Plant and Cell Physiology Advance Access published online on January 11, 2007
Plant and Cell Physiology, doi:10.1093/pcp/pcm007
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
A calmodulin-binding mitogen-activated protein kinase phosphatase is induced by wounding and regulates the activities of stress-related mitogen-activated protein kinases in rice
1National Institute of Agrobiological Sciences, Tsukuba, Ibaraki 305-8602, Japan
2Program for Promotion of Basic Research Activities for Innovative Biosciences, Minato-ku, Tokyo 105-0001, Japan
* Corresponding author: Yuko Ohashi, Kannondai 2-1-2, Tsukuba, Ibaraki 305-8602, Japan, Telephone : +81-29-838-7440, Fax, +81-29-838-7469, E-mail: yohashi{at}affrc.go.jp
| Abstract |
|---|
The mitogen-activated protein kinase (MAPK) phosphatases (MKPs) are negative regulators of MAPKs. In dicotyledons such as Arabidopsis and tobacco, MKPs have been shown to play pivotal roles in abiotic stress responses, hormone responses, and microtubule organization. However, little is known about the role of MKPs in monocotyledons such as rice. Database searches identified five putative MKPs in rice. We investigated their expression in response to wounding, and found that the expression of OsMKP1 is rapidly induced by wounding. In this study, we functionally characterized the involvement of OsMKP1 in wound responses. The deduced amino acid sequence of OsMKP1 shows strong similarity to Arabidopsis AtMKP1 and tobacco NtMKP1. Moreover, OsMKP1 bound calmodulin in a manner similar to NtMKP1. To determine the biological function of OsMKP1, we obtained osmkp1, a loss-of-function mutant, in which retrotransposon Tos17 was inserted in the second exon of OsMKP1. Unlike the Arabidopsis atmkp1 loss-of-function mutant, which shows no abnormal phenotype without stimuli, osmkp1 showed a semi-dwarf phenotype. Exogenous supply of neither gibberellin nor brassinosteroid complemented the semi-dwarf phenotype of osmkp1. Activities of two stress-responsive MAPKs, OsMPK3 and OsMPK6, in osmkp1 were higher than those in the wild-type both before and after wounding. Microarray analysis identified 13 up-regulated and 8 down-regulated genes in osmkp1. Among the up-regulated genes, the expression of five genes showed clear responses to wounding, indicating that wound responses are constitutively activated in osmkp1. These results suggest that OsMKP1 is involved in the negative regulation of rice wound responses.
Keywords: MAPK - MAPK phosphatase - Oryza sativa - phosphorylation - wound
3 Present address: Department of Wood Properties, Forestry and Forest Products Research Institute, Tsukuba, Ibaraki 305-8687, Japan
4 Present address: Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara 630-0101, Japan
![]()
CiteULike
Connotea
Del.icio.us What's this?
This article has been cited by other articles:
![]() |
S. Bartels, J. C. Anderson, M. A. Gonzalez Besteiro, A. Carreri, H. Hirt, A. Buchala, J.-P. Metraux, S. C. Peck, and R. Ulm MAP KINASE PHOSPHATASE1 and PROTEIN TYROSINE PHOSPHATASE1 Are Repressors of Salicylic Acid Synthesis and SNC1-Mediated Responses in Arabidopsis PLANT CELL, September 1, 2009; 21(9): 2884 - 2897. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Lee, E. H. Song, H. S. Kim, J. H. Yoo, H. J. Han, M. S. Jung, S. M. Lee, K. E. Kim, M. C. Kim, M. J. Cho, et al. Regulation of MAPK Phosphatase 1 (AtMKP1) by Calmodulin in Arabidopsis J. Biol. Chem., August 29, 2008; 283(35): 23581 - 23588. [Abstract] [Full Text] [PDF] |
||||

