PT  - JOURNAL ARTICLE
AU  - Chae Woo Lim
AU  - Sung Chul Lee
TI  - ABA-dependent and ABA-independent functions of RCAR5/PYL11 in response to cold stress
AID  - 10.1101/723627
DP  - 2019 Jan 01
TA  - bioRxiv
PG  - 723627
4099  - http://biorxiv.org/content/early/2019/08/02/723627.short
4100  - http://biorxiv.org/content/early/2019/08/02/723627.full
AB  - Arabidopsis thaliana has 14 abscisic acid (ABA) receptors—PYR1/PYLs/RCARs—which have diverse and redundant functions in ABA signaling; however, the precise role of these ABA receptors remains to be elucidated. Here, we report the functional characterization of RCAR5/PYL11 in response to cold stress. Expression of RCAR5 gene in dry seeds and leaves was ABA-dependent and ABA-independent, respectively. Under cold stress conditions, seed germination was markedly delayed in RCAR5-overexpressing (Pro35S:RCAR5) plants, but not in Pro35S:RCAR5 in ABA-deficient (aba1-6) mutant background. Leaves of Pro35S:RCAR5 plants showed enhanced stomatal closure—independent of ABA—and high expression levels of cold, dehydration, and/or ABA-responsive genes; these traits conferred enhanced freezing tolerance. Our data suggest that RCAR5 functions in response to cold stress by delaying seed germination and inducing rapid stomatal closure via ABA-dependent and ABA-independent pathways, respectively.