State Key Laboratory of Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, China.
National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agriculture Sciences, Beijing, 100081, China.
Plant Mol Biol. 2019 Aug;100(6):635-645. doi: 10.1007/s11103-019-00885-z. Epub 2019 May 30.
Rice WSL6 is involved in chloroplast ribosome biogenesis and is essential for early chloroplast development. Construction of the genetic translation system is a prerequisite for chloroplast development in plants. However, the molecular mechanism underlying this process is largely unknown. Here, we isolated a white stripe leaf6 (wsl6) mutant in rice. The mutant seedlings displayed white-striped leaves that were more severe under low-temperature conditions. Transmission electron microscopy analysis showed that the wsl6 mutant was defective in early chloroplast development. Map-based cloning revealed that WSL6 encodes an Era-type guanosine-5'-triphosphate (GTP)-binding protein located in chloroplasts. Immunoblotting and quantitative real-time polymerase chain reaction (qRT-PCR) analyses demonstrated an absence of 70S ribosomes in wsl6 chloroplasts. Further research showed that WSL6 binds to the 16S ribosomal RNA (rRNA) subunit of chloroplast ribosome 30S. In summary, these results show that WSL6 is essential for chloroplast ribosome biogenesis during early chloroplast development in rice.
水稻 WSL6 参与叶绿体核糖体生物发生，对早期叶绿体发育至关重要。构建遗传翻译系统是植物叶绿体发育的前提。然而，这一过程的分子机制在很大程度上尚不清楚。在这里，我们分离到一个水稻的白条纹叶 6（wsl6）突变体。该突变体幼苗表现出白条纹叶片，在低温条件下更为严重。透射电子显微镜分析表明，wsl6 突变体在早期叶绿体发育中存在缺陷。基于图谱的克隆表明，WSL6 编码一种位于叶绿体中的 Era 型鸟苷-5'-三磷酸（GTP）结合蛋白。免疫印迹和定量实时聚合酶链反应（qRT-PCR）分析表明，wsl6 叶绿体中不存在 70S 核糖体。进一步的研究表明，WSL6 与叶绿体核糖体 30S 的 16S 核糖体 RNA（rRNA）亚基结合。总之，这些结果表明，WSL6 对于水稻早期叶绿体发育过程中的叶绿体核糖体生物发生是必不可少的。
