Project description:Five allotetraploid cotton species have adapted, through their transcriptional responses, to unique environments with distinct levels of inherent abiotic stresses. The transcriptional responses of leaf and root tissue in five allotetraploid cotton species (Gossypium hirsutum, G. barbadense, G. tomentosum, G. mustelinum, and G. darwinii) under salt stress have been investigated in this study using cotton long oligonucleotide microarrays. Physiological responses to salinity such as stomatal conductance, ion and osmoprotectant contents were also measured as indicators of imposed stress. Accessions from these five cotton species were hydroponically grown and gradually introduced to a NaCl treatment (15 dS m-1). The microarray results identified 2721 and 2460 differentially expressed genes under salt stress that were significant in leaf and root tissue, respectively. Many of these genes were classified under gene ontology (GO) categories that suggest abiotic stress. These allotetraploid cottons shared transcriptional responses to salinity, but also showed responses that were species-specific. No consistent differences in transcriptional response among the previously estimated phylogenetic branches were found. Stomatal conductance, ion accumulation, and betaine, trigonelline, and trehalose contents also indicated salt stress. This global assessment of transcriptional and physiological responses to salt stress of these cotton species may identify possible gene targets for crop improvement and evolutionary studies of cotton. Keywords: CEGC Cotton oligo salt stress
Project description:Five allotetraploid cotton species have adapted, through their transcriptional responses, to unique environments with distinct levels of inherent abiotic stresses. The transcriptional responses of leaf and root tissue in five allotetraploid cotton species (Gossypium hirsutum, G. barbadense, G. tomentosum, G. mustelinum, and G. darwinii) under salt stress have been investigated in this study using cotton long oligonucleotide microarrays. Physiological responses to salinity such as stomatal conductance, ion and osmoprotectant contents were also measured as indicators of imposed stress. Accessions from these five cotton species were hydroponically grown and gradually introduced to a NaCl treatment (15 dS m-1). The microarray results identified 2721 and 2460 differentially expressed genes under salt stress that were significant in leaf and root tissue, respectively. Many of these genes were classified under gene ontology (GO) categories that suggest abiotic stress. These allotetraploid cottons shared transcriptional responses to salinity, but also showed responses that were species-specific. No consistent differences in transcriptional response among the previously estimated phylogenetic branches were found. Stomatal conductance, ion accumulation, and betaine, trigonelline, and trehalose contents also indicated salt stress. This global assessment of transcriptional and physiological responses to salt stress of these cotton species may identify possible gene targets for crop improvement and evolutionary studies of cotton. Keywords: CEGC Cotton oligo salt stress The transcriptional responses of leaf and root tissue in five allotetraploid cotton species (Gossypium hirsutum, G. barbadense, G. tomentosum, G. mustelinum, and G. darwinii) under salt stress have been investigated in this study using cotton long oligonucleotide microarrays. Physiological responses to salinity such as stomatal conductance, ion and osmoprotectant contents were also measured as indicators of imposed stress. Accessions from these five cotton species were hydroponically grown and gradually introduced to a NaCl treatment (15 dS m-1).
Project description:Purpose:Identification of genes and miRNAs responsible for salt tolerance in upland cotton (Gossypium hirsutum L.) would help reveal the molecular mechanisms of salt tolerance. We performed physiological experiments and transcriptome sequencing (mRNA-seq and small RNA-seq) of cotton leaves under salt stress using Illumina sequencing technology. And quantitative reverse transcription polymerase chain reaction (qRT–PCR) methods and to evaluate protocols for optimal high-throughput data analysis Methods:We investigated two distinct salt stress phases—dehydration (4 h) and ionic stress (osmotic restoration; 24 h)—that were identified by physiological changes of 14-day-old seedlings of two cotton genotypes, one salt tolerant and the other salt sensitive, during a 72-h NaCl exposure. A comparative transcriptomics approach was used to monitor gene and miRNA differential expression at two time points (4 and 24 h) in leaves of the two cotton genotypes under salinity conditions. Results:During a 24-h salt exposure, 819 transcription factor unigenes were differentially expressed in both genotypes, with 129 unigenes specifically expressed in the salt-tolerant genotype. Under salt stress, 108 conserved miRNAs from known families were differentially expressed at two time points in the salt-tolerant genotype. Conclusions:Our comprehensive transcriptome analysis has provided new insights into salt-stress response of upland cotton. The results should contribute to the development of genetically modified cotton with salt tolerance.
Project description:To detect salt-tolerance-related miRNAs, comparative analysis of miRNA expression profiles was performed between the salt-tolerant and -sensitive cotton cultivars in control and salt-stressed conditions (treated with 300 mM NaCl for 24 h) using microRNA microarray Total RNA was extracted from (1) the seedling of salt-tolerant cotton cultivar in normal growth conditions, (2) the seedling of salt-tolerant cotton cultivar in salt-stressed growth conditions, (3) the seedling of salt-sensitive cotton cultivar in normal growth conditions, and (4) the seedling of salt-sensitive cotton cultivar in salt-stressed growth conditions. Then, the low-molecular-weight RNA (LMW-RNA) was isolated using the PEG solution precipitation method and used to hybridization.
Project description:To detect salt-tolerance-related miRNAs, comparative analysis of miRNA expression profiles was performed between the salt-tolerant and -sensitive cotton cultivars in control and salt-stressed conditions (treated with 300 mM NaCl for 24 h) using microRNA microarray
Project description:Cotton is an excellent model for studying heterosis, crop domestication and bioengineering improvement. Chromatin profiling helps to reveal how histone modifications are involved in controlling differential gene expression between A and D subgenome in allotetraploid cotton. However, the detailed profiling and functional characterization of H3K27me3 and H3K4me3/H3K27me3 bivalent mark are still understudied in cotton. In this study, we conducted H3K4me3 and H3K27me3-related ChIP-seq followed by comprehensively characterizing their roles in regulating gene transcription in cotton. We found that H3K4me3 and H3K27me3 exhibited active and repressive roles in regulating expression of genes between A and D subgenome, respectively. Expression of H3K4me3-H3K27me3 bivalent genes was regulated by combinatorial actions of both marks and may be dominantly controlled by H3K4me3. More importantly, H3K4me3 exhibited enrichment levels, positioning and distance-related effects on expression levels of related genes. In addition, H3K4me3, H3K27me3 and bivalent mark can indirectly influence gene expression through TF-mediated regulatory networks. Thus, our study provides insights in functions of H3K4me3 and H3K27me3 in regulating differential gene expression between A and D subgenome in cotton.
Project description:Cotton is an excellent model for studying heterosis, crop domestication and bioengineering improvement. Chromatin profiling helps to reveal how histone modifications are involved in controlling differential gene expression between A and D subgenome in allotetraploid cotton. However, the detailed profiling and functional characterization of H3K27me3 and H3K4me3/H3K27me3 bivalent mark are still understudied in cotton. In this study, we conducted H3K4me3 and H3K27me3-related ChIP-seq followed by comprehensively characterizing their roles in regulating gene transcription in cotton. We found that H3K4me3 and H3K27me3 exhibited active and repressive roles in regulating expression of genes between A and D subgenome, respectively. Expression of H3K4me3-H3K27me3 bivalent genes was regulated by combinatorial actions of both marks and may be dominantly controlled by H3K4me3. More importantly, H3K4me3 exhibited enrichment levels, positioning and distance-related effects on expression levels of related genes. In addition, H3K4me3, H3K27me3 and bivalent mark can indirectly influence gene expression through TF-mediated regulatory networks. Thus, our study provides insights in functions of H3K4me3 and H3K27me3 in regulating differential gene expression between A and D subgenome in cotton.
Project description:Plants respond to stress by using multiple gene regulatory mechanisms including the post-transcriptional regulation of gene expression. The stresses suffered by plants under salinity include osmotic stress and ion stress. In this study, three cotton small RNA libraries were constructed and sequenced under normal consideration, osmotic and ionic stress. The length distribution of obtained small RNAs was significantly different between libraries. A total of 228 cotton miRNAs were identified. Of them 24 were novel miRNAs. There were 88 and 75 miRNAs with different expression in response to the influence of osmotic and ionic factors of saline stress, respectively. The identification of these small RNAs as well as elucidating their functional significance broadens our understanding of the post-transcriptional gene regulations in response to salt stress.
Project description:rs06-07_della - della-regulation of salt stress responses - Identification of DELLA-dependent dowtream targets in response to salt stress - Aim was to determine downstream target of DELLA proteins involved in salt stress tolerance. Wt, ga1-3, penta seeds were sterilized, sown on MS agar plates then put for stratification for 3 days at 4degreeC. Plates were placed in growth cabinet for 9 days. Seedlings were transferred to 24 well-plates, with 2 seedlings per well (0.5 ml MS liquid per well). Plates were placed in the same condition for 3 days. Finally, NaCl were added (final concentration 200 mM), except for the control. The salt treatment was applied for 30 min and 1h. Treatment was stopped by freezing in liquid nitrogen. Keywords: dose response,gene knock out,time course
Project description:rs06-07_della - della-regulation of salt stress responses - Identification of DELLA-dependent dowtream targets in response to salt stress - Aim was to determine downstream target of DELLA proteins involved in salt stress tolerance. Wt, ga1-3, penta seeds were sterilized, sown on MS agar plates then put for stratification for 3 days at 4degreeC. Plates were placed in growth cabinet for 9 days. Seedlings were transferred to 24 well-plates, with 2 seedlings per well (0.5 ml MS liquid per well). Plates were placed in the same condition for 3 days. Finally, NaCl were added (final concentration 200 mM), except for the control. The salt treatment was applied for 30 min and 1h. Treatment was stopped by freezing in liquid nitrogen. Keywords: dose response,gene knock out,time course 12 dye-swap - CATMA arrays