Project description:In this study, we used the illumina high throughput sequencing approach (Sequencing-By-Synthesis, or SBS) to develop the sequence resource of black pepper. To identify micro RNAs functioning in stress response of the black pepper plant, small RNA libraries were prepared from the leaf and root of Phytophthora capsici infected plants, leaves from drought stressed and control plants.
Project description:Seven different Solanaceae species, Potato (Solanum tubersosum), Tomato (Solanum lycopersicum), Eggplant (Solanum melongena), Pepper (Capsicum annuum), Tobacco (Nicotiana tabaccum), Petunia and Nicotiana benthiamana were subjected to drought stress. Drought stress was applied by stopping watering of the plants, control plants were normally watered with nutrient solution. Samples were collected at 0, 1, 3, 5, 7 and 10 days after the first application of the drought stress. RNA was isolated using Qiagen RNeasy. Keywords: Direct comparison
Project description:Drought is one of the major factor that limits crop production and reduces yield. To understand the early response of plants under nearly natural conditions, pepper plants were grown in a greenhouse and drought stressed by withholding water for one week. Plants adapted to the decreasing water content of the substrate by adjustment of their osmotic potential in roots by accumulation of raffinose, glucose, galactinol and proline. In contrast in leaves levels of fructose, sucrose and also galactinol increased. Due to the water deficit cadaverine, putrescine, spermidine and spermine accumulated in leaves whereas the concentration of polyamines was reduced in roots. These polyamines are suggested to rather act as stress protectants than for osmotic adjustment. To understand the molecular basis of the response to this early drought stress better, four suppression subtractive hybridisation libraries from leaves and roots were constructed. Microarray technique was used to identify differentially expressed genes. A total of 109 unique ESTs were detected. The diversity of the putative functions of all identified genes confirms the complexity of the plant response to drought stress. Keywords: Transcription profiling Two-condition experiment in roots and leaves, control leaves (CL) vs. drought-stressed leaves (DL) and control roots (CR) vs. drought-stressed roots (DR). Biological replicates: 4 control (1-4), drought-stressed (1-4), independently grown and harvested. One swap replicate per array.
Project description:Drought is one of the major factor that limits crop production and reduces yield. To understand the early response of plants under nearly natural conditions, pepper plants were grown in a greenhouse and drought stressed by withholding water for one week. Plants adapted to the decreasing water content of the substrate by adjustment of their osmotic potential in roots by accumulation of raffinose, glucose, galactinol and proline. In contrast in leaves levels of fructose, sucrose and also galactinol increased. Due to the water deficit cadaverine, putrescine, spermidine and spermine accumulated in leaves whereas the concentration of polyamines was reduced in roots. These polyamines are suggested to rather act as stress protectants than for osmotic adjustment. To understand the molecular basis of the response to this early drought stress better, four suppression subtractive hybridisation libraries from leaves and roots were constructed. Microarray technique was used to identify differentially expressed genes. A total of 109 unique ESTs were detected. The diversity of the putative functions of all identified genes confirms the complexity of the plant response to drought stress. Keywords: Transcription profiling
Project description:We have characterized the changes in miRNA expression profiles in rice leaves under drought stress and As stress and compared these to unstressed leaves. 10 pairs of drought responsive and 8 pairs of As responsive miRNA-gene were identified and validated by qRT-PCR. This study identifies putative specific miRNA-mRNA regulatory modules with roles during drought and As stress. Putative microRNAs identified in this study are involved in hormone signaling, lipid and carbohydrate metabolism, and antioxidant defence. The results of this study will assist in elucidating the role of miRNAs in post-transcriptional regulation of target genes during abiotic stress and may contribute to the development of strategies to engineer drought and heavy metal resistance.
Project description:Drought stress response involves vigorous reprogramming of transcriptome while the mechanism modulating this process remains elusive. The role of 3D-genome in the regulation of rice development has recently been unveiled in rice, which exhibited characteristics distinct from that in mammals and other plants. However, the relationship between spatial chromosome organization and drought responsive gene reprogramming is still poorly understood. In this study, we identified H3K9ac as an efficient histone mark that response dynamically to drought stress in rice and re-constructed high-resolution 3D genome contact maps based on these sites under the normal, drought, and recovery conditions. We discovered significant decondensation of chromatin contacts with over 10000 chromatin loops lost upon drought stress treatment while the recovery of 3D genome was limited after 4-day’s re-watering. We identified dominate promoter-promoter interacting (PPI) loops under each condition and identified their significant correlations to altered gene expressions in response to the corresponding condition. Based on the relative contact intensities of the PPI connections, we characterized super-promoter regions that integrate closer connections of genes with more vigorous inductions to condition shifts. Especially, about 75% of the drought stress-dominate PPI loops were associated to the binding by a well-defined drought stress-responsive transcription factor, OsbZIP23. The mutation of OsbZIP23 led to the diffuse of over 80% DS-dominate PPI loops and impaired the expression of the connected genes. As a case study, we showed how OsbZIP23 binding to a super-promoter region can integrate the PPI loop formation and transcriptional activation of four function-vital dehydrin genes upon drought stress. Our results shed light on the mechanisms of 3D genome dynamic in response to water supply variations in rice and highlight the role of OsbZIP23 in the regulation of chromatin loop formation under drought stress.
Project description:To better undersand the effects of drought stress on wheat developing seeds, the transcription profile of early developing wheat seeds under control and drought stress conditions were comparatively analyzed by using the Affymetrix wheat geneChip. Drought stress is a major yield-limiting factor for wheat. Wheat yields are particularly sensitive to drought stress during reproductive development. Early seed development stage is an important determinant of seed size, one of the yield components. We specifically examined the impact of drought stress imposed during postzygotic early seed development in wheat. We imposed a short-term drought stress on plants with day-old seeds and observed that even a short-duration drought stress significantly reduced the size of developing seeds as well as mature seeds. Drought stress delayed the developmental transition from syncytial to cellularized stage of endosperm. Coincident with reduced seed size and delayed endosperm development, a subset of genes associated with cytoskeleton organization was misregulated in developing seeds under drought-stressed. Several genes linked to hormone pathways were also differentially regulated in response to drought stress in early seeds. Notably, drought stress strongly repressed the expression of wheat storage protein genes such as gliadins, glutenins and avenins as early as 3 days after pollination. Our results provide new insights on how some of the early seed developmental events are impacted by water stress, and the underlying molecular pathways that can possibly impact both grain size and quality in wheat.
Project description:Two hundreds eighty three and 293 known miRNAs were identified from the control and drought stress libraries, respectively. In addition, 253 potential candidate miRNAs were identified, and among them 48 novel miRNAs/ novel members of known miRNA families whose complementary miRNAs were also detected. Both high-throughput sequencing and RT-qPCR confirmed that 22 members of 4 miRNA families were up-regulated and 10 members of 6 miRNA families were down-regulated in response to drought stress. Among the 48 novel miRNAs, 24 miRNAs were responsive to drought stress with 21 and 3 miRNAs being up- and down-regulated, respectively. The known and predicted targets of these miRNAs in response to drought stress are involved in diverse cellular processes in plants, such as development, transcription, protein degradation, detoxification, nutrient status and cross adaptation.