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bioRxiv · 10.1101/723627

ABA-dependent and ABA-independent functions of RCAR5/PYL11 in response to cold stress

Lim, C. W.·Lee, S. C.
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Abstract

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.

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Lim, C. W., Lee, S. C.. 2019-08-02. ABA-dependent and ABA-independent functions of RCAR5/PYL11 in response to cold stress. https://doi.org/10.1101/723627

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