Project description:Genome-wide profiling of miRNAs and their target genes during somatic embryogenesis in cotton by small RNA and degradome sequencing
Project description:Cotton (Gossypium hirsutum) is widely distributed worldwide, and improving the quality of its fiber is one of the most important tasks in cotton breeding. Cotton fibers are primarily composed of cellulose, which is synthesized and regulated by cellulose synthase (CesAs). However, the molecular mechanism of CesA genes in cotton is unclear. In this study, the cotton transcriptome and metabolome were used to investigate the significant function of CesA genes in fiber development. Finally, 321 metabolites were obtained, 84 of which were associated with the corresponding genes. Interestingly, a target gene named Gh_A08G144300, one of the CesA gene family members, was closely correlated with the development of cotton fibers. Then, identification and functional analysis were conducted. The target CesA gene Gh_A08G144300 was selected and analysed to determine its specific function in cotton fiber development. High-level gene expression of Gh_A08G144300 was found at different fiber development stages by RNA-seq analysis, and the silencing of Gh_A08G144300 visibly inhibited the growth of cotton fibers, showing that it is critical for their growth. This study provides an important reference for research on the gene function of Gh_A08G144300 and the regulatory mechanism of fiber development in cotton.
Project description:This study was initiated with the objective of identifying the anther/tapetum specific promoters from cotton floral buds. Cotton is an important commercial crop. Hybrid cotton varieties are developed to obtain improved yield and fiber quality. Most of the hybrid seed production in cotton is carried out by hand emasculation, which requires large amount of manpower, resulting in high cost of hybrid seed. We are developing barnase-barstar based male sterility system, which would be a better alternative for hybrid development. The tapetum specific promoters are main requirement for such a system. The study was thus carried out to identify genes expressed in the anthers.
Project description:Identification of candidate thermotolerance genes during early seedling stage in upland cotton (Gossypium hirsutum L.) revealed by comparative transcriptome analysis
Project description:High temperature (HT) stress is a major environmental stress that limits cotton growth, metabolism, and yield worldwide. The identification and characterization of thermotolerance is restricted by the plant growth environment and growth stage. In this study, four genotypes of upland cotton (Gossypium hirsutum L.) with known field thermotolerance were evaluated under normal and HTs at the seedlings stage in a growth cabinet with 11 physiological, biochemical, and phenotypic assays. Consistent with previous field observations, the thermotolerance could be identified by genotype differences at the seedling stage under HT in a growth cabinet. Comparative transcriptome analysis was performed on seedlings of two contrasting cotton genotypes after 4 and 8 hours of HT exposure. Gene ontology analysis combined with BLAST annotations revealed a large number of HT-induced differentially expressed genes (4,698) that either exhibited higher expression levels in the heat-tolerant genotype (Nan Dan Ba Di Da Hua) compared with the heat-sensitive genotype (Earlistaple 7), or were differentially expressed only in Nan Dan Ba Di Da Hua. These genes encoded mainly protein kinases, transcription factors, and heat shock proteins, which were considered to play key roles in thermotolerance in upland cotton. Two heat shock transcription factor genes (homologs of AtHsfA3, AtHsfC1) and AP2/EREBP family genes (homologs of AtERF20, AtERF026, AtERF053, and AtERF113) were identified as possible key regulators of thermotolerance in cotton. Some of the differentially expressed genes were validated by quantitative real-time PCR analysis. Our findings provide candidate genes that could be used to improve thermotolerance in cotton cultivars.
Project description:Background: Dwarf cottons are more resistant to damage from wind and rain and associated with stable, increased yields, and also desirable source for breeding the machine harvest varieties. In an effort to uncover the transcripts and miRNA networks involved in plant height, the transcriptome and small RNA sequencing were performed based on dwarf mutant Ari1327 (A1), tall-culm mutant Ari3697 (A3) and wild type Ari971 (A9) in Gossypium hirsutum. Results: The transcriptome sequencing analysis showed that the enriched pathways of top 3 differentially expressed genes (DEGs) were categorized as carotenoid biosynthesis, plant-pathogen interaction and plant hormone signal transduction in both A1-A9 and A3-A9. The ABA and IAA related factors were differentially expressed in the mutants. Importantly, we found the lower expressed SAUR and elevated expressed GH3, and ABA related genes such as NCED and PP2C maybe relate to reduced growth of the plant height in Ari1327 which is consistent with the higher auxin and ABA content in this mutant. Furthermore, miRNA160 targeted to the auxin response factor (ARF) and miRNA166 (gma-miR166u and gma-miR166h-3p) targeted to ABA responsive element binding factor were related to the mutation in cotton. We have noticed that the cell growth related factors (smg7 targeted by gra-miR482 and 6 novel miRNAs and Pectatelyases targeted by osa-miR159f), the redox reactions related factors (Cytochrome P450 targeted by miR172) and MYB genes targeted by miR828, miR858 and miR159 were also involved in plant height of the cotton mutants. A total of 226 conserved miRNAs representing 32 known miRNA families were obtained, and 38 novel miRNAs corresponding to 23 unique RNA sequences were identified. Total 531 targets for 211 conserved miRNAs were obtained. Using PAREsnip, 27 and 29 miRNA/target conserved interactions were validated in A1-A9 and A3-A9, respectively. Furthermore, miRNA160, miRNA858 and miRNA172 were validated to be up-regulated in A1-A9 but down-regulated in A3-A9, whereas miRNA159 showed the opposite regulation. Conclusions: This comprehensive interaction of the transcriptome and miRNA at tall-culmand dwarf mutant led to the discovery of regulatory mechanisms in plant height. It also provides the basis for in depth analyses of dwarf mutant genes for further breeding of dwarf cotton.