Two Arabidopsis guard cell-preferential MAPK genes,MPK9 and MPK12, function in biotic stress response |
| |
| Authors: | Fabien Jammes Xiaohua Yang Shunyuan Xiao June M Kwak |
| |
| Institution: | (1) University of Maryland; College Park, MD, USA;(2) Department of Cell Biology and Molecular Genetics;(3) University of Maryland; College Park, MD, USA; Institute for Bioscience and Biotechnology Research;(4) University of Maryland; College Park, MD, USA; Institute for Bioscience and Biotechnology Research; Department of Plant Molecular Systems Biotechnology and Crop Biotech Institute; Kyung Hee University; Yongin, Korea |
| |
| Abstract: | Abscisic acid (ABA) plays a major role in plant development and adaptation to severe environmental conditions. ABA evokes cellular events to regulate stomatal apertures and thus contributes to the plant’s ability to respond to abiotic stresses. Reactive oxygen species (ROS) are produced in response to ABA and mediate ABA-induced stomatal closure. We have shown that two MAP kinases, MPK9 and MPK12, are highly and preferentially expressed in guard cells and function as positive regulators of ROS-mediated ABA signaling in guard cells. Cell biological and electrophysiological analyses demonstrated that MPK9 and MPK12 act downstream of ROS and cytosolic Ca2+ and upstream of anion channels in the guard cell ABA signaling cascade. Plant pathogens use stomata as the primary gateway to enter into their hosts, and previous studies have indicated crosstalk between ABA and defense signaling. Here we show that mpk9-1/12-1 double mutants are highly susceptible to Pseudomonas syringae DC3000 compared to WT plants. These results suggest that the regulation of stomatal apertures by MPK9 and MPK12 contributes to the first line of defense against pathogens. |
| |
| Keywords: | abscisic acid biotic stress crosstalk defense guard cell MAP kinase |
|
|
