MPK9 and MPK12 function in SA-induced stomatal closure in Arabidopsis thaliana |
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Authors: | Md. Atiqur Rahman Khokon Mohammad Abdus Salam Fabien Jammes Wenxiu Ye Mohammad Anowar Hossain Eiji Okuma |
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Affiliation: | 1. Graduate School of Environmental and Life Science, Okayama University, Okayama, Japan;2. Department of Biology, Pomona College, Claremont, CA, USA |
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Abstract: | Salicylic acid (SA) induces stomatal closure sharing several components with abscisic acid (ABA) and methyl jasmonate (MeJA) signaling. We have previously shown that two guard cell-preferential mitogen-activated protein kinases (MAPKs), MPK9 and MPK12, positively regulate ABA signaling and MeJA signaling in Arabidopsis thaliana. In this study, we examined whether these two MAPKs are involved in SA-induced stomatal closure using genetic mutants and a pharmacological, MAPKK inhibitor. Salicylic acid induced stomatal closure in mpk9 and mpk12 single mutants but not in mpk9 mpk12 double mutants. The MAPKK inhibitor PD98059 inhibited SA-induced stomatal closure in wild-type plants. Salicylic acid induced extracellular reactive oxygen species (ROS) production, intracellular ROS accumulation, and cytosolic alkalization in the mpk9, mpk12, and mpk9 mpk12 mutants. Moreover, SA-activated S-type anion channels in guard cells of wild-type plants but not in guard cells of mpk9 mpk12 double mutants. These results imply that MPK9 and MPK12 are positive regulators of SA signaling in Arabidopsis guard cells. |
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Keywords: | cytosolic alkalization mitogen-activated protein kinase reactive oxygen species salicylic acid S-type anion channel in guard cells |
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