Role of ABA in Arabidopsis Salt, Drought, and Desiccation Tolerance

Abstract

The ability of plants to respond to environmental stimuli is essential to plant survival. Abscisic acid ABA is a phytohormone with roles at various stages of plant development. ABA also plays a major role in mediating physiological responses to environmental stresses such as salt, osmotic, and cold stress. Plant responses to environmental stress have been widely studied in the model plant Arabidopsis thaliana and ABA signaling mechanisms elucidated. In general, the adaptive responses of plants to various stress conditions can be either ABA-dependent or ABA-independent. Here we focus on the role of ABA in stress signaling and abiotic stress tolerance. We describe the intrinsic mechanisms that confer stress tolerance via ABA, as well as how ABA-regulated gene products play a role in salt and drought tolerance at different stages of the life cycle. In addition, the contribution of ABA to regulation of stomatal aperture and therefore desiccation tolerance will be discussed. Understanding ABA signaling mechanisms in abiotic stress provides avenues for improving plant performance.

Antisense transcription represses Arabidopsis seed dormancy QTL DOG 1 to regulate drought tolerance

“…Treatment with ABA resulted in nearly complete silencing of the antisense promoter activity in leaves, compared to mock‐ or GA‐treated plants (Figs A and B, and EV2A and B, Appendix Fig S1). ABA plays an important role in the response of plants to stress, including water deprivation where it acts as part of a signalling cascade leading to drought resistance . Subsequently, we showed that the DOG1 antisense promoter was also strongly downregulated in response to 5 days of water withdrawal (Figs C and D, and EV3A–C), a result validated by strand‐specific RT–qPCR analysis in Col‐0 (WT) plants (Fig E).…”

Transcriptomic reprogramming in soybean seedlings under salt stress

“…Although closing the stomata could be an immediate adaptive response for protection against salt shock by reducing water loss, soybean seedlings also need to at least partially resume transpiration and photosynthesis by reopening them. ABA is a major regulator of stomatal closure, and the ABA signaling pathway is well known to be associated with responses to environmental stresses (Fernando & Schroeder, ). Here, we observed the induction of genes for ABA biosynthesis and ABF, a major downstream TF, as well as other ABA response genes such as RD29B and RD22 (Table ).…”

“…Multiple signal transduction pathways are activated to cope with salt stress, such as the phytohormone‐mediated, Ca 2+ ‐dependent, and phosphatidylinositol signals (Fernando & Schroeder, ; Ji et al, ; Xue, Chen, & Mei, ). These signaling pathways activate other regulators, such as transcription factors (TFs) to amplify the signals for gene regulation, and finally initiate protective mechanisms through the induction or repression of functional genes (Lata, Yadav, & Prasad, ).…”

Arabidopsis thaliana Raf22 protein kinase maintains growth capacity during postgerminative growth arrest under stress

“…High salinity and high osmolality induce an increase of endogenous ABA levels (Fernando & Schroeder, ) and PGG arrest. We examined whether AtRaf22 modulates the arrest of PGG induced by high salinity or osmolality.…”