Chloroplast RNA-Binding Protein RBD1 Promotes Chilling Tolerance through 23S rRNA Processing in Arabidopsis

PLoS Genet. 2016 May 3;12(5):e1006027. doi: 10.1371/journal.pgen.1006027. eCollection 2016 May.

Abstract

Plants have varying abilities to tolerate chilling (low but not freezing temperatures), and it is largely unknown how plants such as Arabidopsis thaliana achieve chilling tolerance. Here, we describe a genome-wide screen for genes important for chilling tolerance by their putative knockout mutants in Arabidopsis thaliana. Out of 11,000 T-DNA insertion mutant lines representing half of the genome, 54 lines associated with disruption of 49 genes had a drastic chilling sensitive phenotype. Sixteen of these genes encode proteins with chloroplast localization, suggesting a critical role of chloroplast function in chilling tolerance. Study of one of these proteins RBD1 with an RNA binding domain further reveals the importance of chloroplast translation in chilling tolerance. RBD1 is expressed in the green tissues and is localized in the chloroplast nucleoid. It binds directly to 23S rRNA and the binding is stronger under chilling than at normal growth temperatures. The rbd1 mutants are defective in generating mature 23S rRNAs and deficient in chloroplast protein synthesis especially under chilling conditions. Together, our study identifies RBD1 as a regulator of 23S rRNA processing and reveals the importance of chloroplast function especially protein translation in chilling tolerance.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adaptation, Physiological / genetics
  • Arabidopsis / genetics*
  • Arabidopsis / growth & development
  • Arabidopsis Proteins / genetics*
  • Chloroplasts / genetics*
  • Cold Temperature / adverse effects
  • Gene Expression Regulation, Plant
  • Genome, Plant
  • Mutation
  • Phenotype
  • Photosynthesis / genetics
  • Plant Leaves / genetics
  • Plant Leaves / growth & development
  • RNA Processing, Post-Transcriptional / genetics
  • RNA, Ribosomal, 23S / genetics*
  • RNA-Binding Proteins / biosynthesis
  • RNA-Binding Proteins / genetics*
  • Ribonucleoproteins / biosynthesis
  • Ribonucleoproteins / genetics

Substances

  • Arabidopsis Proteins
  • RBD1 protein, Arabidopsis
  • RNA, Ribosomal, 23S
  • RNA-Binding Proteins
  • Ribonucleoproteins

Grants and funding

This work is supported by grants from National Science Foundation (http://www.nsf.gov/) (IOS-1353738) to J Hua and Chinese Academy of Sciences (http://english.cas.cn/) to JK Zhu. Shuai Wang is supported by China Scholarship Council (http://en.csc.edu.cn/) and G Bai is supported by YNTC-2015YN09 (http://www.yntsti.com/) and CNTC-110201503006 (http://www.tobacco.gov.cn/html/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.