CML20, an Arabidopsis Calmodulin-like Protein, Negatively Regulates Guard Cell ABA Signaling and Drought Stress Tolerance.

ABSTRACT: Guard cells shrink in response to drought and abscisic acid (ABA), which is caused by efflux of ions that in turn reduces stomatal aperture and improves the plant's ability to retain moisture. Cytosolic free calcium is an essential secondary messenger in guard cell ABA signaling, but the details of this regulatory pathway remain sketchy. Here, the calmodulin-like protein CML20, which has four EF-hand domains and calcium-binding activity in vitro, was found to be a negative regulator of ABA-induced stomatal movement in Arabidopsis. The guard cells of cml20 loss-of-function mutant plants were hypersensitive to both ABA-activated S-type anion currents, and ABA inhibited inward K⁺ currents than those of wild type. Additional, due to smaller stomatal aperture,

SUBMITTER: Wu X 

PROVIDER: S-EPMC5445667 | biostudies-literature | 2017

REPOSITORIES: biostudies-literature