3 research outputs found
Natural Variation in Arabidopsis Cvi-0 Accession Reveals an Important Role of MPK12 in Guard Cell CO2 Signaling
Plant gas exchange is regulated by guard cells that form stomatal pores.
Stomatal adjustments are crucial for plant survival; they regulate
uptake of CO2 for photosynthesis, loss of water, and entrance of air
pollutants such as ozone. We mapped ozone hypersensitivity, more open
stomata, and stomatal CO2-insensitivity phenotypes of the Arabidopsis
thaliana accession Cvi-0 to a single amino acid substitution in
MITOGEN-ACTIVATED PROTEIN (MAP) KINASE 12 (MPK12). In parallel, we
showed that stomatal CO2-insensitivity phenotypes of a mutant cis
(CO2-insensitive) were caused by a deletion of MPK12. Lack of MPK12
impaired bicarbonate-induced activation of S-type anion channels. We
demonstrated that MPK12 interacted with the protein kinase HIGH LEAF
TEMPERATURE 1 (HT1)-a central node in guard cell CO2 signaling-and that
MPK12 functions as an inhibitor of HT1. These data provide a new
function for plant MPKs as protein kinase inhibitors and suggest a
mechanism through which guard cell CO2 signaling controls plant water
management.</p