Project description:The global emergence of soil salinization poses a serious challenge to many countries and regions. γ-Aminobutyric acid (GABA) is involved in systemic regulation of plant adaptation to salt stress, but the underling molecular and metabolic mechanism still remains largely unknown. The elevated endogenous GABA level by exogenous application of GABA could significantly improve salt tolerance in creeping bentgrass with the enhancement of antioxidant capacity, photosynthetic characteristics, osmotic adjustment (OA), and water use efficiency. GABA strongly upregulated transcript levels of AsPPa2, AsATPaB2, AsNHX2/4/6, and AsSOS1/20 in roots involved in enhanced capacity of Na+ compartmentalization and mitigation of Na+ toxicity in cytosol. Significant downregulation of AsHKT1/4 expression could be induced by GABA in leaves in relation to maintenance of significantly lower Na+ accumulation and higher K+/Na+ ratio. GABA-depressed aquaporins (AQPs) expression and accumulation induced declines in stomatal conductance and transpiration, thereby reducing water loss in leaves during salt stress. For metabolic regulation, GABA primarily enhanced sugars and amino acids accumulation and metabolism largely contributing to improved salt tolerance through maintaining OA and metabolic homeostasis. Other major pathways could be responsible for GABA-induced salt tolerance including increases in antioxidant defense, heat shock proteins, dehydrins, and myo-inositol accumulation in leaves. Integrative analyses of molecular, protein, metabolic, and physiological changes reveal systemic function of GABA on regulating ions, water, and metabolic homeostasis in non-halophytic creeping bentgrass under salt stress.
Project description:Transcriptome sequencing (RNA-seq) was used to profile genome-wide transcript abundance in the primary root growth zone (PRGZ) of maize seedlings grown in different water deficit treatments: well-watered (-0.02 MPa), mild water deficit stress (-0.3 MPa), or severe water deficit stress (-1.6 MPa). For each water deficit treatment, the PRGZ transcriptome was profiled at 26 hours after initiation of the water deficit treatment. By comparing the abundance of each transcript under mild or severe water deficit stress relative to its abundance under well-watered conditions, we identified transcripts that are differentially regulated in the PRGZ in response to the two levels of water deficit stress.
Project description:These microarrays are part of a study where a comparison was made between the change in transcription and H3K4 mono-, di-, and tri-methylation levels (via ChIP-seq) in the Arabidopsis thaliana genome when plants are subjected to water deficit stress. Water deficit stress causes a large number of genes to change their transcript levels, which provided a large set of genes to examine for corresponding chromatine changes. Keywords: stress response
Project description:These microarrays are part of a study where a comparison was made between the change in transcription and H3K4 mono-, di-, and tri-methylation levels (via ChIP-seq) in the Arabidopsis thaliana genome when plants are subjected to water deficit stress. Water deficit stress causes a large number of genes to change their transcript levels, which provided a large set of genes to examine for corresponding chromatine changes. Keywords: stress response Arabidopsis thaliana RNA was isolated from control (watered) and treatment (water-deficit) samples for analysis on microarrays with three biological reps.
Project description:Soybean plants were subjected to water deficit, heat stress, and combination of water deficit and heat stress along with control condition and pods were analysed for temperature, water potential, transpiration, yield and differential gene expression compared to control.
Project description:By sequencing 36 cDNA libraries with Illumina technology, we identified genes differentially expressed in soybean plants in response to water deficit and genes that were either up- or down-regulated in different periods of the day. Of 54,175 predicted soybean genes (Glyma v1.1), 35.52% exhibited expression oscillations in a 24 h period. This number increased to 39.23% when plants were submitted to water deficit. Major differences in gene expression were observed in the control plants from late day (ZT16) until predawn (ZT20) periods, indicating that gene expression oscillates during the course of 24 h in normal development. Under water deficit, dissimilarity increased in all time-periods, indicating that the applied stress influenced gene expression. Results suggest that time of day, as well as light and temperature oscillations that occur considerably affect the regulation of water deficit stress response in soybean plants.
Project description:Background: MicroRNAs are endogenous small noncoding RNAs that play critical roles in plant abiotic stress responses. The interaction between miRNA-mRNA targets and their regulatory pathways in response to water deficit stress has been investigated in many plant species. However, the miRNA transcriptome of durum wheat (Triticum turgidum L. ssp. durum) is poorly characterised, with little known about miRNA functions related to water deficit stress. Yield loss in durum wheat can be exacerbated due to minimal rainfall in the early reproductive stages of development during Spring in Australia. This study describes genotypic differences in the miRNAome between water deficit tolerant/sensitive durum, using flag leaf and developing head tissue, and more specifically identifies miRNAs associated with water deficit stress. Results: Small RNA libraries (96 in total) were constructed from flag leaf and developing head tissues of four durum genotypes (Tamaroi, Yawa, EGA Bellaroi, Tjilkuri), with or without water deficit stress. Illumina sequencing and subsequent analysis detected 110 conserved miRNAs and 159 novel candidate miRNA hairpins. Statistical analysis of the abundance of sequencing reads revealed 66 conserved miRNAs and five novel miRNA hairpins showing differential expression under water deficit stress. During stress, several conserved and novel miRNAs showed unambiguous inverted regulatory profiles between the durum genotypes studied. Several miRNAs were also identified to have different abundance in the flag leaf compared to the developing head regardless of treatment. Predicted mRNA targets from four novel durum miRNAs were characterised using Gene Ontology (GO) which revealed functions common to stress responses and plant development. Conclusion: For the first time, we present a comprehensive study of the miRNA transcriptome of flag leaf and developing head tissues in different durum genotypes under water deficit stress. The identification of differentially expressed miRNAs provides molecular evidence that miRNAs are potential determinants of water stress tolerance in durum wheat. GO analysis of predicted targets contributes to the understanding of genotype-specific physiological responses leading to stress tolerance capacity. Further functional analysis of specific stress responsive miRNAs identified, and their interaction with mRNA targets is ongoing and will assist in developing future durum wheat varieties with enhanced water deficit stress tolerance.
Project description:Soybean plants were subjected to water deficit, heat stress, and combination of water deficit and heat stress along with control condition for 10 days and unopened soybean buds were analysed for differential gene expression compared to control.
Project description:By sequencing 36 cDNA libraries with Illumina technology, we identified genes differentially expressed in soybean plants in response to water deficit and genes that were either up- or down-regulated in different periods of the day. Of 54,175 predicted soybean genes (Glyma v1.1), 35.52% exhibited expression oscillations in a 24 h period. This number increased to 39.23% when plants were submitted to water deficit. Major differences in gene expression were observed in the control plants from late day (ZT16) until predawn (ZT20) periods, indicating that gene expression oscillates during the course of 24 h in normal development. Under water deficit, dissimilarity increased in all time-periods, indicating that the applied stress influenced gene expression. Results suggest that time of day, as well as light and temperature oscillations that occur considerably affect the regulation of water deficit stress response in soybean plants. Gene expression analysis of soybean leaves under water deficit in 6 periods of day by sequencing 36 libraries, in triplicate, in Illumina platform.