|ZHANG, JUNXIANG - Cornell University|
|YUAN, HUI - Cornell University|
|LYI, SANGBOM - Cornell University|
|Thannhauser, Theodore - Ted|
|ZHANG, LUGANG - Northwest Agricultural & Forestry University|
Submitted to: Journal of Experimental Botany
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/10/2015
Publication Date: 3/22/2016
Citation: Zhang, J., Yuan, H., Yang, Y., Fish, T., Lyi, S., Thannhauser, T.W., Zhang, L., Li, L. 2016. Plastid ribosomal protein S5 plays a critical role in photosynthesis, plant development, and cold stress tolerance in arabidopsis. Journal of Experimental Botany. doi: 10.1093/jxb/erw106.
Interpretive Summary: Plastid ribosomal proteins as essential components of chloroplast protein synthesis machinery exert diverse roles in plant growth and development. Despite significant achievements in this area of research, how plastid ribosomal proteins regulate these processes is not fully understood and the function of some individual plastid ribosomal proteins remain largely unknown. In this study, we report the isolation and functional characterization of a unique plastid ribosomal protein gene (RPS5) in Arabidopsis. We show that a missense mutation of RPS5 causes serious impairment of chloroplast 16S rRNA processing and accumulation, and has profound effects on the accumulation of a large number of the photosystem I and II proteins and plastid ribosomal proteins in affecting photosynthesis and plant development. Moreover, we discover that PRPS5 mediates cold stress tolerance, a trait important for agricultural production. Our data reveal a critical role of PRPS5 in modulating plastid ribosome assembly and in affecting plant development and abiotic stress tolerance in plants.
Technical Abstract: Plastid ribosomal proteins (RPs) are essential components for protein synthesis machinery and exert diverse roles in plant growth and development. Mutations in plastid RPs lead to a range of developmental phenotypes in plants. However, how they regulate these processes is not fully understood and the functions of some individual plastid RPs remain unknown. To identify genes responsible for chloroplast development and pigment synthesis, we isolated and characterized a mutant that exhibited pale-yellow inner leaves and reduced growth rate in Arabidopsis. The mutant contained a missense mutation of plastid ribosomal protein S5 (rps5-1), which caused a dramatically reduced abundance of chloroplast 16S rRNA and seriously impaired 16S rRNA processing to affect the assembly and/or stability of chloroplast 30S subunit for ribosome function and plastid translation. Comparative proteomics analysis revealed that the RPS5 mutation specifically suppressed expression of a large number of core components involved in photosystem I and II as well as many plastid ribosomal proteins. Unexpectedly, a number of proteins associated with cold stress responses were greatly decreased in rps5-1, and overexpression of the plastid RPS5 improved cold tolerance of the transgenic plants. Our results indicate that RPS5 is a critical composition in the plastid 30S subunit and plays a specific role in affecting proteins involved in photosynthesis and cold stress responses to mediate plant growth and development.