Project description:Plant drought stress response and resistance are complex biological processes that merit systems-level analyses to dissect drought stress encountered by crops in the field. We have used gene expression profiling of Arabidopsis plants subjected to a controlled, sublethal, moderate drought (mDr) treatment to characterize early and late response to drought. We have also compared these profiles to those from plants treated with soil water deficit (progressive) drought (pDr) to reveal acclimation responses in plants.
Project description:In this work, we performed high throughput sequencing of small RNA libraries in maize (Zea mays ssp. mays) and teosinte (Zea mays ssp. parviglumis) to investigate the response mediated by miRNAs in these plants under control conditions, submergence, drought and alternated drought-submergence or submergence-drought stress. After Illumina sequencing of 8 small RNA libraries, we obtained from 16,139,354 to 46,522,229 raw reads across the libraries. Bioinformatic analysis identified 88 maize miRNAs and 76 miRNAs from other plants differentially expressed in maize and/or in teosinte in response to at least one of the treatments, and revealed that a larger set of miRNAs were regulated in maize than in teosinte in response to submergence and drought stress.
Project description:Plants have evolved a sophisticated defense system to survive under natural drought conditions. MicroRNAs (miRNA) are small noncoding RNAs that act as a post-transcriptional regulator in the environmental stress response and developmental process. Although many studies have reported the involvement of the miRNAs in drought response, molecular mechanisms by which miRNAs confer drought tolerance remain elusive. Here, we show that MIR171f, a member of MIR171 gene family, is mainly expressed in response to drought stress and regulate transcript levels of SCARECROW-LIKE6-I (SCL6-I) and SCL6-II. The SCL6 genes are known to be involved in shoot branching and flag leaf morphology. The MIR171f-overexpressing (MIR171f-OE) transgenic plants showed reduced drought symptoms as compared with non-transgenic (NT) control plants under both field drought and PEG-mediated dehydration stress conditions. Transcriptome analysis using the MIR171f-OE and mir171f-K/O mutants revealed that MIR171f regulates the expression of flavonoid biosynthesis genes, consequently leading to drought tolerance. Flavonoid biosynthesis genes were up-regulated in MIR171f-OE plants as compared with NT control plants under both normal and drought conditions. Together, our findings demonstrated that MIR171f plays an important role in plant drought-tolerance mechanism by regulating transcript levels of SCL6-I and SCL6-II.
Project description:As a major plant abiotic stress, drought stress suppresses crop yield performance severely. However, the trade-off between crop drought tolerance and yield performance becomes a great challenge in drought-resistant crop breeding. Several phytohormones have been reported to participate in plant drought response, including gibberellin (GA), which also plays an important role in plant growth and development. Using CRISPR technology, we constructed the null mutant of ZmGA20ox3, a key enzyme in GA biosynthesis. The null mutant plants show lower plant height and ear height with no yield loss under the normal condition than wild-type plants. Transcriptome analysis revealed that genes affected by ZmGA20ox3 were enriched in signal transduction and stress response processes. In addition to the decrease of GA, a significant increase of ABA and JA level were also detected in mutant plants. Compared with wild-type plants, the growth and ASI of mutant plants were less affected, and the yield loss was also reduced under drought conditions. These results suggest a potential role of ZmGA20ox3 in maize drought response. Our result shows that regulating GA biosynthesis is applicable for maize drought-resistant breeding.
Project description:ra06-02_staygreen - drought and salt stress response - Modification of the transcriptome by the eskimo mutation and response to stress. - Individual plants were grown in Fertiss clods in a culture chamber. 3 treatments were made to the plants : control, drought and salt. Keywords: gene knock out,treated vs untreated comparison
Project description:External application of acetic acid has been recently reported to enhance the survival to drought in plants such as Arabidopsis, rapeseed, maize, rice and wheat, but the effects of acetic acid application on increased drought tolerance in woody plants such as a tropical crop “cassava” remain elusive. A molecular understanding of acetic acid-induced drought avoidance in cassava will contribute to the development of technology that can be used to enhance drought tolerance without resorting to transgenic technology or advancements in cassava cultivation. In the present study, morphological, physiological and molecular responses to drought were analyzed in cassava after the treatment with acetic acid. Results indicated that the acetic acid-treated cassava plants had a higher level of drought avoidance than water-treated, control plants. Specifically, higher leaf relative water content, and chlorophyll and carotenoid levels were observed as soils dried out during the drought treatment. Leaf temperatures in acetic acid-treated cassava plants were higher relative to leaves on plants pretreated with water and the increase of ABA content was observed in leaves of acetic acid-treated plants, suggesting that stomatal conductance and the transpiration rate in leaves of acetic acid-treated plants decreased to maintain relative water contents and avoid drought. Transcriptome analysis revealed that the acetic acid treatment increased the expression of ABA signaling-related genes, such as OPEN STOMATA 1 (OST1) and protein phosphatase 2C; as well as drought response and tolerance-related genes, such as outer membrane tryptophan-rich sensory protein (TSPO), and heat shock proteins. Collectively, the external application of acetic acid enhances drought avoidance in cassava through the upregulation of ABA signaling pathway genes and several stress response- and tolerance-related genes. These data support the idea that adjustments of the acetic acid application to plants is useful to enhance drought tolerance in order to minimize the growth inhibition in the agricultural field.
Project description:The members of bHLH transcription factor superfamily are known to play key role in plant development and abiotic stress response. Loss-of-function of OsbHLH148 gene resulted in increased sensitivity of rice plants to drought stress. To identify the targets of OsbHLH148 and dissect the drought stress response pathway regulated by it, we performed transcriptome profiling of Osbhlh148 mutant plants under drought stress as well as well-watered conditions by RNA-sequencing.
Project description:Heat shock factors (Hsfs) are known to regulate heat and drought stress response by controlling the expression of heat shock proteins and oxidative stress responsive genes. Loss-of-function of OsHSFA2e gene resulted in increased sensitivity of rice plants to drought and heat stress. To identify the targets of OsHSFA2e and dissect the stress response pathway regulated by it, we performed transcriptome profiling of Oshsfa2e mutant plants under drought stress as well as well-watered conditions by RNA-sequencing.
Project description:In order to increase our understanding on the epigenetic regulation in response to abiotic stresses in plants, sRNA regulation in sugarcane plants submitted to drought stress was analyzed. Deep sequencing analysis was carried out to identify the sRNA regulated in leaves and roots of sugarcane cultivars with different drought sensitivities. An enrichment of 22-nt sRNA species was observed in leaf libraries. The pool of sRNA selected allowed the analysis of different sRNA classes (miRNA and siRNA). Twenty eight and 36 families of conserved miRNA were identified in leaf and root libraries, respectively. Dynamic regulation of miRNA was observed and the expression profile of eight miRNA was verified in leaf samples by stem-loop qRT-PCR assay. Altered miRNA regulation was correlated with changes in mRNA levels of specific targets. 22-nt miRNA triggered siRNA-candidates production by cleavage of their targets in response to drought stress. Some genes of sRNA biogenesis were down-regulated in tolerant genotypes and up-regulated in sensitive in response to drought stress. Our analysis contributes to increase the knowledge on the roles of sRNA in epigenetic-regulatory pathways in sugarcane submitted to drought stress.