Project description:ABSTRACT: Background: Though central to our understanding of how roots perform their vital function of scavenging water and solutes from the soil, no direct genetic evidence currently exists to support the foundational model that suberin acts to form a chemical barrier limiting the extracellular, or apoplastic, transport of water and solutes in plant roots. Methodologies/Principle Findings: Using the newly characterized enhanced suberin1 (esb1) mutant, we established a connection in Arabidopsis thaliana between suberin in the root, and both water movement through the plant, and solute accumulation in the shoot. Esb1 mutants, characterized by increased root suberin, were found to have reduced day time transpiration rates, and increased water use efficiency during their vegetative growth period. Furthermore, these changes in suberin and water transport were associated with decreases in the accumulation of Ca, Mn and Zn, and increases in the accumulation of Na, S, K, As, Se and Mo in the shoot. Conclusions/Significance: Here we present direct genetic evidence establishing that suberin in the roots plays a critical role in controlling both water and mineral ion uptake and transport to the leaves. The changes observed in the elemental accumulation in leaves are also interpreted as evidence that a significant component of the radial root transport of Ca, Mn and Zn occurs in the apoplast. Keywords: genomic hybridization bulked segregant analysis
Project description:Drought and salinity are two main abiotic-stresses negatively affecting crop growth and productivity worldwide with largely decreasing crop yields. The understanding of plant responses to stresses in physiology, genetics, and molecular biology will be greatly helpful to improve the tolerance of crops to abiotic-stresses through genetic engineering.To identify the genetic loci that control drought and salt tolerance in rice, we performed a large-scale screen for the mutants with altered drought and salt tolerance. A drought and salt tolerance (dst) mutant line was isolated.In this series, we compare the transcriptome of wild-type plant Zhonghua11 and dst mutants under the normal growth conditions. Keywords: genetic modification
Project description:Plants possess highly sensitive mechanisms that monitor environmental stress levels for a dose-dependent fine-tuning of their growth and development. Differences in plant responses to severe and mild abiotic stresses have been recognized. Although many studies have revealed that glutathione can contribute to plant tolerance to various environmental stresses, little is known about the relationship between glutathione and mild abiotic stress, especially the effect of stress-induced altered glutathione levels on the metabolism. Here, we applied a systems biology approach to identify key pathways involved in the gene-to-metabolite networks perturbed by low glutathione content under mild abiotic stress in Arabidopsis thaliana. We used glutathione synthesis mutants (cad2-1 and pad2-1) and plants overexpressing the gene encoding gamma-glutamylcysteine synthetase, the first enzyme of the glutathione biosynthetic pathway. The plants were exposed to two mild stress conditions―oxidative stress elicited by methyl viologen (MV) and stress induced by the limited availability of phosphate. We observed that the mutants and transgenic plants showed similar shoot growth as that of the wild-type plants under mild abiotic stress. We then selected the synthesis mutants and performed multi-platform metabolomics and microarray experiments to evaluate the possible effects on the overall metabolome and the transcriptome. To understand the metabolic responses observed under mild abiotic stress, we conducted gene expression profiling by Affymetrix ATH1 GeneChip. pad2-1 and the wild type Col-0 samples were harvested at 18 day-old after germination under two different stresses, MV treatment and limited phosphorus conditions.
Project description:Plants will meet various abiotic stresses during their growth and development. One of the important strategies for plants to deal with the stress is involved in metabolic regulation, causing the dramatic changes of metabolite profiles. Metabolomic studies have been intensively conducted to reveal the responses of plants to abiotic stress, but most of them were limited to one or at most two abiotic stresses in a single experiment. In this study, we compared the metabolite profiles of barley seedlings exposed to seven abiotic stresses simultaneously, including drought, salt stress, aluminum (Al), cadmium (Cd), deficiency of nitrogen (N), phosphorus (P) and potassium (K). The results showed that metabolite profiles of barley under these stresses could be classified into three types: osmotic stresses (drought and salt); metal stresses (Al and Cd) and nutrient deficiencies (N, P and K deficiencies). Compared with the control, some metabolites (including polyamines, raffinose and piperonic acid) in plants exposed to all abiotic stresses changed significantly, while some other metabolites showed the specific change only under a certain abiotic stress, such as proline being largely increased by osmotic stress (drought and salinity), the P-containing metabolites being largely decreased under P deficiency, some amino acids (lysine, tyrosine, threonine, ornithine, glutamine and so on) showing the dramatic reduction in the plants exposed to N deficiencies, respectively. The current meta-analysis obtained a comprehensive view on the metabolic responses to various abiotic stress, and improved the understanding of the mechanisms for tolerance of barley to abiotic stress.
Project description:To identify novel miRNA and NAT-siRNAs that are associated with abiotic stresses in sorghum, we generated small RNA sequences from sorghum seedlings that grew under control and under dought, salt, and cold stress treatments.
Project description:To identify novel miRNA and NAT-siRNAs that are associated with abiotic stresses in maize, we generated small RNA sequences from maize seedlings that grew under control and under dought, salt, and cold stress treatments.
Project description:Drought and salinity are two main abiotic-stresses negatively affecting crop growth and productivity worldwide with largely decreasing crop yields. The understanding of plant responses to stresses in physiology, genetics, and molecular biology will be greatly helpful to improve the tolerance of crops to abiotic-stresses through genetic engineering. To identify the genetic loci that control drought and salt tolerance in rice, we performed a large-scale screen for the mutants with altered drought and salt tolerance. A drought and salt tolerance (dst) mutant line was isolated. In this series, we compare the transcriptome of wild-type plant Zhonghua11 and dst mutants under the normal growth conditions. Keywords: genetic modification 6 samples (3 biological replicates for each line) were used in this experiment.
Project description:Phosphate limitation constrains plant development in natural and agricultural systems. Under phosphate-limiting conditions plants activate genetic, biochemical and morphological modifications to cope with phosphate starvation. One of the morphological modifications that plants induce under phosphate limitation is the arrest of primary root growth and it is induced by the root tip contact with low phosphate media. The sensitive to proton rhizotoxicity (stop1) and aluminium activate malate transporter 1 (almt1) mutants of Arabidopsis thaliana continue primary root growth under in vitro Pi-limiting conditions, thus, to get insight into the molecular components that control primary root growth inhibition under low phosphate conditions we extracted and sequenced mRNA from the root tips (2-3 mm from the root apex) of wild-type plants (Col-0 accession) and low-phosphate-insensitive mutants almt1 and stop1 grown under low and high phosphate conditions 5 days after germination using an RNA-seq methodology.
Project description:Alkali stress is one of the most severe abiotic stresses affecting agricultural production worldwide. To understand the phosphorylation events in soybean in response to alkali stress, we performed the TMT labeling-based quantitative phosphoproteomic analyses on soybean leaf and root tissues under 50 mM NaHCO3 treatment.
Project description:To identify novel miRNA and NAT-siRNAs that are associated with abiotic stresses in rice, we generated small RNA sequences from inflorescences from rice under control and under dought, salt, and cold stress treatments. Over 30 million reads were generated.