The Role of Abscisic Acid in Drought Stress: How ABA Helps Plants to Cope with Drought Stress
The exploration of plant response to drought stress is a key to understanding the mechanisms of the drought signaling network and further implementing the knowledge in breeding programs of crops. Plant hormones are crucial factors in transducing the stress signal and the main player among them is abscisic acid (ABA) ABA controls plants' stress response at many layers of regulation. These include (1) transcriptional response including interactions of core transcription factors that are regulated by ABA and other plant hormones, and (2) regulation of ABA metabolism and transport itself, with posttranscriptional and posttranslational regulation which still seems to be a hidden and not fully recognized part of stress signaling. The efficient integration and coordination of ABA metabolism, transport, and regulation of core signaling elements are pivotal for maintaining tissue and cell type specific hormone concentration and thus signaling efficiency, to achieve the proper growth and developmental responses. Among lifecycle processes controlled by ABA are: inhibition of germination, restriction of shoot and root growth, and stomatal closure. Here, we describe recent advances in decoding the ABA signaling message transmitted through plant cells under drought stress that builds drought tolerance.