摘要
Organisms can adjust their phenotype in response to changing environmental conditions. This phenomenon is termed phenotypic plasticity. Despite its ubiquitous occurrence, there has been very little study on the molecular mechanism of phenotypic plasticity. In this study, we isolated a rice （Oryza sativa L.） mutant, rice plasticity 1 （rpl1）, that displayed increased environment-dependent phenotypic variations. RPL1 was expressed in all tissues examined. The protein was localized in the nucleus and its distribution in the nucleus overlapped with heterochromatin. The rpll mutation led to an increase in DNA methylation on repetitive sequences and a decrease in overall histone acetylation. In addition, the mutation affected responses of the rice plant to phytohormones such as brassinosteroid, gibberellin, and cytokinin. Analysis of the putative rice brassinosteroid receptor OsBRI1, a key hormone signaling gene, indicated that RPL1 may be involved in the regulation of epigenomic modification of the gene. These data suggest that RPL1 regulated phenotypic plasticity likely through its involvement in epigenetic processes affecting responses of the plant to phytohormones.
Organisms can adjust their phenotype in response to changing environmental conditions. This phenomenon is termed phenotypic plasticity. Despite its ubiquitous occurrence, there has been very little study on the molecular mechanism of phenotypic plasticity. In this study, we isolated a rice （Oryza sativa L.） mutant, rice plasticity 1 （rpl1）, that displayed increased environment-dependent phenotypic variations. RPL1 was expressed in all tissues examined. The protein was localized in the nucleus and its distribution in the nucleus overlapped with heterochromatin. The rpll mutation led to an increase in DNA methylation on repetitive sequences and a decrease in overall histone acetylation. In addition, the mutation affected responses of the rice plant to phytohormones such as brassinosteroid, gibberellin, and cytokinin. Analysis of the putative rice brassinosteroid receptor OsBRI1, a key hormone signaling gene, indicated that RPL1 may be involved in the regulation of epigenomic modification of the gene. These data suggest that RPL1 regulated phenotypic plasticity likely through its involvement in epigenetic processes affecting responses of the plant to phytohormones.
基金
This work was supported by grants from the 863 Project （SS2012AA100103） and the National Natural Science Foundation of China （30921091）. ACKNOWLEDGMENTS We thank Professor Dao-Xiu Zhou for reading many earlier versions of this manuscript and giving helpful comments. The confocal images acquired with the Zeiss LSM 510 Meta confocal microscope were done with assistance of Yao Xiao in Ligeng Ma＇s lab at the National Institute of Biological Sciences, Beijing. We acknowledge Professor Jian Xu for the pM999-ECFP and pM999-SUNLIGHTGFP vectors. No conflict of interest declared.
