A novel tetratricopeptide repeat protein, WHITE TO GREEN1, is required for early chloroplast development and affects RNA editing in chloroplasts

Corresponding author: Sodmergen

The chloroplast is essential for plant photosynthesis and production, but the regulatory mechanism of chloroplast development is still elusive. Here, a novel gene, WHITE TO GREEN1 (WTG1), was identified to have a function in chloroplast development and plastid gene expression by screening Arabidopsis leaf coloration mutants. WTG1 encodes a chloroplast-localized tetratricopeptide repeat (三十四肽重复序列, TPR) protein that is expressed widely in Arabidopsis cells. Disruption of WTG1 suppresses plant growth, retards (阻碍) leaf greening and chloroplast development, and represses photosynthetic gene expression, but complemented expression of WTG1 restored a normal phenotype. Moreover, WTG1 protein is associated with the organelle RNA editing factors MORF8 and MORF9, and RNA editing of the plastid petL-5 and ndhG-50 transcripts was affected in wtg1 mutants. These results indicate that WTG1 affects both transcriptional and posttranscriptional regulation of plastid gene expression, and provide evidence for the involvement of a tetratricopeptide repeat protein in chloroplast RNA editing in Arabidopsis.

叶绿体对于植物的光合和产量都是必须的，但叶绿体发育的调控机制仍然不清楚。本文通过扫描拟南芥叶色突变体鉴定了一个新的基因WTG1，其在叶绿体发育和质体基因表达发面发挥功能。WTG1编码了一个定位于叶绿体的三十四肽重复序列TPR蛋白，在广泛的拟南芥细胞中表达。WTG1基因的破坏会抑制植物生长，阻碍叶片变绿及叶绿体的发育，并抑制光和基因的表达，但互补WTG1基因后会恢复突变体表型。此外，WTG1蛋白与细胞器RNA编辑因子MORF8和MORF9相关联，质体petL-5和ndhG-50转录本的RNA编辑在wtg1突变体中受到影响。这些结果表明WTG1同时影响质体基因表达的转录和转录后调控，为拟南芥中通过TRP蛋白参与叶绿体RNA编辑的调控提供新的见解。

个人简介：1979 - 1983年, 理学学士 , 北京大学生物系；1985 - 1988年, 农学硕士 , 日本东京大学；1988 - 1991年, 农学博士 , 日本东京大学；1991 - 1994年, 副教授 , 北京大学生命科学学院；1994 - 1999年, 副教授 , 北京大学生命科学学院；1999 - 至今, 教授 , 北京大学生命科学学院。

doi: https://doi.org/10.1093/jxb/erx383