1a. Objectives (from AD-416):
Generate a whole cotton transcriptome profile of water deficit stress responsive genes and determine the expression patterns of aquaporin genes across genotypes.
1b. Approach (from AD-416):
This project consists of two parts. First, we will use next generation sequencing technology to generate a comprehensive whole transcriptome profile of cotton genes differentially expressed in response to water deficit stress. Leaf and root transcriptomes from a single genotype will be compared between well-watered and water-deficit stressed field treatments. Second, we will use quantitative polymerase chain reaction (PCR) to functionally characterize aquaporin gene expression during cotton growth and development. Tissue and developmental specific gene expression patterns of individual aquaporin genes across different genotypes will be quantitatively measured in response to specific environmental conditions.
3. Progress Report:
This project is related to objective 1 of the in-house project: to develop genetic resources and cropping practices that increase cotton water-use efficiency. Water deficit stress is known to be a major inhibitor of environmentally and economically sustainable cotton production systems. The primary objective of this cooperative research project is to identify genes with expression sensitivity to water deficit stress. A single cultivar, reported to be tolerant to water deficit stress, was grown in the field under well watered and water limited conditions. High-throughput, next-generation genetic sequencing techniques were used to assay the expression of 34,000 cotton genes. We compared gene expression differences independently in leaf and root tissues between well-watered and water deficit stress treatments. We also compared gene expression differences between leaf and root tissue and between water treatments. For all differentially expressed genes, we are annotating their biological function and narrowing to a manageable number for future studies. In total, the database of genes differentially expressed (in root, leaf, or root and leaf) in response to water deficit stress provides candidate genetic targets for improving cotton’s productivity under water deficit stress. Geneticists and breeders can use this information to mine the extensive cotton genetic resources for novel versions of candidate genes that can be deployed in contemporary cotton breeding programs.