MPK9 and MPK12 regulate YEL signalling in stomata

 

 

Two guard cell-preferential MAPKs, MPK9 and MPK12, regulate YEL signalling in Arabidopsis guard cells

by Salam M. A., Jammes F., Hossain M. A., Ye W., Nakamura Y., Mori I. C., Kwak J. M., Murata Y. (2013)

Mohammad Abdus Salam, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Kālīganj, Bangladesh

Fabien Jammes, University of Maryland, College Park, USA

Mohammad Anowar Hossain, Bangladesh Agricultural University, Mymensingh, Bangladesh

Wenxiu Ye, Nagoya University, Japan

Yoshimasa Nakamura, Okayama University, Japan

Izumi Mori, Okayama University, Japan

J. M. Kwak, Kyung Hee University (Seoul, South Korea)

Y. Murata, Okayama University, Japan

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in Plant Biol. (Stuttg.) 15: 436–442 – doi: 10.1111/j.1438-8677.2012.00671.x – Epub 2012 Oct 8 –

https://www.ncbi.nlm.nih.gov/pubmed/23043299

Abstract

We report that two mitogen-activated protein kinases (MAPKs), MPK9 and MPK12, positively regulate abscisic acid (ABA)-induced stomatal closure in Arabidopsis thaliana.

Yeast elicitor (YEL) induced stomatal closure accompanied by intracellular reactive oxygen species (ROS) accumulation and cytosolic free calcium concentration ([Ca(2+) ]cyt ) oscillation.

In this study, we examined whether these two MAP kinases are involved in YEL-induced stomatal closure using MAPKK inhibitors, PD98059 and U0126, and MAPK mutants, mpk9, mpk12 and mpk9 mpk12. Both PD98059 and U0126 inhibited YEL-induced stomatal closure.

YEL induced stomatal closure in the mpk9 and mpk12 mutants but not in the mpk9 mpk12 mutant, suggesting that a MAPK cascade involving MPK9 and MPK12 functions in guard cell YEL signalling. However, YEL induced extracellular ROS production, intracellular ROS accumulation and cytosolic alkalisation in the mpk9, mpk12 and mpk9 mpk12 mutants. YEL induced [Ca(2+) ]cyt oscillations in both wild type and mpk9 mpk12 mutant.

These results suggest that MPK9 and MPK12 function redundantly downstream of extracellular ROS production, intracellular ROS accumulation, cytosolic alkalisation and [Ca(2+) ]cyt oscillation in YEL-induced stomatal closure in Arabidopsis guard cells and are shared with ABA signalling.