HOS15: A missing link that fine-tunes ABA signaling and drought tolerance in Arabidopsis.

Akhtar Ali, Dae-Jin Yun

Plant signaling & behavior 2020 Jul 02

filter terms:

Among the phytohormones, abscisic acid (ABA) specifically regulates plant adaptation to osmotic stresses, such as drought and high salinity, by controlling the internal water status in plants. A signiﬁcant accumulation of ABA occurs in response to conditions of water deﬁcit; this is followed by a sophisticated signaling relay, known as the ABA signaling pathway, which decreases the rate of transpiration through stomatal closure, thereby suppressing photosynthetic activity. Snf1-related kinases (SnRK2s) are the major components regulating the ABA signaling pathway. Of these, SnRK2.6 (OST1) and SnRK2.3 are negatively regulated by HOS15 (HIGH EXPRESSION OF OSMOTICALLY RESPONSIVE15), in an ABA-dependent manner, to cease the signaling relay. HOS15 is a WD40-repeat protein that regulates several physiological processes, including plant growth and development, freezing stress responses, and ABA signaling. Here, we provide a brief overview of the functional importance of HOS15 in the regulation of ABA signaling and drought stress.

Citation

Akhtar Ali, Dae-Jin Yun. HOS15: A missing link that fine-tunes ABA signaling and drought tolerance in Arabidopsis. Plant signaling & behavior. 2020 Jul 02;15(7):1770964