Project description:To unravel the molecular mechanisms underpinning Codonopsis pilosula drought stress tolerance, we conducted comprehensive comparative transcriptome and physiological analyses of two C. pilosula cultivars that had been exposed to drought treatment for four days.
Project description:OsNAC6 is a stress responsive NAC transcription factor in rice known as a regulator for the transcriptional networks of the drought tolerance mechanisms. However, little is known about the associated molecular mechanisms for drought tolerance. Here, we identified OsNAC6-mediated root structural adaptation such as increased root number and root diameter that was sufficient to confer drought tolerance. Multiyear (5 years) drought field tests clearly demonstrated that OsNAC6 overexpression in roots produced higher grain yield under drought conditions. Genome-wide analyses revealed that OsNAC6 directly up-regulated 13 genes. Taken together, OsNAC6 is a valuable candidate for genetic engineering of drought-tolerant high-yielding crops.
Project description:Integrated breeding strategies are used to increase both the yield potential and stability of crops. Most of these approaches have a direct genetic basis. The utility of epigenetics in breeding to improve complex traits such as yield and stress tolerance is not clear. A better understanding of the status of the epigenome and its contribution to the agronomic performance would help in developing strategies to incorporate the epigenetic component of complex traits in breeding,Starting from isogenic canola lines, epilines were generated by selecting recursively during three generations for lines with a higher energy use efficiency and drought tolerance. These epilines were more energy use efficient, drought tolerant, high nitrogen use efficient, and higher yielding under suboptimal conditions. Moreover, these characteristics were transgenerational inheritable. Transcriptome comparison with a line selected for energy use efficiency only revealed common differentially expressed genes related to the onset of signaling events regulating stress tolerance. Genes related to salt, osmotic, abscisic acid and drought were specifically differentially expressed in the drought tolerant epilines. The status of the epigenome, scored as differential trimethylation of lysine 4 of histone 3, supports the energy use efficient and drought tolerant phenotype by facilitating transcription of the genes that are found to be differentially expressed.From these results it can be concluded that the epigenome can be shaped by selection to increase yield and stress tolerance. This acquired knowledge will support further development of strategies to incorporate epigenetics in breeding. To investigate the epigenetic effect on histone mark distribution of the EUE/PEG selection we performed ChIP-seq analyses. Native ChIP using an anti-H3K4me3 and no antibody (background control) was done on PEG1 and control plants.
Project description:The drought stress is one of key adverse environmental factors limiting plant growth and development, even threating global crop productivity in many arid and semi-arid regions. Drought stress usually causes huge economic losses for tobacco industries. Understanding how plants respond and adapt to the drought stress helps generate engineered plants with enhanced drought resistance. In this study, integrative analyses of multiple time point-related transcriptome and metabolome generated from K326 and its derived mutant 28 (M28) with contrasting drought tolerance. We found that dramatic changes of gene expression profiles between M28 and K326 before and after drought treatment.
Project description:OsNAC6 is a stress responsive NAC transcription factor in rice known as a regulator for the transcriptional networks of the drought tolerance mechanisms. However, little is known about the associated molecular mechanisms for drought tolerance. Here, we identified OsNAC6-mediated root structural adaptation such as increased root number and root diameter that was sufficient to confer drought tolerance. Multiyear (5 years) drought field tests clearly demonstrated that OsNAC6 overexpression in roots produced higher grain yield under drought conditions. Genome-wide analyses revealed that OsNAC6 directly up-regulated 13 genes. Taken together, OsNAC6 is a valuable candidate for genetic engineering of drought-tolerant high-yielding crops.
Project description:Plant stress response and tolerance mechanisms are controlled by diverse genes. Transcription factors have been implicated in drought tolerance under drought stress conditions. Identification of target genes of such transcription factors could offer molecular regulatory networks by which the tolerance mechanisms orchestrated. Previously, we generated transgenic rice plants with 4 rice transcription factors OsNAC5, 6, 9, and 10 under the root-specific promoter RCc3 that were tolerant to drought stress with less loss of grain yield under drought conditions. To understand the molecular mechanisms of drought tolerance, we performed ChIP-Seq and RNA-Seq analyses to identify direct target genes of the OsNACs using the RCc3:MYC-OsNACs roots. A total of 475 binding loci of 4 OsNACs were identified by cross-referencing the binding occupancy of OsNACs at promoter regions and expression levels of corresponding genes. The binding loci are distributed on promoter regions of 391 target genes that were directly up-regulated by OsNACs in four RCc3:MYC-OsNAC transgenic roots. The direct target genes were related to transmembrane/transporter activity, vesicle, plant hormone, carbohydrate metabolism, and transcription factors. The direct targets of each OsNAC are in a range of 4.0 to 8.7% of the genes up-regulated in RNA-Seq data sets. Thus, each OsNAC up-regulates of corresponding direct target genes that alters root system architectures of RCc3:OsNACs for drought tolerance. Our results provide valuable resources for functional dissection of the molecular mechanisms for plant drought tolerance.
Project description:Spider silk, especially dragline silk from Trichonephila clavipes, is an excellent natural material with remarkable mechanical properties. In this study, we generated nucleus- and plastid-encoded expression of a partial sequence of one of the components of dragline silk, major ampullate spidroin-1 (MaSp1), in tobacco (MaSp1-tobacco), MaSp1nuc and MaSp1pla, respectively. The partial sequence of MaSp1 encodes six repetitive glycine-rich and polyalanine tandem domains, and we evaluated the effect of its expression on plant mechanical properties and physiology. While MaSp1 expression showed no effect on leaf mechanical properties, it conferred drought tolerance. MaSp1-tobacco demonstrated an increased growth on PEG-infused growth medium and higher drought recovery in soil compared to the non-transgenic control (WT). Transcriptome analyses of drought-stressed MaSp1-tobacco revealed an upregulation of genes involved in stress response, antioxidant activity, and phenylpropanoid biosynthesis, with a higher effect of drought on the MaSp1pla transcriptome. Genes encoding peroxidase, stress and channel proteins, and cellular metabolism and homeostasis were consistently upregulated in these lines, which also displayed a higher total antioxidant status (TAS) compared to WT, and a higher TAS in MaSp1pla compared to MaSp1nuc. Under normal watering conditions, the ABA content and the TAS in MaSp1-tobacco were significantly higher than in the WT. Our results show that nucleus- and plastid-encoded expression of MaSp1 in tobacco increased the endogenous ABA levels, which led to the formation of plant stress memory that caused overall adjustments in multiple drought tolerance mechanisms and hence, conferred drought tolerance.
Project description:The conservation of the endangered Korean fir, Abies koreana, is of critical ecological importance. In our previous study, a yeast-like fungus identified as Aureobasidium pullulans AK10, was isolated and shown to enhance drought tolerance in A. koreana seedlings. In this study, the effectiveness of A. pullulans AK10 treatment in enhancing drought tolerance in A. koreana was confirmed. Furthermore, using transcriptome analysis, we compared A. koreana seedlings treated with A. pullulans AK10 to untreated controls under drought conditions to elucidate the molecular responses involved in increased drought tolerance.
Project description:Drought priming is a promising approach to improve drought tolerance, and root apex plays important role in coping with drought adversities in plants. It has been observed that less inhibition of root growth under drought stress was found in paralleling with the enhanced drought tolerance induced by drought priming in wheat. However, the contribution and mechanisms of root apex to the improved tolerance induced by drought priming remains unknown. Here, the transcriptome and proteome of three different zones along the root axis under drought stress were investigated. The two zones distal from the root apex showed more sensitive to drought priming and the later drought stress than the zone proximal to the root apex, as exemplified by the principal component analysis of the different expressed genes (DEGs) among treatments. The DEGs which decreased by drought stress, while higher expressed in primed plants than non-primed plants, might play critical roles in enhanced root growth in primed plants. These genes were mainly involved in the pathways related to cell membrane sensing, plant hormone signaling, stress defense and cell more modification. Moreover, the plant hormone pathway showed positive correlated between transcriptome and proteome analysis, and genes network analysis hinted that ABA receptor and aquaporin could be potential markers in regulation of priming induced root growth and drought stress tolerance.
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