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Plants, Volume 7, Issue 3 (September 2018)

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Cover Story (view full-size image) Cellulose is the most abundant biopolymer on the planet, and it is produced by large cellulose [...] Read more.
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Open AccessArticle Fast Regulation of Hormone Metabolism Contributes to Salt Tolerance in Rice (Oryza sativa spp. Japonica, L.) by Inducing Specific Morpho-Physiological Responses
Received: 24 August 2018 / Revised: 10 September 2018 / Accepted: 13 September 2018 / Published: 15 September 2018
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Abstract
Clear evidence has highlighted a role for hormones in the plant stress response, including salt stress. Interplay and cross-talk among different hormonal pathways are of vital importance in abiotic stress tolerance. A genome-wide transcriptional analysis was performed on leaves and roots of three-day
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Clear evidence has highlighted a role for hormones in the plant stress response, including salt stress. Interplay and cross-talk among different hormonal pathways are of vital importance in abiotic stress tolerance. A genome-wide transcriptional analysis was performed on leaves and roots of three-day salt treated and untreated plants of two Italian rice varieties, Baldo and Vialone Nano, which differ in salt sensitivity. Genes correlated with hormonal pathways were identified and analyzed. The contents of abscisic acid, indoleacetic acid, cytokinins, and gibberellins were measured in roots, stems, and leaves of seedlings exposed for one and three days to salt stress. From the transcriptomic analysis, a huge number of genes emerged as being involved in hormone regulation in response to salt stress. The expression profile of genes involved in biosynthesis, signaling, response, catabolism, and conjugation of phytohormones was analyzed and integrated with the measurements of hormones in roots, stems, and leaves of seedlings. Significant changes in the hormone levels, along with differences in morphological responses, emerged between the two varieties. These results support the faster regulation of hormones metabolism in the tolerant variety that allows a prompt growth reprogramming and the setting up of an acclimation program, leading to specific morpho-physiological responses and growth recovery. Full article
(This article belongs to the Special Issue Salt and Water Stress Tolerance in Plants)
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Open AccessReview Primary Structure Analysis of Antifungal Peptides from Cultivated and Wild Cereals
Received: 14 July 2018 / Revised: 31 August 2018 / Accepted: 6 September 2018 / Published: 12 September 2018
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Abstract
Cereal-derived bioactive peptides with antimicrobial activity have been poorly explored compared to those from dicotyledonous plants. Furthermore, there are a few reports addressing the structural differences between antimicrobial peptides (AMPs) from cultivated and wild cereals, which may shed light on significant varieties in
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Cereal-derived bioactive peptides with antimicrobial activity have been poorly explored compared to those from dicotyledonous plants. Furthermore, there are a few reports addressing the structural differences between antimicrobial peptides (AMPs) from cultivated and wild cereals, which may shed light on significant varieties in the range and level of their antimicrobial activity. We performed a primary structure analysis of some antimicrobial peptides from wild and cultivated cereals to find out the features that are associated with the much higher antimicrobial resistance characteristic of wild plants. In this review, we identified and analyzed the main parameters determining significant antifungal activity. They relate to a high variability level in the sequences of C-terminal fragments and a high content of hydrophobic amino acid residues in the biologically active defensins in wild cereals, in contrast to AMPs from cultivated forms that usually exhibit weak, if any, activity. We analyzed the similarity of various physicochemical parameters between thionins and defensins. The presence of a high divergence on a fixed part of any polypeptide that is close to defensins could be a determining factor. For all of the currently known hevein-like peptides of cereals, we can say that the determining factor in this regard is the structure of the chitin-binding domain, and in particular, amino acid residues that are not directly involved in intermolecular interaction with chitin. The analysis of amino acid sequences of alpha-hairpinins (hairpin-like peptides) demonstrated much higher antifungal activity and more specificity of the peptides from wild cereals compared with those from wheat and corn, which may be associated with the presence of a mini cluster of positively charged amino acid residues. In addition, at least one hydrophobic residue may be responsible for binding to the components of fungal cell membranes. Full article
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Open AccessArticle Life Cycle and Genetic Diversity of Symplocarpus nipponicus (Araceae), an Endangered Species in Japan
Received: 16 August 2018 / Revised: 7 September 2018 / Accepted: 9 September 2018 / Published: 11 September 2018
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Abstract
Symplocarpus nipponicus, a member of the Araceae family, is an endangered plant in several prefectures in Japan. For the conservation of this wild species, we investigated the morphology, life cycle, and genetic diversity of three wild populations. By fixed-point observation over several
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Symplocarpus nipponicus, a member of the Araceae family, is an endangered plant in several prefectures in Japan. For the conservation of this wild species, we investigated the morphology, life cycle, and genetic diversity of three wild populations. By fixed-point observation over several years, we found that it takes at least four years for the plant to set the inflorescences consisting of spadices and spathes, and another two years for it to set mature seeds. To examine the genetic diversity in the wild population, we developed 11 novel microsatellite markers and investigated the genetic variation in three populations in Kyoto Prefecture: Ayabe, Hanase, and Momoi. The Ayabe population carried less genetic variation than the other two areas, suggesting the isolation of the habitat and thus a higher risk of extinction. Our results provide basic knowledge of the ecological aspects of S. nipponicus, as well as molecular techniques for the assessment of its genetic diversity, and thus are useful for the conservation of this endangered species. Full article
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Open AccessReview Physiology Based Approaches for Breeding of Next-Generation Food Legumes
Received: 31 July 2018 / Revised: 31 August 2018 / Accepted: 7 September 2018 / Published: 8 September 2018
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Abstract
Plant breeders and agricultural scientists of the 21st century are challenged to increase the yield potentials of crops to feed the growing world population. Climate change, the resultant stresses and increasing nutrient deficiencies are factors that are to be considered in designing modern
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Plant breeders and agricultural scientists of the 21st century are challenged to increase the yield potentials of crops to feed the growing world population. Climate change, the resultant stresses and increasing nutrient deficiencies are factors that are to be considered in designing modern plant breeding pipelines. Underutilized food legumes have the potential to address these issues and ensure food security in developing nations of the world. Food legumes in the past have drawn limited research funding and technological attention when compared to cereal crops. Physiological breeding strategies that were proven to be successful in cereals are to be adapted to legume crop improvement to realize their potential. The gap between breeders and physiologists should be narrowed by collaborative approaches to understand complex traits in legumes. This review discusses the potential of physiology based approaches in food legume breeding and how they impact yield gains and abiotic stress tolerance in these crops. The influence of roots and root system architectures in food legumes’ breeding is also discussed. Molecular breeding to map the relevant physiological traits and the potentials of gene editing those traits are detailed. It is imperative to unlock the potentials of these underutilized crops to attain sustainable environmental and nutritional food security. Full article
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Open AccessArticle Proteomic Analysis of Rapeseed Root Response to Waterlogging Stress
Received: 6 August 2018 / Revised: 29 August 2018 / Accepted: 30 August 2018 / Published: 7 September 2018
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Abstract
The overall health of a plant is constantly affected by the changing and hostile environment. Due to climate change and the farming pattern of rice (Oryza sativa) and rapeseed (Brassica napus L.), stress from waterlogging poses a serious threat to
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The overall health of a plant is constantly affected by the changing and hostile environment. Due to climate change and the farming pattern of rice (Oryza sativa) and rapeseed (Brassica napus L.), stress from waterlogging poses a serious threat to productivity assurance and the yield of rapeseed in China’s Yangtze River basin. In order to improve our understanding of the complex mechanisms behind waterlogging stress and identify waterlogging-responsive proteins, we firstly conducted iTRAQ (isobaric tags for relative and absolute quantification)-based quantitative proteomic analysis of rapeseed roots under waterlogging treatments, for both a tolerant cultivar ZS9 and sensitive cultivar GH01. A total of 7736 proteins were identified by iTRAQ, of which several hundred showed different expression levels, including 233, 365, and 326 after waterlogging stress for 4H, 8H, and 12H in ZS9, respectively, and 143, 175, and 374 after waterlogging stress for 4H, 8H, and 12H in GH01, respectively. For proteins repeatedly identified at different time points, gene ontology (GO) cluster analysis suggested that the responsive proteins of the two cultivars were both enriched in the biological process of DNA-dependent transcription and the oxidation–reduction process, and response to various stress and hormone stimulus, while different distribution frequencies in the two cultivars was investigated. Moreover, overlap proteins with similar or opposite tendencies of fold change between ZS9 and GH01 were observed and clustered based on the different expression ratios, suggesting the two genotype cultivars exhibited diversiform molecular mechanisms or regulation pathways in their waterlogging stress response. The following qRT-PCR (quantitative real-time polymerase chain reaction) results verified the candidate proteins at transcription levels, which were prepared for further research. In conclusion, proteins detected in this study might perform different functions in waterlogging responses and would provide information conducive to better understanding adaptive mechanisms under environmental stresses. Full article
(This article belongs to the Special Issue Plants Reacts to the Changing Environment)
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Open AccessReview Plants of Genus Mentha: From Farm to Food Factory
Received: 30 July 2018 / Revised: 28 August 2018 / Accepted: 29 August 2018 / Published: 4 September 2018
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Abstract
Genus Mentha, a member of Lamiaceae family, encompasses a series of species used on an industrial scale and with a well-described and developed culture process. Extracts of this genus are traditionally used as foods and are highly valued due to the presence
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Genus Mentha, a member of Lamiaceae family, encompasses a series of species used on an industrial scale and with a well-described and developed culture process. Extracts of this genus are traditionally used as foods and are highly valued due to the presence of significant amounts of antioxidant phenolic compounds. Many essential oil chemotypes show distinct aromatic flavor conferred by different terpene proportions. Mint extracts and their derived essential oils exert notable effects against a broad spectrum of bacteria, fungi or yeasts, tested both in vitro or in various food matrices. Their chemical compositions are well-known, which suggest and even prompt their safe use. In this review, genus Mentha plant cultivation, phytochemical analysis and even antimicrobial activity are carefully described. Also, in consideration of its natural origin, antioxidant and antimicrobial properties, a special emphasis was given to mint-derived products as an interesting alternative to artificial preservatives towards establishing a wide range of applications for shelf-life extension of food ingredients and even foodstuffs. Mentha cultivation techniques markedly influence its phytochemical composition. Both extracts and essential oils display a broad spectrum of activity, closely related to its phytochemical composition. Therefore, industrial implementation of genus Mentha depends on its efficacy, safety and neutral taste. Full article
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Open AccessArticle Inhibition of Lipid Peroxidation of Kiwicha (Amaranthus caudatus) Hydrolyzed Protein Using Zebrafish Larvae and Embryos
Received: 30 June 2018 / Revised: 25 August 2018 / Accepted: 29 August 2018 / Published: 2 September 2018
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Abstract
Amaranth protein concentrate (APC) was hydrolyzed under in vitro gastrointestinal conditions. APC proteins were partially degraded by pepsin at pHs 1.2, 2.0, and 3.2. During the intestinal phase (pepsin/pancreatin enzymes at pH 7.0), no polypeptide bands were observed in the gel, suggesting the
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Amaranth protein concentrate (APC) was hydrolyzed under in vitro gastrointestinal conditions. APC proteins were partially degraded by pepsin at pHs 1.2, 2.0, and 3.2. During the intestinal phase (pepsin/pancreatin enzymes at pH 7.0), no polypeptide bands were observed in the gel, suggesting the susceptibility of amaranth proteins to the action of digestive enzymes. The potent in vitro inhibition of lipid peroxidation, shown by the gastric and intestinal digests, was confirmed in the zebrafish larvae, with a 72.86% reduction in oxidation of lipids in the presence of the gastric hydrolysate at pH 2.0, compared to a 95.72% reduction in the presence of the gastrointestinal digest. APC digests were capable of reducing reactive oxygen species (ROS) production in the zebrafish embryo model with a value of fluorescence of 52.5% for the gastric hydrolysate, and 48.4% for the intestinal hydrolysate. Full article
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Open AccessArticle Genome-Wide Investigation of the Role of MicroRNAs in Desiccation Tolerance in the Resurrection Grass Tripogon loliiformis
Received: 31 July 2018 / Revised: 24 August 2018 / Accepted: 29 August 2018 / Published: 31 August 2018
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Abstract
Drought causes approximately two-thirds of crop and yield loss worldwide. To sustain future generations, there is a need to develop robust crops with enhanced water use efficiency. Resurrection plants are naturally resilient and tolerate up to 95% water loss with the ability to
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Drought causes approximately two-thirds of crop and yield loss worldwide. To sustain future generations, there is a need to develop robust crops with enhanced water use efficiency. Resurrection plants are naturally resilient and tolerate up to 95% water loss with the ability to revive upon watering. Stress is genetically encoded and resilient species may garner tolerance by tightly regulating the expression of stress-related genes. MicroRNAs (miRNAs) post-transcriptionally regulate development and other stress response processes in eukaryotes. However, their role in resurrection plant desiccation tolerance is poorly understood. In this study, small RNA sequencing and miRNA expression profiling was conducted using Tripogon loliiformis plants subjected to extreme water deficit conditions. Differentially expressed miRNA profiles, target mRNAs, and their regulatory processes were elucidated. Gene ontology enrichment analysis revealed that development, stress response, and regulation of programmed cell death biological processes; Oxidoreductase and hydrolyase molecular activities; and SPL, MYB, and WRKY transcription factors were targeted by miRNAs during dehydration stress, indicating the indispensable regulatory role of miRNAs in desiccation tolerance. This study provides insights into the molecular mechanisms of desiccation tolerance in the resurrection plant T. loliiformis. This information will be useful in devising strategies for crop improvement on enhanced drought tolerance and water use efficiency. Full article
(This article belongs to the Special Issue The Role of MicroRNAs in Plants)
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Open AccessArticle Chiricaspi (Brunfelsia grandiflora, Solanaceae), a Pharmacologically Promising Plant
Received: 28 June 2018 / Revised: 6 August 2018 / Accepted: 13 August 2018 / Published: 18 August 2018
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Abstract
This study’s objective was to evaluate the rescued traditional knowledge about the chiricaspi (Brunfelsia grandiflora s.l.), obtained in an isolated Canelo-Kichwa Amazonian community in the Pastaza province (Ecuador). This approach demonstrates well the value of biodiversity conservation in an endangered ecoregion. The
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This study’s objective was to evaluate the rescued traditional knowledge about the chiricaspi (Brunfelsia grandiflora s.l.), obtained in an isolated Canelo-Kichwa Amazonian community in the Pastaza province (Ecuador). This approach demonstrates well the value of biodiversity conservation in an endangered ecoregion. The authors describe the ancestral practices that remain in force today. They validated them through bibliographic revisions in data megabases, which presented activity and chemical components. The authors also propose possible routes for the development of new bioproducts based on the plant. In silico research about new drug design based on traditional knowledge about this species can produce significant progress in specific areas of childbirth, anesthesiology, and neurology. Full article
(This article belongs to the Special Issue Medicinal Plants and Natural Product Research)
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Open AccessArticle Sarcocornia neei as an Indicator of Environmental Pollution: A Comparative Study in Coastal Wetlands of Central Chile
Received: 22 June 2018 / Revised: 7 August 2018 / Accepted: 9 August 2018 / Published: 17 August 2018
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Abstract
Being adapted to saline environments, halophytes are plant species that have received considerable attention due to their ability to cope with environmental stress factors, such as high concentrations of soluble salts and heavy metals. In this work, we focused on determining if the
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Being adapted to saline environments, halophytes are plant species that have received considerable attention due to their ability to cope with environmental stress factors, such as high concentrations of soluble salts and heavy metals. In this work, we focused on determining if the Sarcocornia neei (S. neei) plant can be considered as an indicator of heavy metal pollution in soil. This was done by analyzing the concentration of cadmium (Cd), lead (Pb), copper (Cu), and arsenic (As) in plants and soil sampled from two wetlands in the central zone of Chile: a wetland contaminated by industrial activities and a wetland protected by the Chilean government. In addition, 14 fertility parameters (pH, electrical conductivity, organic matter, nitrogen (N), phosphorus (P), potassium (K), sodium (Na), Pb, calcium (Ca), magnesium (Mg), Manganese (Mn), zinc (Zn), iron (Fe), and boron (B)) were analyzed for soil samples in both wetlands. This was done to differentiate between available elements and contamination by heavy metals. Plant and soil samples in the contaminated wetland exhibited significantly higher heavy metal concentrations in comparison to samples analyzed from the protected wetland. This indicates that the S. neei plant can be further researched as an indicator of heavy metal pollution in saline soils and possibly for phytoremediation purposes. Full article
(This article belongs to the Special Issue Wetland Plants: Biodiversity and Ecological Gradients)
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Open AccessArticle Tomato ATP-Binding Cassette Transporter SlABCB4 Is Involved in Auxin Transport in the Developing Fruit
Received: 15 July 2018 / Revised: 5 August 2018 / Accepted: 9 August 2018 / Published: 13 August 2018
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Abstract
Plant ATP binding cassette (ABC) transporters are membrane proteins that are important for transporting a wide range of compounds, including secondary metabolites and phytohormones. In Arabidopsis, some members of the ABCB subfamily of ABC transporter, also known as Multi-Drug Resistance proteins (MDRs), have
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Plant ATP binding cassette (ABC) transporters are membrane proteins that are important for transporting a wide range of compounds, including secondary metabolites and phytohormones. In Arabidopsis, some members of the ABCB subfamily of ABC transporter, also known as Multi-Drug Resistance proteins (MDRs), have been implicated in auxin transport. However, reports on the roles of the auxin-mediated ABCBs in fleshy fruit development are rare. Here, we present that SlABCB4, a member of the tomato ABCB subfamily, transports auxin in the developing fruit of tomato. Transient expression of SlABCB4-GFP fusion proteins in tobacco cells showed plasma membrane localization. The transport activity of SlABCB4, expressed in Nicotiana benthamiana protoplasts, revealed substrate specificity for indole-3-acetic acid export. Gene expression analysis of SlABCB4 revealed high expression levels at the early stages of fruit development. Therefore, SlABCB4 is considered to facilitate auxin distribution in tomato fruit, which is important for tomato fruit development. Full article
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Open AccessArticle Effect of Selenium on the Responses Induced by Heat Stress in Plant Cell Cultures
Received: 11 July 2018 / Revised: 9 August 2018 / Accepted: 10 August 2018 / Published: 11 August 2018
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Abstract
High temperatures are a significant stress factor for plants. In fact, many biochemical reactions involved in growth and development are sensitive to temperature. In particular, heat stress (HS) represents a severe issue for plant productivity and strategies to obtain high yields under this
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High temperatures are a significant stress factor for plants. In fact, many biochemical reactions involved in growth and development are sensitive to temperature. In particular, heat stress (HS) represents a severe issue for plant productivity and strategies to obtain high yields under this condition are important goals in agriculture. While selenium (Se) is a nutrient for humans and animals, its role as a plant micronutrient is still questioned. Se can prevent several abiotic stresses (drought, heat, UV, salinity, heavy metals), but the action mechanisms are poorly understood. Se seems to regulate reactive oxygen species (ROS) and to inhibit heavy metals transport. In addition, it has been demonstrated that Se is essential for a correct integrity of cell membranes and chloroplasts, especially the photosynthetic apparatus. Previous results showed that in tobacco (Nicotiana tabacum cv. Bright-Yellow 2) cultures HS (5 min at 50 °C) induced cell death with apoptotic features, accompanied by oxidative stress and changes in the levels of stress-related proteins. In this work we investigated the effect of Se on the responses induced by HS. The obtained results show that Se markedly reduces the effects of HS on cell vitality, cytoplasmic shrinkage, superoxide anion production, membrane lipids peroxidation, activity of caspase-3-like proteases, and the levels of some stress-related proteins (Hsp90, BiP, 14-3-3s, cytochrome c). Full article
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Open AccessArticle Interactions between Mycorrhizal Fungi, Tea Wastes, and Algal Biomass Affecting the Microbial Community, Soil Structure, and Alleviating of Salinity Stress in Corn Yield (Zea mays L.)
Received: 5 June 2018 / Revised: 27 July 2018 / Accepted: 2 August 2018 / Published: 8 August 2018
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Abstract
Soil salinity has an adverse impact on soil biological properties and growth of corn plant, majorly in arid and semi-arid lands. A mesocosm experiment was conducted to investigate the effect of mycorrhizal fungi (M) (Glomus mosseae), tea wastes (T), algal dried
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Soil salinity has an adverse impact on soil biological properties and growth of corn plant, majorly in arid and semi-arid lands. A mesocosm experiment was conducted to investigate the effect of mycorrhizal fungi (M) (Glomus mosseae), tea wastes (T), algal dried biomass (A), and their combinations on soil respiration, total bacteria, total fungi, soil mean weight diameter (MWD), and corn yield (Zeamays L.). under saline and non-saline soils. Results showed that M, T, and A treatments increased significantly CO2 release compared to the control. Whereas, M significantly decreased CO2 release compared to T and A treatments. In non-saline soil, M increased greatly MWD, bacterial and fungal counts, and infection rate. Whereas, the opposite was true in the saline soil; neither M nor T improved bacterial communities and MWD. However, in the saline soil, M + T was highly efficient in improving MWD, SOC, bacterial and fungal counts, infection rate, and corn grain yield. It can be suggested that the inoculation of mycorrhizal fungi with tea wastes in saline soils considered an important strategy that increases the toleration of the corn plant to salinity by improving soil microbial activity, MWD, SOC, infection rate, and total grain yield. Full article
(This article belongs to the Special Issue Salt and Water Stress Tolerance in Plants)
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Open AccessArticle Three Methods of Estimating Mesophyll Conductance Agree Regarding its CO2 Sensitivity in the Rubisco-Limited Ci Range
Received: 27 June 2018 / Revised: 24 July 2018 / Accepted: 3 August 2018 / Published: 5 August 2018
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Abstract
Whether the mesophyll conductance to CO2 movement (gm) within leaves of C3 plants changes with CO2 concentration remains a matter of debate, particularly at low CO2 concentrations. We tested for changes in gm over the range
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Whether the mesophyll conductance to CO2 movement (gm) within leaves of C3 plants changes with CO2 concentration remains a matter of debate, particularly at low CO2 concentrations. We tested for changes in gm over the range of sub-stomatal CO2 concentrations (Ci) for which Rubisco activity limited photosynthesis (A) in three plant species grown under the same conditions. Mesophyll conductance was estimated by three independent methods: the oxygen sensitivity of photosynthesis, variable J fluorescence combined with gas exchange, and the curvature of the Rubisco-limited A vs. Ci curve. The latter assay used a new method of rapidly obtaining data points at approximately every 3 μmol mol−1 for Rubisco-limited A vs. Ci curves, allowing separate estimates of curvature over limited Ci ranges. In two species, soybean and sunflower, no change in gm with Ci was detected using any of the three methods of estimating gm. In common bean measured under the same conditions as the other species, all three methods indicated large decreases in gm with increasing Ci. Therefore, change in gm with Ci in the Rubsico-limited region of A vs. Ci curves depended on the species, but not on the method of estimating gm. Full article
(This article belongs to the Special Issue Plant Photosynthetic Gas Exchange: a Current Perspective)
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Open AccessArticle A Cyclic Nucleotide-Gated Channel, HvCNGC2-3, Is Activated by the Co-Presence of Na+ and K+ and Permeable to Na+ and K+ Non-Selectively
Received: 11 June 2018 / Revised: 9 July 2018 / Accepted: 24 July 2018 / Published: 26 July 2018
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Abstract
Cyclic nucleotide-gated channels (CNGCs) have been postulated to contribute significantly in plant development and stress resistance. However, their electrophysiological properties remain poorly understood. Here, we characterized barley CNGC2-3 (HvCNGC2-3) by the two-electrode voltage-clamp technique in the Xenopus laevis oocyte heterologous expression system. Current
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Cyclic nucleotide-gated channels (CNGCs) have been postulated to contribute significantly in plant development and stress resistance. However, their electrophysiological properties remain poorly understood. Here, we characterized barley CNGC2-3 (HvCNGC2-3) by the two-electrode voltage-clamp technique in the Xenopus laevis oocyte heterologous expression system. Current was not observed in X. laevis oocytes injected with HvCNGC2-3 complementary RNA (cRNA) in a bathing solution containing either Na+ or K+ solely, even in the presence of 8-bromoadenosine 3′,5′-cyclic monophosphate (8Br-cAMP) or 8-bromoguanosine 3′,5′-cyclic monophosphate (8Br-cGMP). A weakly voltage-dependent slow hyperpolarization-activated ion current was observed in the co-presence of Na+ and K+ in the bathing solution and in the presence of 10 µM 8Br-cAMP, but not 8Br-cGMP. Permeability ratios of HvCNGC2-3 to K+, Na+ and Cl were determined as 1:0.63:0.03 according to reversal-potential analyses. Amino-acid replacement of the unique ion-selective motif of HvCNGC2-3, AQGL, with the canonical motif, GQGL, resulted in the abolition of the current. This study reports a unique two-ion-dependent activation characteristic of the barley CNGC, HvCNGC2-3. Full article
(This article belongs to the Special Issue Salt and Water Stress Tolerance in Plants)
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Open AccessArticle Polygonum multiflorum Extract Exerts Antioxidative Effects and Increases Life Span and Stress Resistance in the Model Organism Caenorhabditis elegans via DAF-16 and SIR-2.1
Received: 19 June 2018 / Revised: 9 July 2018 / Accepted: 13 July 2018 / Published: 20 July 2018
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Abstract
Extracts of the Chinese plant Polygonum multiflorum (PME) are used for medicinal purposes as well as food supplement due to anti-aging effects. Despite of the common use of these food supplements, experimental data on physiological effects of PME and its underlying molecular mechanisms
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Extracts of the Chinese plant Polygonum multiflorum (PME) are used for medicinal purposes as well as food supplement due to anti-aging effects. Despite of the common use of these food supplements, experimental data on physiological effects of PME and its underlying molecular mechanisms in vivo are limited. We used the model organism Caenorhabditis elegans to analyze anti-aging-effects of PME in vivo (life span, lipofuscin accumulation, oxidative stress resistance, thermal stress resistance) as well as the molecular signaling pathways involved. The effects of PME were examined in wildtype animals and mutants defective in the sirtuin-homologue SIR-2.1 (VC199) and the FOXO-homologue DAF-16 (CF1038). PME possesses antioxidative effects in vivo and increases oxidative stress resistance of the nematodes. While the accumulation of lipofuscin is only slightly decreased, PME causes a significant elongation (18.6%) of mean life span. DAF-16 is essential for the reduction of thermally induced ROS accumulation, while the resistance against paraquat-induced oxidative stress is dependent on SIR-2.1. For the extension of the life span, both DAF-16 and SIR-2.1 are needed. We demonstrate that PME exerts protective effects in C. elegans via modulation of distinct intracellular pathways. Full article
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Open AccessArticle Seasonal Growth of Zygophyllum dumosum Boiss.: Summer Dormancy Is Associated with Loss of the Permissive Epigenetic Marker Dimethyl H3K4 and Extensive Reduction in Proteins Involved in Basic Cell Functions
Received: 3 June 2018 / Revised: 22 June 2018 / Accepted: 4 July 2018 / Published: 15 July 2018
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Abstract
Plants thriving in desert environments are suitable for studying mechanisms for plant survival under extreme seasonal climate variation. We studied epigenetic mechanisms underlying seasonal growth cycles in the desert plant Zygophyllum dumosum Boiss., which was previously shown to be deficient in repressive markers
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Plants thriving in desert environments are suitable for studying mechanisms for plant survival under extreme seasonal climate variation. We studied epigenetic mechanisms underlying seasonal growth cycles in the desert plant Zygophyllum dumosum Boiss., which was previously shown to be deficient in repressive markers of di-methyl and tri-methyl H3K9 and their association with factors regulating basic cell functions. We showed a contingent association between rainfall and seasonal growth and the epigenetic marker of dimethyl H3K4, which disappears upon entry into the dry season and the acquisition of a dormant state. DNA methylation is not affected by a lack of H3K9 di-methyl and tri-methyl. Changes in methylation can occur between the wet and dry season. Proteome analysis of acid soluble fractions revealed an extensive reduction in ribosomal proteins and in proteins involved in chloroplasts and mitochondrial activities during the dry seasons concomitantly with up-regulation of molecular chaperone HSPs. Our results highlight mechanisms underlying Z. dumosum adaptation to seasonal climate variation. Particularly, summer dormancy is associated with a loss of the permissive epigenetic marker dimethyl H3K4, which might facilitate genome compaction concomitantly with a significant reduction in proteins involved in basic cell functions. HSP chaperones might safeguard the integrity of cell components. Full article
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Open AccessArticle Inheritance and Genetic Mapping of the Reduced Height (Rht18) Gene in Wheat
Received: 12 June 2018 / Revised: 3 July 2018 / Accepted: 11 July 2018 / Published: 15 July 2018
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Abstract
Short-statured plants revolutionized agriculture during the 1960s due to their ability to resist lodging, increased their response to fertilizers, and improved partitioning of assimilates which led to yield gains. Of more than 21 reduced-height (Rht) genes reported in wheat, only three—
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Short-statured plants revolutionized agriculture during the 1960s due to their ability to resist lodging, increased their response to fertilizers, and improved partitioning of assimilates which led to yield gains. Of more than 21 reduced-height (Rht) genes reported in wheat, only three—Rht-B1b, Rht-D1b, and Rht8—were extensively used in wheat breeding programs. The remaining reduced height mutants have not been utilized in breeding programs due to the lack of characterization. In the present study, we determined the inheritance of Rht18 and developed a genetic linkage map of the region containing Rht18. The height distribution of the F2 population was skewed towards the mutant parent, indicating that the dwarf allele (Rht18) is semi-dominant over the tall allele (rht18). Rht18 was mapped on chromosome 6A between markers barc146 and cfd190 with a genetic distance of 26.2 and 17.3 cM, respectively. In addition to plant height, agronomically important traits, like awns and tiller numbers, were also studied in the bi-parental population. Although the average tiller number was very similar in both parents, the F2 population displayed a normal distribution for tiller number with the majority of plants having phenotype similar to the parents. Transgressive segregation was observed for plant height and tiller number in F2 population. This study enabled us to select a semi-dwarf line with superior agronomic characteristics that could be utilized in a breeding program. The identification of SSRs associated with Rht18 may improve breeders’ effectiveness in selecting desired semi-dwarf lines for developing new wheat cultivars. Full article
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Open AccessArticle Biochar Remediation Improves the Leaf Mineral Composition of Telfairia occidentalis Grown on Gas Flared Soil
Received: 31 May 2018 / Revised: 24 June 2018 / Accepted: 25 June 2018 / Published: 13 July 2018
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Abstract
This study evaluates the effects of remediation of gas flared soil by biochar on the nutritional composition of cultivated Telfairia occidentalis leaves, relative to non-gas flared soil. Gas flared soils are degraded due to the presence of heavy metals, noxious gases, carbon soot
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This study evaluates the effects of remediation of gas flared soil by biochar on the nutritional composition of cultivated Telfairia occidentalis leaves, relative to non-gas flared soil. Gas flared soils are degraded due to the presence of heavy metals, noxious gases, carbon soot and acidic rain. Biochar produced from oil palm fibre was applied at five different amounts: 0 t ha−1, 7.1 t ha−1, 13.9 t ha−1, 20.9 t ha−1 and 28.0 t ha−1 to containerized soils (both gas flared and control soil), inside a greenhouse, which were allowed to mineralize for two weeks. Two viable seeds of T. occidentalis per replicate were sown. After eight weeks of growth, leaves were harvested, dried and chemically analyzed. Application of biochar significantly increased leaf ash and crude fibre content of Telfairia occidentalis. Plants from soil treated with 13.9 t ha−1 of biochar had the highest concentrations of vitamins A, B1, B2, B6, C and E irrespective of soil type. Maximum increase in leaf vitamin and mineral content was obtained from leaves cultivated on gas flared soil treated with 13.9 t ha−1 and 7.1 t ha−1 of biochar respectively. The results show that biochar treatment can increase leaf mineral concentrations and that this effect is dependent on the amount of biochar application. Full article
Open AccessArticle Identification of Genomic Regions Contributing to Protein Accumulation in Wheat under Well-Watered and Water Deficit Growth Conditions
Received: 6 June 2018 / Revised: 28 June 2018 / Accepted: 4 July 2018 / Published: 11 July 2018
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Abstract
Sustaining wheat production under low-input conditions through development and identifying genotypes with enhanced nutritional quality are two current concerns of wheat breeders. Wheat grain total protein content, to no small extent, determines the economic and nutritive value of wheat. Therefore, the objectives of
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Sustaining wheat production under low-input conditions through development and identifying genotypes with enhanced nutritional quality are two current concerns of wheat breeders. Wheat grain total protein content, to no small extent, determines the economic and nutritive value of wheat. Therefore, the objectives of this study are to identify accessions with high and low grain protein content (GPC) under well-watered and water-deficit growth conditions and to locate genomic regions that contribute to GPC accumulation. Spring wheat grains obtained from 2111 accessions that were grown under well-watered and water-deficit conditions were assessed for GPC using near-infrared spectroscopy (NIR). Results indicated significant influences of moisture, genotype, and genotype × environment interaction on the GPC accumulation. Furthermore, genotypes exhibited a wide range of variation for GPC, indicating the presence of high levels of genetic variability among the studied accessions. Around 366 (166 with high GPC and 200 with low GPC) wheat genotypes performed relatively the same across environments, which implies that GPC accumulation in these genotypes was less responsive to water deficit. Genome-wide association mapping results indicated that seven single nucleotide polymorphism (SNPs) were linked with GPC under well-watered growth conditions, while another six SNPs were linked with GPC under water-deficit conditions only. Moreover, 10 SNPs were linked with GPC under both well-watered and water-deficit conditions. These results emphasize the importance of using diverse, worldwide germplasm to dissect the genetic architecture of GPC in wheat and identify accessions that might be potential parents for high GPC in wheat breeding programs. Full article
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Open AccessCommunication Two Rye Genes Responsible for Abnormal Development of Wheat–Rye Hybrids Are Linked in the Vicinity of an Evolutionary Translocation on Chromosome 6R
Received: 25 May 2018 / Revised: 1 July 2018 / Accepted: 6 July 2018 / Published: 10 July 2018
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Abstract
The post-zygotic reproductive isolation (RI) in plants is frequently based on the negative interaction of the parental genes involved in plant development. Of special interest is the study of such types of interactions in crop plants, because of the importance of distant hybridization
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The post-zygotic reproductive isolation (RI) in plants is frequently based on the negative interaction of the parental genes involved in plant development. Of special interest is the study of such types of interactions in crop plants, because of the importance of distant hybridization in plant breeding. This study is devoted to map rye genes that are incompatible with wheat, determining the development of the shoot apical meristem in wheat–rye hybrids. Linkage analysis of microsatellite loci, as well as genes of embryo lethality (Eml-R1) and hybrid dwarfness (Hdw-R1) was carried out in hybrids of Chinese Spring wheat with recombinant inbred lines as well as interline rye hybrids. Eml-R1 and Hdw-R1 could be mapped proximal and distal of two closely linked EST-SSR markers, Xgrm902 and Xgrm959, on rye chromosome 6R. Both rye genes are located on a segment of chromosome 6R that contains a breakpoint of evolutionary translocation between the ancestral chromosomes of homeologous groups 6 and 3. The obtained results are discussed in relation to genes interacting in developmental pathways as a class of causal genes of RI. Full article
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Open AccessReview Effect of Silicon Fertilization on Crop Yield Quantity and Quality—A Literature Review in Europe
Received: 29 March 2018 / Revised: 3 July 2018 / Accepted: 4 July 2018 / Published: 6 July 2018
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Abstract
This paper presents a research review of the effect of silicon fertilization on the yield quantity and quality in the last 15 years. The study focuses on plant species grown in Europe: cereals, soybean, rapeseed, sugar beet, potato, meadows, berries and vegetables, and
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This paper presents a research review of the effect of silicon fertilization on the yield quantity and quality in the last 15 years. The study focuses on plant species grown in Europe: cereals, soybean, rapeseed, sugar beet, potato, meadows, berries and vegetables, and orchard and ornamental plants. The use of silicon is most common in the production of vegetables in greenhouses. However, the use of this element for the fertilization of agricultural plants is rare. Positive prospects of silicon fertilization are associated with foliar application, which is much cheaper and more convenient to use than soil fertilization. Foliar application of silicon has a biostimulative effect, and the best results are observed in stressful conditions for plants such as salinity, deficiency or excess of water, high and low temperature, and the strong pressure of diseases and pests, etc. Based on the results of previous studies, it can be concluded that foliar nutrition should be introduced into production as a standard treatment in the crop management of many species of agricultural plants. It can help farmers to increase the yield of crops. It is also important that it is safe for the environment, which is particularly important in Europe. Full article
(This article belongs to the Special Issue Practical Use of Si to Influence Plant Production)
Open AccessArticle Exploring Microtubule-Dependent Cellulose-Synthase-Complex Movement with High Precision Particle Tracking
Received: 16 June 2018 / Revised: 2 July 2018 / Accepted: 3 July 2018 / Published: 4 July 2018
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Abstract
Cellulose synthesis at the plasma membrane is a critical process in plant growth and development. The displacement of cellulose synthase complexes (CSCs) by the rigid cellulose polymers they produce is a measure of enzyme activity. Connections between cortical microtubules and CSCs have been
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Cellulose synthesis at the plasma membrane is a critical process in plant growth and development. The displacement of cellulose synthase complexes (CSCs) by the rigid cellulose polymers they produce is a measure of enzyme activity. Connections between cortical microtubules and CSCs have been identified but it remains unclear how these affect CSC displacement speed. In this study, we applied a high throughput automated particle tracking method using near-total internal reflection fluorescence microscopy to measure the speed of CSCs. We found CSC speeds did not vary according to their proximity to microtubules, and that inhibiting microtubule polymerization could have opposite effects on CSC speed, depending on the nature of inhibition. While CSC speed increased in the temperature-sensitive mor1-1 mutant, it decreased after treatment with the drug oryzalin. Moreover, introducing the mor1-1 mutation into the CesA1 mutant any1 increased CSC speed, suggesting that microtubule dynamics affect CSC speed by a mechanism other than Cellulose Synthase A (CesA) catalytic activity. CSC speed varied widely in a range of mutants with reduced growth anisotropy, indicating that the relationship between CSC speed and anisotropy is complex. We conclude that microtubules affect CSC speed by finely tuned mechanisms that are independent of their physical association with CSCs. Full article
(This article belongs to the Special Issue Plant Cell Wall Dynamics in Plant Growth and Stress Response)
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Open AccessReview Phosphoregulation of the Plant Cellulose Synthase Complex and Cellulose Synthase-Like Proteins
Received: 5 June 2018 / Revised: 26 June 2018 / Accepted: 26 June 2018 / Published: 29 June 2018
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Abstract
Cellulose, the most abundant biopolymer on the planet, is synthesized at the plasma membrane of plant cells by the cellulose synthase complex (CSC). Cellulose is the primary load-bearing polysaccharide of plant cell walls and enables cell walls to maintain cellular shape and rigidity.
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Cellulose, the most abundant biopolymer on the planet, is synthesized at the plasma membrane of plant cells by the cellulose synthase complex (CSC). Cellulose is the primary load-bearing polysaccharide of plant cell walls and enables cell walls to maintain cellular shape and rigidity. The CSC is comprised of functionally distinct cellulose synthase A (CESA) proteins, which are responsible for synthesizing cellulose, and additional accessory proteins. Moreover, CESA-like (CSL) proteins are proposed to synthesize other essential non-cellulosic polysaccharides that comprise plant cell walls. The deposition of cell-wall polysaccharides is dynamically regulated in response to a variety of developmental and environmental stimuli, and post-translational phosphorylation has been proposed as one mechanism to mediate this dynamic regulation. In this review, we discuss CSC composition, the dynamics of CSCs in vivo, critical studies that highlight the post-translational control of CESAs and CSLs, and the receptor kinases implicated in plant cell-wall biosynthesis. Furthermore, we highlight the emerging importance of post-translational phosphorylation-based regulation of CSCs on the basis of current knowledge in the field. Full article
(This article belongs to the Special Issue Plant Cell Wall Dynamics in Plant Growth and Stress Response)
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Open AccessViewpoint Genome Editing Weds CRISPR: What Is in It for Phytoremediation?
Received: 28 March 2018 / Revised: 26 June 2018 / Accepted: 26 June 2018 / Published: 28 June 2018
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Abstract
The arrival of sequence-specific endonucleases that allow genome editing has shaken the pillars of basic and applied plant biology. Clustered regularly interspaced palindromic repeats (CRISPR) is a revolutionary genome-engineering tool that enables the enhancement of targeted traits in plants. Numerous plants, including energy
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The arrival of sequence-specific endonucleases that allow genome editing has shaken the pillars of basic and applied plant biology. Clustered regularly interspaced palindromic repeats (CRISPR) is a revolutionary genome-engineering tool that enables the enhancement of targeted traits in plants. Numerous plants, including energy crops, known for their potential to tolerate, immobilize, and stabilize inorganic and organic pollutants, have already been edited using different CRISPR systems. Moreover, a large array of genes responsible for increased metal tolerance, metal uptake and hyperaccumulation have already been identified. Thus, the CRISPR-mediated genome reprogramming of plants, including its use in gene expression regulation through transcriptional repression or activation (CRISPRi and CRISPRa), could be of paramount importance for phytoremediation. The simplicity, inexpensiveness, and capabilities of this gene editing technique could soon be used to enhance plants and bacteria involved in phytotechnologies, such as phystabilization, phytoextraction, phytomining, phytovolatilization, and bio-energy generation. In this brief viewpoint piece, we posit some of the potential benefits of CRISPR for phytoremediation. Full article
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Open AccessArticle Genome-Wide Identification and Expression Analyses of the Fibrillin Family Genes Suggest Their Involvement in Photoprotection in Cucumber
Received: 31 May 2018 / Revised: 15 June 2018 / Accepted: 23 June 2018 / Published: 27 June 2018
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Abstract
Fibrillin (FBN) is a plastid lipid-associated protein found in photosynthetic organisms from cyanobacteria to plants. In this study, 10 CsaFBN genes were identified in genomic DNA sequences of cucumber (Chinese long and Gy14) through database searches using the conserved domain of FBN and
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Fibrillin (FBN) is a plastid lipid-associated protein found in photosynthetic organisms from cyanobacteria to plants. In this study, 10 CsaFBN genes were identified in genomic DNA sequences of cucumber (Chinese long and Gy14) through database searches using the conserved domain of FBN and the 14 FBN genes of Arabidopsis. Phylogenetic analysis of CsaFBN protein sequences showed that there was no counterpart of Arabidopsis and rice FBN5 in the cucumber genome. FBN5 is essential for growth in Arabidopsis and rice; its absence in cucumber may be because of incomplete genome sequences or that another FBN carries out its functions. Among the 10 CsaFBN genes, CsaFBN1 and CsaFBN9 were the most divergent in terms of nucleotide sequences. Most of the CsaFBN genes were expressed in the leaf, stem and fruit. CsaFBN4 showed the highest mRNA expression levels in various tissues, followed by CsaFBN6, CsaFBN1 and CsaFBN9. High-light stress combined with low temperature decreased photosynthetic efficiency and highly induced transcript levels of CsaFBN1, CsaFBN6 and CsaFBN11, which decreased after 24 h treatment. Transcript levels of the other seven genes were changed only slightly. This result suggests that CsaFBN1, CsaFBN6 and CsaFBN11 may be involved in photoprotection under high-light conditions at low temperature. Full article
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Open AccessArticle Axial and Radial Spatial Patterns of Non-Structural Carbohydrates in Cycas micronesica Stems
Received: 11 June 2018 / Revised: 20 June 2018 / Accepted: 21 June 2018 / Published: 22 June 2018
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Abstract
The pachycaulous stem of arborescent cycad species exhibits unique traits and has received limited research. To date, nothing is known about the axial and radial spatial patterns of non-structural resources within cycad stems. Cycas micronesica K.D. Hill stem tissue was collected from apical
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The pachycaulous stem of arborescent cycad species exhibits unique traits and has received limited research. To date, nothing is known about the axial and radial spatial patterns of non-structural resources within cycad stems. Cycas micronesica K.D. Hill stem tissue was collected from apical and basal axial positions of ca. 100-cm tall plants to serve as two axial regions; and from pith, vascular, and cortex tissues to serve as three radial regions. Starch and four free sugars were quantified. These stems contained more starch than any of the individual sugars, and sucrose concentration exceeded that of fructose and glucose, which exceeded that of maltose. Total non-structural carbohydrate was least in basal vascular tissue (225 mg·g−1) and greatest in apical pith tissue (379 mg·g−1). Axial differences in NSC concentrations were negligible but radial differences were substantial. These results combine with past research to validate the non-woody cycad stem contains copious nonstructural resources available for deployment to ephemeral sinks during critical times of need. Full article
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Open AccessArticle Determination of the Water Potential Threshold at Which Rice Growth Is Impacted
Received: 26 April 2018 / Revised: 18 May 2018 / Accepted: 23 May 2018 / Published: 22 June 2018
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Abstract
Rice feeds 50% of the world’s population. Flooding is the most common irrigation system used for growing rice, a practice responsible for a large amount of water loss. Climate changes may affect water availability in irrigated agriculture, and it will be necessary to
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Rice feeds 50% of the world’s population. Flooding is the most common irrigation system used for growing rice, a practice responsible for a large amount of water loss. Climate changes may affect water availability in irrigated agriculture, and it will be necessary to develop more sustainable irrigation practices. The aim of this work was to determine, in controlled conditions, the threshold when water potential begins to decrease plant growth. Two independent greenhouse experiments were conducted during middle summer and fall, in order to validate the results for high and low evapotranspiration conditions. Rice plants were grown in hydroponics and the water potential was adjusted with polyethylene glycol 6000, varying from −0.04 MPa (control) to −0.19 MPa. Leaf water potential, water use efficiency, leaf area, and root and shoot biomass were evaluated. All assayed parameters decreased as the water potential was decreased. The water potential threshold which starts to negatively affect rice growth was between −0.046 and −0.056 MPa, which are values close to those observed in the field in previous research. The definition of a critical value may help to improve water management in rice cultivation and to maintain productivity. Full article
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