The Role of ABA-Responsive Transcription Factors In the Regulation of Cotton Drought Stress Tolerance

Drought adversely impacts plant growth and reduces productivity; as aquifers are depleted, and rainfall distributions shift, the development of crops that can thrive with less water is necessary to maintain, and increase, viability and yield. ABA-responsive element binding factors (ABFs) and their respective pathway and targets, act in response to abiotic stresses, particularly drought, to reduce water loss and increase tolerance to water deficit as indicated by previous work through the constitutive expression of ABF3 from Arabidopsis (AtABF3) in cotton. However, this heterologous expression also had significant negative effects, such as delayed development and reduced productivity.

The goal of this work is to characterize the ABFs and regulators of the ABA-responsive pathway in cotton, and develop plants that are able to tolerate drought conditions. We hypothesize that, in contrast to heterologous expression of AtABF3, endogenous cotton ABF overexpression will lead to increased drought tolerance without the aforementioned negative consequences. Though in the preliminary stages, we will overexpress select endogenous ABFs in cotton, and evaluate the response to water deficit and the effect on agronomic characteristics, to determine the viability of ABF transgenics for commercialization of drought stress tolerance in cotton.