FRET kinase sensor development reveals SnRK2/OST1 activation by ABA but not by MeJA and high CO₂ during stomatal closure.

ABSTRACT: Sucrose-non-fermenting-1-related protein kinase-2s (SnRK2s) are critical for plant abiotic stress responses, including abscisic acid (ABA) signaling. Here, we develop a genetically encoded reporter for SnRK2 kinase activity. This sensor, named SNACS, shows an increase in the ratio of yellow to cyan fluorescence emission by OST1/SnRK2.6-mediated phosphorylation of a defined serine residue in SNACS. ABA rapidly increases FRET efficiency in N. benthamiana leaf cells and Arabidopsis guard cells. Interestingly, protein kinase inhibition decreases FRET efficiency in guard cells, providing direct experimental evidence that basal SnRK2 activity prevails in guard cells. Moreover, in contrast to ABA, the stomatal closing stimuli, elevated CO₂ and MeJA, did not increase SNACS

SUBMITTER: Zhang L 

PROVIDER: S-EPMC7289597 | biostudies-literature | 2020 May

REPOSITORIES: biostudies-literature