Working group session:
Functional Genomics
Presentation type:
oral
Authors:
Allen, Randy
Presenter:
Allen, Randy
Correspondent:
Allen, Randy
Abstract:
Abiotic stress associated with insufficient water is a primary limiting factor for most crop plants, including cotton. Plants are able to acclimate to reduced water availability through physiological and biochemical responses to reduce water loss, protect tissues from damage, and repair tissue damage once it has occurred. Acclimation is dependent on changes in gene expression that are controlled by a wide range of regulatory mechanisms functioning at all levels of the gene expression system from chromatin-based epigenetic signaling through ubiquitin-dependent protein lability. Using information from model systems such as Arabidopsis, we are evaluating the functions of a number of stress-responsive regulatory factors in cotton. These include well characterized transcription factors such as ABF and CBF proteins, along with more recently identified factors involved in chromatin remodeling and ubiquitin ligases that regulate the activity and stability of other regulatory proteins. Our results indicate that individual regulatory factors can affect stress responses in specific ways. For example, expression of the ABA-responsive transcription factor ABF3 strongly impacts stomatal responses while expression of the ABA-dependent transcription factor CBF3 does not. These functional differences suggest the possibility of synergistic action. Also, since inappropriate expression of some regulatory factors can negatively affect plant development and productivity, effective use of these genes requires optimization of transgene structure using a variety of transcriptional promoters to optimize expression patterns. Based on these and other results, we anticipate that this research will provide a deeper understanding of the genetic factors that determine stress tolerance traits in cotton and facilitate the translation of basic research findings into applications that can benefit producers throughout the world.