Evaluation of mRNA stability regulation of components of the Abscisic Acid (ABA) core signaling pathway

Abstract

The Abscisic Acid (ABA) modulates gene expression not only through transcriptional control, but also by controlling the stability of several transcripts. For instance, in Arabidopsis thaliana, the expression control of the transcription factor AtbZIP63, which integrates responses between energetic and abiotic stresses, involves transcriptional and post-transcriptional mechanisms in response to ABA and glucose. Our research group identified 245 transcripts in A. thaliana whose stability that are potentially regulated by ABA, among which are highlighted several transcripts that encode for proteins that are part of the ABA core signaling pathway. However, the underlying mechanisms related to the modulation of the stability of these transcripts in response to ABA are still unknown. Preliminary gene expression results obtained by response kinetic assays to ABA indicate a trend to the shutdown/attenuation of the hormone's core signaling pathway. This negative feedback regulation possibly reflects aspects of the homeostasis control in response to ABA signaling. Thus, the mRNA stability control may contribute as fast-responsive component for fine-tuning the ABA-promoted responses, possibly integrating the negative feedback regulation process. In this research project, we propose to unravel some of the mechanisms by which ABA controls the stability of transcripts of its core signaling pathway, as well as to understand the physiological meaning of these regulations. (AU)