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Two guard cell mitogen‐activated protein kinases, MPK 9 and MPK 12, function in methyl jasmonate‐induced stomatal closure in Arabidopsis thaliana
Author(s) -
Khokon Md. A. R.,
Salam M. A.,
Jammes F.,
Ye W.,
Hossain M. A.,
Uraji M.,
Nakamura Y.,
Mori I. C.,
Kwak J. M.,
Murata Y.
Publication year - 2015
Publication title -
plant biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.871
H-Index - 87
eISSN - 1438-8677
pISSN - 1435-8603
DOI - 10.1111/plb.12321
Subject(s) - guard cell , biology , microbiology and biotechnology , arabidopsis , methyl jasmonate , mutant , cytosol , kinase , wild type , mapk/erk pathway , protein kinase a , arabidopsis thaliana , abscisic acid , biochemistry , gene , enzyme
Methyl jasmonate (Me JA ) and abscisic acid ( ABA ) signalling cascades share several signalling components in guard cells. We previously showed that two guard cell‐preferential mitogen‐activated protein kinases ( MAPK s), MPK 9 and MPK 12 , positively regulate ABA signalling in Arabidopsis thaliana . In this study, we examined whether these two MAP kinases function in Me JA signalling using genetic mutants for MPK 9 and MPK 12 combined with a pharmacological approach. Me JA induced stomatal closure in mpk9‐1 and mpk12‐1 single mutants as well as wild‐type plants, but not in mpk9‐1 mpk12‐1 double mutants. Consistently, the MAPKK inhibitor PD 98059 inhibited the Me JA ‐induced stomatal closure in wild‐type plants. Me JA elicited reactive oxygen species ( ROS ) production and cytosolic alkalisation in guard cells of the mpk9‐1, mpk12‐1 and mpk9‐1 mpk12‐1 mutants, as well in wild‐type plants. Furthermore, Me JA triggered elevation of cytosolic Ca 2+ concentration ([Ca 2+ ] cyt ) in the mpk9‐1 mpk12‐1 double mutant as well as wild‐type plants. Activation of S‐type anion channels by Me JA was impaired in mpk9‐1 mpk12‐1 . Together, these results indicate that MPK 9 and MPK 12 function upstream of S‐type anion channel activation and downstream of ROS production, cytosolic alkalisation and [Ca 2+ ] cyt elevation in guard cell Me JA signalling, suggesting that MPK 9 and MPK 12 are key regulators mediating both ABA and Me JA signalling in guard cells.