632 / 2019-04-27 17:08:00

Identification of protein factors that regulate ABA-unresponsive subclass I SnRK2s in Arabidopsis

osmotic stress,high salt stress,drought stress,dehydration stress,SnRK2

全体主题 > Abiotic Stress

Plants sense and adapt to osmotic stresses, such as drought and high salinity, and control growth and development under the conditions. SNF1-related protein kinase 2 (SnRK2s) play important roles in abscisic acid (ABA) and osmotic stress signaling in plants. Although it was well known that subclass III-type SnRK2s is main regulators of ABA signaling and positively regulate osmotic stress tolerances, the functions of ABA-unresponsive subclass I-type SnRK2s were mostly unknown. We previously reported that subclass I SnRK2s phosphorylated a mRNA decapping activator VARICOSE (VCS) to regulate mRNA decay and plant growth under osmotic stress. Furthermore, we are analyzing the activation mechanisms of subclass I SnRK2s under osmotic stress in an ABA-independent pathway. In this study, to reveal novel upstream factors of subclass I SnRK2s, we performed Co-IP and LC-MS/MS analysis and identified subclass I SnRK2-interacting proteins. We found that subclass I SnRK2s interacted with OSRK protein kinases (Osmotic stress responsive kinase) in P-bodies under osmotic stress. Notably, subclass I SnRK2 could not be activated in a mutant lacking OSRKs under osmotic stress conditions. Transcriptome analysis revealed that downstream genes of OSRKs largely overlapped with subclass I SnRK2-regulated genes under osmotic stress. Our data suggested that OSRK protein kinases regulate the subclass I SnRK2-VCS pathway under osmotic stress.