Mitogen-Activated Protein Kinase Phosphatases Affect UV-B-Induced Stomatal Closure via Controlling NO in Guard Cells.
Ultraviolet B (UV-B) radiation induces the activation of MITOGEN-ACTIVATED PROTEIN KINASE PHOSPHATASE1 (MKP1) and its targets MPK3 and MPK6, but whether they participate in UV-B guard cell signaling is not clear. Here, evidence shows that UV-B-induced stomatal closure in Arabidopsis (Arabidopsis thaliana) is antagonistically regulated by MKP1 and MPK6 via modulating hydrogen peroxide (H2O2)-induced nitric oxide (NO) production in guard cells. The mkp1 mutant was hypersensitive to UV-B-induced stomatal closure and NO production in guard cells but not to UV-B-induced H2O2production, suggesting that MKP1 negatively regulates UV-B-induced stomatal closure via inhibiting NO generation in guard cells. Moreover, MPK3 and MPK6 were activated by UV-B in leaves of the wild type and hyperactivated in the mkp1 mutant, but the UV-B-induced activation of MPK3 and MPK6 was largely inhibited in mutants for ATRBOHD and ATRBOHF but not in mutants for NIA1 and NIA2 mpk6 mutants showed defects of UV-B-induced NO production and stomatal closure but were normal in UV-B-induced H2O2production, while stomata of mpk3 mutants responded to UV-B just like those of the wild type. The defect of UV-B-induced stomatal closure in mpk6 mutants was rescued by exogenous NO but not by exogenous H2O2Furthermore, double mutant mkp1/mpk6 and the single mutant mpk6 showed the same responses to UV-B in terms of either stomatal movement or H2O2and NO production. These data indicate that MPK6, but not MPK3, positively regulates UV-B-induced stomatal closure via acting downstream of H2O2and upstream of NO, while MKP1 functions negatively in UV-B guard cell signaling via down-regulation of MPK6.
School of Life Sciences, Shaanxi Normal University, Xi'an 710062, China.
Feng-Chen
0000-0003-2945-085X
FC
Li
School of Life Sciences, Shaanxi Normal University, Xi'an 710062, China.
Jing
0000-0002-2876-7794
J
Wang
School of Life Sciences, Shaanxi Normal University, Xi'an 710062, China.
Mi-Mi
MM
Wu
School of Life Sciences, Shaanxi Normal University, Xi'an 710062, China.
Cai-Ming
CM
Fan
School of Life Sciences, Shaanxi Normal University, Xi'an 710062, China.
Xuan
X
Li
School of Life Sciences, Shaanxi Normal University, Xi'an 710062, China hejm@snnu.edu.cn.
Jun-Min
0000-0001-8869-9618
JM
He
D017360:Arabidopsis / Q000166:cytology / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D006861:Hydrogen Peroxide / Q000378:metabolism; D020929:Mitogen-Activated Protein Kinase Kinases / Q000235:genetics / Q000378:metabolism; D054639:Mitogen-Activated Protein Kinase Phosphatases / Q000235:genetics / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D019255:NADPH Oxidases / Q000235:genetics / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D059828:Plant Cells / Q000378:metabolism / Q000528:radiation effects; D054046:Plant Stomata / Q000502:physiology* / Q000528:radiation effects; D017027:Protein Tyrosine Phosphatases / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D014466:Ultraviolet Rays
D029681:Arabidopsis Proteins; D006861:Hydrogen Peroxide; D020929:Mitogen-Activated Protein Kinase Kinases; D054639:Mitogen-Activated Protein Kinase Phosphatases; D020928:Mitogen-Activated Protein Kinases; D019255:NADPH Oxidases; D009569:Nitric Oxide; D017027:Protein Tyrosine Phosphatases; C568857:AT5G47910 protein, Arabidopsis; C458516:AtMPK3 protein, Arabidopsis; C436293:MPK6 protein, Arabidopsis; C499612:MKP1 protein, Arabidopsis; C000589475:RBOH F protein, Arabidopsis