an important role in plant protection against NO2-induced oxidative damage. In conditions of strong air pollution, more evergreen plants may be considered in landscape design, particularly in seasonal regions. The results of this study may provide useful data for the selection of landscaping plants in NO2 polluted areas. Full article
Article
Foliar Aspersion of Salicylic Acid Improves Phenolic and Flavonoid Compounds, and Also the Fruit Yield in Cucumber (Cucumis sativus L.)
Plants 2019, 8(2), 44; https://doi.org/10.3390/plants8020044 - 16 Feb 2019
Cited by 22 | Viewed by 1931
Abstract
The aim of this research is to evaluate the effect of foliar application of salicylic acid (SA) on the yield and phytochemical content in hydroponically grown cucumber (Cucumis sativus L.). (1) Background: The importance of Mexico’s cucumber production is based on its [...] Read more.
The aim of this research is to evaluate the effect of foliar application of salicylic acid (SA) on the yield and phytochemical content in hydroponically grown cucumber (Cucumis sativus L.). (1) Background: The importance of Mexico’s cucumber production is based on its cultivation in recent decades as one of the major winter crops; in addition, the production of vegetables under hydroponic systems has increased significantly during the last few years, with cucumber being one of the vegetables with a high economic potential. (2) Methods: A completely randomized experimental design with 15 repetitions was used. SA at five doses (0.075, 0.1, 0.15, 0.25, and 0.5 mM) and one control (distilled water) was sprinkled weekly on cucumber plants. The evaluated variables were yield (total fruit weight per plant), fruit parameters (length, size and firmness), and nutraceutical quality of cucumber. (3) Results: Low concentrations of SA improve the yield and high concentrations decrease it, but the nutraceutical quality of fruits is improved, as compared to the control treatment. (4) Conclusions: In order to obtain a higher content of bioactive compounds without affecting the yield and commercial quality of cucumber fruits, it is advisable to use the average concentration (0.15 mM) of SA. Full article
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Article
Morpho-Physiological and Proteomic Analyses of Eucalyptus camaldulensis as a Bioremediator in Copper-Polluted Soil in Saudi Arabia
Plants 2019, 8(2), 43; https://doi.org/10.3390/plants8020043 - 15 Feb 2019
Cited by 7 | Viewed by 1801 | Retraction
Abstract
The present investigation aimed to assess the impact of copper (Cu) stress on the physiological and proteomic behavior of Eucalyptus camaldulensis. E. camaldulensis is likely a potential phytoremediator in areas vulnerable to Cu contamination, such as the industrial areas of Riyadh. To realize [...] Read more.
The present investigation aimed to assess the impact of copper (Cu) stress on the physiological and proteomic behavior of Eucalyptus camaldulensis. E. camaldulensis is likely a potential phytoremediator in areas vulnerable to Cu contamination, such as the industrial areas of Riyadh. To realize this objective, young seedlings of E. camaldulensis were potted in an open area with soil comprised of clay and sand. Different doses of Cu (30, 50, and 100 µM) were applied to the plants as CuSO4·5H2O for 6 weeks. Plant growth was monitored during the Cu exposure period, and morphological and physiological indicators were measured once a week to determine the growth rates. A proteomics study was also conducted to find out the influence of Cu stress on proteins. Our results showed that growth was negatively affected by Cu treatment, particularly at the highest concentrations. Moreover, using a proteomic analysis showed 26 targets involved in protein expression. Elevated levels of Cu increased the expression of 11 proteins and decreased the expression of 15 proteins. Changes were detected in proteins involved in photosynthesis, translation, transcription, metabolism, and antioxidant enzymes. Our findings provided insights into the molecular mechanisms related to Cu stress, in addition to its influence on the morphological and physiological attributes of E. camaldulensis seedlings. This investigation aimed to characterize the mechanism behind the impact of Cu stress on the plant. Full article
(This article belongs to the Section Plant Ecology)
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Article
Diversity and Functionality of Culturable Endophytic Bacterial Communities in Chickpea Plants
Plants 2019, 8(2), 42; https://doi.org/10.3390/plants8020042 - 14 Feb 2019
Cited by 29 | Viewed by 3114
Abstract
The aims of this study were to isolate, identify and characterize culturable endophytic bacteria from chickpea (Cicer arietinum L.) roots grown in different soils. In addition, the effects of rhizobial inoculation, soil and stress on the functionality of those culturable endophytic bacterial [...] Read more.
The aims of this study were to isolate, identify and characterize culturable endophytic bacteria from chickpea (Cicer arietinum L.) roots grown in different soils. In addition, the effects of rhizobial inoculation, soil and stress on the functionality of those culturable endophytic bacterial communities were also investigated. Phylogenetic analysis based on partial 16S rRNA gene sequences revealed that the endophytic bacteria isolated in this work belong to the phyla Proteobacteria, Firmicutes and Actinobacteria, with Enterobacter and Pseudomonas being the most frequently observed genera. Production of indoleacetic acid and ammonia were the most widespread plant growth-promoting features, while antifungal activity was relatively rare among the isolates. Despite the fact that the majority of bacterial endophytes were salt- and Mn-tolerant, the isolates obtained from soil with Mn toxicity were generally more Mn-tolerant than those obtained from the same soil amended with dolomitic limestone. Several associations between an isolate’s genus and specific plant growth-promoting mechanisms were observed. The data suggest that soil strongly impacts the Mn tolerance of endophytic bacterial communities present in chickpea roots while rhizobial inoculation induces significant changes in terms of isolates’ plant growth-promoting abilities. In addition, this study also revealed chickpea-associated endophytic bacteria that could be exploited as sources with potential application in agriculture. Full article
(This article belongs to the Section Plant Protection and Biotic Interactions)
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Review
Nitric Oxide: Its Generation and Interactions with Other Reactive Signaling Compounds
Plants 2019, 8(2), 41; https://doi.org/10.3390/plants8020041 - 12 Feb 2019
Cited by 47 | Viewed by 3255
Abstract
Nitric oxide (NO) is an immensely important signaling molecule in animals and plants. It is involved in plant reproduction, development, key physiological responses such as stomatal closure, and cell death. One of the controversies of NO metabolism in plants is the identification of [...] Read more.
Nitric oxide (NO) is an immensely important signaling molecule in animals and plants. It is involved in plant reproduction, development, key physiological responses such as stomatal closure, and cell death. One of the controversies of NO metabolism in plants is the identification of enzymatic sources. Although there is little doubt that nitrate reductase (NR) is involved, the identification of a nitric oxide synthase (NOS)-like enzyme remains elusive, and it is becoming increasingly clear that such a protein does not exist in higher plants, even though homologues have been found in algae. Downstream from its production, NO can have several potential actions, but none of these will be in isolation from other reactive signaling molecules which have similar chemistry to NO. Therefore, NO metabolism will take place in an environment containing reactive oxygen species (ROS), hydrogen sulfide (H2S), glutathione, other antioxidants and within a reducing redox state. Direct reactions with NO are likely to produce new signaling molecules such as peroxynitrite and nitrosothiols, and it is probable that chemical competitions will exist which will determine the ultimate end result of signaling responses. How NO is generated in plants cells and how NO fits into this complex cellular environment needs to be understood. Full article
(This article belongs to the Special Issue Nitric Oxide Signaling in Plants)
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Review
Traditional Medicine Plant, Onopordum acanthium L. (Asteraceae): Chemical Composition and Pharmacological Research
Plants 2019, 8(2), 40; https://doi.org/10.3390/plants8020040 - 12 Feb 2019
Cited by 7 | Viewed by 2640
Abstract
For many years, plants have been used in the traditional medicine of different cultures. The biennial plant of the family Asteraceae, Onopordum acanthium L., also known as Scotch thistle, is used in traditional medicine as an anti-inflammatory, antitumor, and cardiotonic agent. The plant [...] Read more.
For many years, plants have been used in the traditional medicine of different cultures. The biennial plant of the family Asteraceae, Onopordum acanthium L., also known as Scotch thistle, is used in traditional medicine as an anti-inflammatory, antitumor, and cardiotonic agent. The plant is widespread in the world; it grows in Europe and Asia and was introduced to America and Australia. Stems and buds of the first-year plant are used in cooking as an analogue of artichoke in European cuisine. Additionally, inflorescences contain a complex of proteolytic enzymes “onopordosin”, which may be used as a milk-clotting agent in the dairy industry. The chemical composition of the aerial part and roots of O. acanthium is represented by flavonoids, phenylpropanoids, lignans, triterpenoids, sesquiterpene lactones, and sterols. The anti-inflammatory, antiproliferative, and cardiotonic properties of the plant have been confirmed by pharmacological experiments with extracts and individual compounds using in silico, in vitro, and in vivo methods. This work is a review of information on the chemical composition and pharmacological studies of O. acanthium as a promising medicinal plant. Full article
(This article belongs to the Special Issue Plant Phytochemicals on Crop Protection and Biotechnology)
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Article
PbCOP1.1 Contributes to the Negative Regulation of Anthocyanin Biosynthesis in Pear
Plants 2019, 8(2), 39; https://doi.org/10.3390/plants8020039 - 12 Feb 2019
Cited by 16 | Viewed by 1656
Abstract
The synthesis of anthocyanin in pear (Pyrus bretschneideri) fruit is regulated by light. However, little is known about the molecular mechanisms of pear fruit coloring mediated by upstream light-signaling regulators. Here, the photoresponse factors CONSTITUTIVE PHOTOMORPHOGENIC (COP) 1.1 and 1.2 were [...] Read more.
The synthesis of anthocyanin in pear (Pyrus bretschneideri) fruit is regulated by light. However, little is known about the molecular mechanisms of pear fruit coloring mediated by upstream light-signaling regulators. Here, the photoresponse factors CONSTITUTIVE PHOTOMORPHOGENIC (COP) 1.1 and 1.2 were cloned from ‘Red Zaosu’ peel to study their functions in pear fruit coloring. The overexpression vectors pBI121-PbCOP1.1 and pBI121-PbCOP1.2 were constructed to analyze their effects on anthocyanin synthesis in pear fruit. A protein sequence alignment and phylogenetic tree analysis revealed that PbCOP1 proteins are highly homologous with those of other species. An analysis of tissue differential expression showed that the greatest expression levels of PbCOP1s occurred in the leaves. Their expression levels increased in the leaves during development, when the leaves changed from red to green. The overexpression of PbCOP1s in the peel resulted in reduced anthocyanin synthesis at the injection sites. A quantitative PCR analysis of the injection sites showed that PbCOP1.1 significantly inhibited the expression of the anthocyanin synthesis-related genes CHI, DFR, UFGT2, bHLH3, HY5 and GST. Based on the above results, we hypothesize that PbCOP1.1 is an anthocyanin synthetic inhibitory factor of pear coloration. Full article
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Review
Using Morphogenic Genes to Improve Recovery and Regeneration of Transgenic Plants
Plants 2019, 8(2), 38; https://doi.org/10.3390/plants8020038 - 11 Feb 2019
Cited by 42 | Viewed by 3741
Abstract
Efficient transformation of numerous important crops remains a challenge, due predominantly to our inability to stimulate growth of transgenic cells capable of producing plants. For years, this difficulty has been partially addressed by tissue culture strategies that improve regeneration either through somatic embryogenesis [...] Read more.
Efficient transformation of numerous important crops remains a challenge, due predominantly to our inability to stimulate growth of transgenic cells capable of producing plants. For years, this difficulty has been partially addressed by tissue culture strategies that improve regeneration either through somatic embryogenesis or meristem formation. Identification of genes involved in these developmental processes, designated here as morphogenic genes, provides useful tools in transformation research. In species from eudicots and cereals to gymnosperms, ectopic overexpression of genes involved in either embryo or meristem development has been used to stimulate growth of transgenic plants. However, many of these genes produce pleiotropic deleterious phenotypes. To mitigate this, research has been focusing on ways to take advantage of growth-stimulating morphogenic genes while later restricting or eliminating their expression in the plant. Methods of controlling ectopic overexpression include the use of transient expression, inducible promoters, tissue-specific promoters, and excision of the morphogenic genes. These methods of controlling morphogenic gene expression have been demonstrated in a variety of important crops. Here, we provide a review that highlights how ectopic overexpression of genes involved in morphogenesis has been used to improve transformation efficiencies, which is facilitating transformation of numerous recalcitrant crops. The use of morphogenic genes may help to alleviate one of the bottlenecks currently slowing progress in plant genome modification. Full article
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Review
Impact of Nitric Oxide (NO) on the ROS Metabolism of Peroxisomes
Plants 2019, 8(2), 37; https://doi.org/10.3390/plants8020037 - 10 Feb 2019
Cited by 27 | Viewed by 3076
Abstract
Nitric oxide (NO) is a gaseous free radical endogenously generated in plant cells. Peroxisomes are cell organelles characterized by an active metabolism of reactive oxygen species (ROS) and are also one of the main cellular sites of NO production in higher plants. In [...] Read more.
Nitric oxide (NO) is a gaseous free radical endogenously generated in plant cells. Peroxisomes are cell organelles characterized by an active metabolism of reactive oxygen species (ROS) and are also one of the main cellular sites of NO production in higher plants. In this mini-review, an updated and comprehensive overview is presented of the evidence available demonstrating that plant peroxisomes have the capacity to generate NO, and how this molecule and its derived products, peroxynitrite (ONOO) and S-nitrosoglutathione (GSNO), can modulate the ROS metabolism of peroxisomes, mainly throughout protein posttranslational modifications (PTMs), including S-nitrosation and tyrosine nitration. Several peroxisomal antioxidant enzymes, such as catalase (CAT), copper-zinc superoxide dismutase (CuZnSOD), and monodehydroascorbate reductase (MDAR), have been demonstrated to be targets of NO-mediated PTMs. Accordingly, plant peroxisomes can be considered as a good example of the interconnection existing between ROS and reactive nitrogen species (RNS), where NO exerts a regulatory function of ROS metabolism acting upstream of H2O2. Full article
(This article belongs to the Special Issue Nitric Oxide Signaling in Plants)
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Article
The Power of Genomic in situ Hybridization (GISH) in Interspecific Breeding of Bulb Onion (Allium cepa L.) Resistant to Downy Mildew (Peronospora destructor [Berk.] Casp.)
Plants 2019, 8(2), 36; https://doi.org/10.3390/plants8020036 - 04 Feb 2019
Cited by 6 | Viewed by 3430
Abstract
We exploited the advantages of genomic in situ hybridization (GISH) to monitor the introgression process at the chromosome level using a simple and robust molecular marker in the interspecific breeding of bulb onion (Allium cepa L.) that is resistant to downy mildew. [...] Read more.
We exploited the advantages of genomic in situ hybridization (GISH) to monitor the introgression process at the chromosome level using a simple and robust molecular marker in the interspecific breeding of bulb onion (Allium cepa L.) that is resistant to downy mildew. Downy mildew (Peronospora destructor [Berk.] Casp.) is the most destructive fungal disease for bulb onions. With the application of genomic in situ hybridization (GISH) and previously developed DMR1 marker, homozygous introgression lines that are resistant to downy mildew were successfully produced in a rather short breeding time. Considering that the bulb onion is a biennial plant, it took seven years from the F1 hybrid production to the creation of S2BC2 homozygous lines that are resistant to downy mildew. Using GISH, it was shown that three progeny plants of S2BC2 possessed an A. roylei homozygous fragment in the distal region of the long arm of chromosomes 3 in an A. cepa genetic background. Previously, it was hypothesized that a lethal gene(s) was linked to the downy mildew resistance gene. With the molecular cytogenetic approach, we physically mapped more precisely the lethal gene(s) using the homozygous introgression lines that differed in the size of the A. roylei fragments on chromosome 3. Full article
(This article belongs to the Section Plant Genetics, Genomics and Biotechnology)
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Article
Plant Growth Regulators Improve the Production of Volatile Organic Compounds in Two Rose Varieties
Plants 2019, 8(2), 35; https://doi.org/10.3390/plants8020035 - 31 Jan 2019
Cited by 8 | Viewed by 2862
Abstract
The study focused on the influence of the plant growth regulators (PGRs) benzyladenine (BA) and naphthalene acetic acid (NAA) on the production of volatile organic compounds (VOCs) from the flowers of two modern rose varieties, Hybrid Tea and Floribunda. Thirty-six plants of Hybrid [...] Read more.
The study focused on the influence of the plant growth regulators (PGRs) benzyladenine (BA) and naphthalene acetic acid (NAA) on the production of volatile organic compounds (VOCs) from the flowers of two modern rose varieties, Hybrid Tea and Floribunda. Thirty-six plants of Hybrid Tea and Floribunda were tested. Benzyladenine and naphthalene acetic acid were applied at 0, 100 and 200 mg/L to both rose varieties. Gas chromatography, coupled with flame ionization detection and mass spectrometry, was used to analyze and identify the volatile organic compounds from the flowers. A three-phase fiber 50/30 µm divinylbenzene/carboxen/polydimethylsiloxane was used to capture VOCs, at 2, 4 and 8 weeks, and 4 weeks was selected as it had the highest peak area. In total, 81 and 76 VOCs were detected after treatment of both rose varieties with BA and NAA, respectively. In addition, 20 compounds, which had significant differences between different treatments, were identified from both rose varieties. The majority of VOCs were extracted after the application of 200 mg (BA and NAA) /L of formulation, and four important compounds, cis-muurola-4(141)5-diene, y-candinene, y-muurolene and prenyl acetate, increased significantly compared to the controls. These compounds are commercially important aroma chemicals. This study used the rapid and solvent-free SPME method to show that BA and NAA treatments can result in significant VOC production in the flowers of two rose varieties, enhancing the aromatic value of the flowers. This method has the potential to be applied to other valuable aromatic floricultural plant species. Full article
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Review
Impact of Climate Change on Crops Adaptation and Strategies to Tackle Its Outcome: A Review
Plants 2019, 8(2), 34; https://doi.org/10.3390/plants8020034 - 30 Jan 2019
Cited by 330 | Viewed by 22130
Abstract
Agriculture and climate change are internally correlated with each other in various aspects, as climate change is the main cause of biotic and abiotic stresses, which have adverse effects on the agriculture of a region. The land and its agriculture are being affected [...] Read more.
Agriculture and climate change are internally correlated with each other in various aspects, as climate change is the main cause of biotic and abiotic stresses, which have adverse effects on the agriculture of a region. The land and its agriculture are being affected by climate changes in different ways, e.g., variations in annual rainfall, average temperature, heat waves, modifications in weeds, pests or microbes, global change of atmospheric CO2 or ozone level, and fluctuations in sea level. The threat of varying global climate has greatly driven the attention of scientists, as these variations are imparting negative impact on global crop production and compromising food security worldwide. According to some predicted reports, agriculture is considered the most endangered activity adversely affected by climate changes. To date, food security and ecosystem resilience are the most concerning subjects worldwide. Climate-smart agriculture is the only way to lower the negative impact of climate variations on crop adaptation, before it might affect global crop production drastically. In this review paper, we summarize the causes of climate change, stresses produced due to climate change, impacts on crops, modern breeding technologies, and biotechnological strategies to cope with climate change, in order to develop climate resilient crops. Revolutions in genetic engineering techniques can also aid in overcoming food security issues against extreme environmental conditions, by producing transgenic plants. Full article
(This article belongs to the Special Issue Plants Reacts to the Changing Environment)
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Article
Meta-Analysis of Quantitative Trait Loci Associated with Seedling-Stage Salt Tolerance in Rice (Oryza sativa L.)
Plants 2019, 8(2), 33; https://doi.org/10.3390/plants8020033 - 29 Jan 2019
Cited by 30 | Viewed by 3914
Abstract
Soil and water salinity is one of the major abiotic stresses that reduce growth and productivity in major food crops including rice. The lack of congruence of salt tolerance quantitative trait loci (QTLs) in multiple genetic backgrounds and multiple environments is a major [...] Read more.
Soil and water salinity is one of the major abiotic stresses that reduce growth and productivity in major food crops including rice. The lack of congruence of salt tolerance quantitative trait loci (QTLs) in multiple genetic backgrounds and multiple environments is a major hindrance for undertaking marker-assisted selection (MAS). A genome-wide meta-analysis of QTLs controlling seedling-stage salt tolerance was conducted in rice using QTL information from 12 studies. Using a consensus map, 11 meta-QTLs for three traits with smaller confidence intervals were localized on chromosomes 1 and 2. The phenotypic variance of 3 meta-QTLs was ≥20%. Based on phenotyping of 56 diverse genotypes and breeding lines, six salt-tolerant genotypes (Bharathy, I Kung Ban 4-2 Mutant, Langmanbi, Fatehpur 3, CT-329, and IARI 5823) were identified. The perusal of the meta-QTL regions revealed several candidate genes associated with salt-tolerance attributes. The lack of association between meta-QTL linked markers and the level of salt tolerance could be due to the low resolution of meta-QTL regions and the genetic complexity of salt tolerance. The meta-QTLs identified in this study will be useful not only for MAS and pyramiding, but will also accelerate the fine mapping and cloning of candidate genes associated with salt-tolerance mechanisms in rice. Full article
(This article belongs to the Section Plant Genetics, Genomics and Biotechnology)
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Review
Taxonomical and Phytochemical Characterisation of 10 Stachys Taxa Recorded in the Balkan Peninsula Flora: A Review
Plants 2019, 8(2), 32; https://doi.org/10.3390/plants8020032 - 29 Jan 2019
Cited by 5 | Viewed by 1561
Abstract
The genus Stachys is one of the largest genera of the Lamiaceae, and it comprises about 300 species. Some species are highly polymorphic, with a number of infraspecific taxa. The aim of the present review is to summarise the available knowledge on 10 [...] Read more.
The genus Stachys is one of the largest genera of the Lamiaceae, and it comprises about 300 species. Some species are highly polymorphic, with a number of infraspecific taxa. The aim of the present review is to summarise the available knowledge on 10 taxa belonging to the Balkan Peninsula flora (S. alpina L., S. germanica L., S. menthifolia Vis., S. obliqua Waldst. Et Kit., S. officinalis (L.) Trevis., S. palustris L., S. recta L. subsp. recta, S. recta L. subsp. subcrenata (Vis.) Briq., S. salviifolia Ten., and S. sylvatica L.) in order to enable insight into the identified biologically active substances and their possible application in intrageneric differentiation. Full article
(This article belongs to the Special Issue Lamiaceae Species: Biology, Ecology and Practical Uses)
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Review
Tolerance of Iron-Deficient and -Toxic Soil Conditions in Rice
Plants 2019, 8(2), 31; https://doi.org/10.3390/plants8020031 - 28 Jan 2019
Cited by 58 | Viewed by 4742
Abstract
Iron (Fe) deficiency and toxicity are the most widely prevalent soil-related micronutrient disorders in rice (Oryza sativa L.). Progress in rice cultivars with improved tolerance has been hampered by a poor understanding of Fe availability in the soil, the transportation mechanism, and [...] Read more.
Iron (Fe) deficiency and toxicity are the most widely prevalent soil-related micronutrient disorders in rice (Oryza sativa L.). Progress in rice cultivars with improved tolerance has been hampered by a poor understanding of Fe availability in the soil, the transportation mechanism, and associated genetic factors for the tolerance of Fe toxicity soil (FTS) or Fe deficiency soil (FDS) conditions. In the past, through conventional breeding approaches, rice varieties were developed especially suitable for low- and high-pH soils, which indirectly helped the varieties to tolerate FTS and FDS conditions. Rice-Fe interactions in the external environment of soil, internal homeostasis, and transportation have been studied extensively in the past few decades. However, the molecular and physiological mechanisms of Fe uptake and transport need to be characterized in response to the tolerance of morpho-physiological traits under Fe-toxic and -deficient soil conditions, and these traits need to be well integrated into breeding programs. A deeper understanding of the several factors that influence Fe absorption, uptake, and transport from soil to root and above-ground organs under FDS and FTS is needed to develop tolerant rice cultivars with improved grain yield. Therefore, the objective of this review paper is to congregate the different phenotypic screening methodologies for prospecting tolerant rice varieties and their responsible genetic traits, and Fe homeostasis related to all the known quantitative trait loci (QTLs), genes, and transporters, which could offer enormous information to rice breeders and biotechnologists to develop rice cultivars tolerant of Fe toxicity or deficiency. The mechanism of Fe regulation and transport from soil to grain needs to be understood in a systematic manner along with the cascade of metabolomics steps that are involved in the development of rice varieties tolerant of FTS and FDS. Therefore, the integration of breeding with advanced genome sequencing and omics technologies allows for the fine-tuning of tolerant genotypes on the basis of molecular genetics, and the further identification of novel genes and transporters that are related to Fe regulation from FTS and FDS conditions is incredibly important to achieve further success in this aspect. Full article
(This article belongs to the Section Plant Genetics, Genomics and Biotechnology)
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Article
Evolutionary Analysis of GH3 Genes in Six Oryza Species/Subspecies and Their Expression under Salinity Stress in Oryza sativa ssp. japonica
Plants 2019, 8(2), 30; https://doi.org/10.3390/plants8020030 - 24 Jan 2019
Cited by 25 | Viewed by 2882
Abstract
Glycoside Hydrolase 3 (GH3), a member of the Auxin-responsive gene family, is involved in plant growth, the plant developmental process, and various stress responses. The GH3 gene family has been well-studied in Arabidopsis thaliana and Zea mays. However, the evolution [...] Read more.
Glycoside Hydrolase 3 (GH3), a member of the Auxin-responsive gene family, is involved in plant growth, the plant developmental process, and various stress responses. The GH3 gene family has been well-studied in Arabidopsis thaliana and Zea mays. However, the evolution of the GH3 gene family in Oryza species remains unknown and the function of the GH3 gene family in Oryza sativa is not well-documented. Here, a systematic analysis was performed in six Oryza species/subspecies, including four wild rice species and two cultivated rice subspecies. A total of 13, 13, 13, 13, 12, and 12 members were identified in O. sativa ssp. japonica, O. sativa ssp. indica, Oryza rufipogon, Oryza nivara, Oryza punctata, and Oryza glumaepatula, respectively. Gene duplication events, structural features, conserved motifs, a phylogenetic analysis, chromosome locations, and Ka/Ks ratios of this important family were found to be strictly conservative across these six Oryza species/subspecies, suggesting that the expansion of the GH3 gene family in Oryza species might be attributed to duplication events, and this expansion could occur in the common ancestor of Oryza species, even in common ancestor of rice tribe (Oryzeae) (23.07~31.01 Mya). The RNA-seq results of different tissues displayed that OsGH3 genes had significantly different expression profiles. Remarkably, the qRT-PCR result after NaCl treatment indicated that the majority of OsGH3 genes play important roles in salinity stress, especially OsGH3-2 and OsGH3-8. This study provides important insights into the evolution of the GH3 gene family in Oryza species and will assist with further investigation of OsGH3 genes’ functions under salinity stress. Full article
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Article
Differential Expression Proteins Contribute to Race-Specific Resistant Ability in Rice (Oryza sativa L.)
Plants 2019, 8(2), 29; https://doi.org/10.3390/plants8020029 - 23 Jan 2019
Cited by 2 | Viewed by 1951
Abstract
Rice blast, caused by the fungus, Magnaporthe grisea (M. grisea), lead to the decrease of rice yields widely and destructively, threatening global food security. Although many resistant genes had been isolated and identified in various rice varieties, it is still not [...] Read more.
Rice blast, caused by the fungus, Magnaporthe grisea (M. grisea), lead to the decrease of rice yields widely and destructively, threatening global food security. Although many resistant genes had been isolated and identified in various rice varieties, it is still not enough to clearly understand the mechanism of race-specific resistant ability in rice, especially on the protein level. In this research, proteomic methods were employed to analyze the differentially expressed proteins (DEPs) in susceptible rice variety CO39 and its two near isogenic lines (NILs), CN-4a and CN-4b, in response to the infection of two isolates with different pathogenicity, GUY11 and 81278ZB15. A total of 50 DEPs with more than 1.5-fold reproducible change were identified. At 24 and 48 hpi of GUY11, 32 and 16 proteins in CN-4b were up-regulated, among which 16 and five were paralleled with the expression of their corresponding RNAs. Moreover, 13 of 50 DEPs were reported to be induced by M. grisea in previous publications. Considering the phenotypes of the three tested rice varieties, we found that 21 and 23 up-regulated proteins were responsible for the rice resistant ability to the two different blast isolates, 81278ZB15 and GUY11, respectively. Two distinct branches corresponding to GUY11 and 81278ZB15 were observed in the expression and function of the module cluster of DEPs, illuminating that the DEPs could be responsible for race-specific resistant ability in rice. In other words, DEPs in rice are involved in different patterns and functional modules’ response to different pathogenic race infection, inducing race-specific resistant ability in rice. Full article
(This article belongs to the Special Issue Induced Resistance (IR) of Plants)
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Article
Identification and Characterization of Mitogen-Activated Protein Kinase (MAPK) Genes in Sunflower (Helianthus annuus L.)
Plants 2019, 8(2), 28; https://doi.org/10.3390/plants8020028 - 22 Jan 2019
Cited by 10 | Viewed by 3635
Abstract
Mitogen-Activated Protein Kinase (MAPK) genes encode proteins that regulate biotic and abiotic stresses in plants through signaling cascades comprised of three major subfamilies: MAP Kinase (MPK), MAPK Kinase (MKK), and MAPKK Kinase (MKKK). The main objectives of this research were to conduct genome-wide [...] Read more.
Mitogen-Activated Protein Kinase (MAPK) genes encode proteins that regulate biotic and abiotic stresses in plants through signaling cascades comprised of three major subfamilies: MAP Kinase (MPK), MAPK Kinase (MKK), and MAPKK Kinase (MKKK). The main objectives of this research were to conduct genome-wide identification of MAPK genes in Helianthus annuus and examine functional divergence of these genes in relation to those in nine other plant species (Amborella trichopoda, Aquilegia coerulea, Arabidopsis thaliana, Daucus carota, Glycine max, Oryza sativa, Solanum lycopersicum, Sphagnum fallax, and Vitis vinifera), representing diverse taxonomic groups of the Plant Kingdom. A Hidden Markov Model (HMM) profile of the MAPK genes utilized reference sequences from A. thaliana and G. max, yielding a total of 96 MPKs and 37 MKKs in the genomes of A. trichopoda, A. coerulea, C. reinhardtii, D. carota, H. annuus, S. lycopersicum, and S. fallax. Among them, 28 MPKs and eight MKKs were confirmed in H. annuus. Phylogenetic analyses revealed four clades within each subfamily. Transcriptomic analyses showed that at least 19 HaMPK and seven HaMKK genes were induced in response to salicylic acid (SA), sodium chloride (NaCl), and polyethylene glycol (Peg) in leaves and roots. Of the seven published sunflower microRNAs, five microRNA families are involved in targeting eight MPKs. Additionally, we discussed the need for using MAP Kinase nomenclature guidelines across plant species. Our identification and characterization of MAP Kinase genes would have implications in sunflower crop improvement, and in advancing our knowledge of the diversity and evolution of MAPK genes in the Plant Kingdom. Full article
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Article
Autotoxicity of Diterpenes Present in Leaves of Cistus ladanifer L.
Plants 2019, 8(2), 27; https://doi.org/10.3390/plants8020027 - 22 Jan 2019
Cited by 8 | Viewed by 1666
Abstract
Cistus ladanifer has been described as an allelopathic and autoallelopathic species, and the compounds that could be involved in its autotoxicity are the flavonoids and diterpenes present in the exudate of its leaves. The aim of this study was to determine which family [...] Read more.
Cistus ladanifer has been described as an allelopathic and autoallelopathic species, and the compounds that could be involved in its autotoxicity are the flavonoids and diterpenes present in the exudate of its leaves. The aim of this study was to determine which family of compounds, either phenols or terpenes, are responsible for the autoallelopathic activity quantified in C. ladanifer. These compounds were extracted from the exudate of young leaves collected in spring and separated by column chromatography into two fractions: diterpenes and flavonoids. The obtained results showed that flavonoids, at the tested concentrations, did not have a negative effect on any of the parameters quantified in the germination process of C. ladanifer seeds. On the other hand, the germination, seedling size and seedling establishment, quantified through the germination index and rate, were negatively affected by the tested diterpene solutions. In view of the obtained results, it was concluded that the compounds involved in the autoallelopathy process of C. ladanifer are diterpenes. Full article
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Review
Inhibition of Key Citrus Postharvest Fungal Strains by Plant Extracts In Vitro and In Vivo: A Review
Plants 2019, 8(2), 26; https://doi.org/10.3390/plants8020026 - 22 Jan 2019
Cited by 58 | Viewed by 5679
Abstract
Citrus fruits are subjected to a diversity of postharvest diseases caused by various pathogens during picking, packing, storage and transportation. Green and blue molds, caused by Penicillium digitatum and Penicillium italicum, respectively, are two major postharvest citrus diseases and cause significant economic [...] Read more.
Citrus fruits are subjected to a diversity of postharvest diseases caused by various pathogens during picking, packing, storage and transportation. Green and blue molds, caused by Penicillium digitatum and Penicillium italicum, respectively, are two major postharvest citrus diseases and cause significant economic losses during the commercialization phase. Currently, the control of postharvest citrus diseases relies mainly on the use of synthetic fungicides, which usually result in the resistance against fungal attack, environment pollution and health hazards. In recent years, much attention has been given to the preservation of citrus by naturally isolated edible plant extracts, medicinal plant extracts, Citrus extracts and volatiles, et al. Scientists worldwide devote their time and energy to discover the high effect, low toxicity, safety and inexpensive plant-derived fungicides. The current review will highlight plant-derived fungicides and chemical constituents that aim to inhibit P. digitatum and P. italicum in vitro and in vivo. Coatings enriched with plant extracts could be good alternative methods for Citrus fruits preservation. Problems and prospects of the research and development of plant-derived natural fungicides will also be discussed in this article. Full article
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Review
Sieve Plate Pores in the Phloem and the Unknowns of Their Formation
Plants 2019, 8(2), 25; https://doi.org/10.3390/plants8020025 - 22 Jan 2019
Cited by 12 | Viewed by 4504
Abstract
Sieve pores of the sieve plates connect neighboring sieve elements to form the conducting sieve tubes of the phloem. Sieve pores are critical for phloem function. From the 1950s onwards, when electron microscopes became increasingly available, the study of their formation had been [...] Read more.
Sieve pores of the sieve plates connect neighboring sieve elements to form the conducting sieve tubes of the phloem. Sieve pores are critical for phloem function. From the 1950s onwards, when electron microscopes became increasingly available, the study of their formation had been a pillar of phloem research. More recent work on sieve elements instead has largely focused on sieve tube hydraulics, phylogeny, and eco-physiology. Additionally, advanced molecular and genetic tools available for the model species Arabidopsis thaliana helped decipher several key regulatory mechanisms of early phloem development. Yet, the downstream differentiation processes which form the conductive sieve tube are still largely unknown, and our understanding of sieve pore formation has only moderately progressed. Here, we summarize our current knowledge on sieve pore formation and present relevant recent advances in related fields such as sieve element evolution, physiology, and plasmodesmata formation. Full article
(This article belongs to the Special Issue Plant Phloem Development)
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