Zhu Xiaobo, Liang Sihui, Yin Junjie, Yuan Can, Wang Jing, Li Weitao, He Min, Wang Jichun, Chen Weilan, Ma Bingtian, Wang Yuping, Qin Peng, Li Shigui, Chen Xuewei
Rice Research Institute, Key Laboratory of Major Crop Diseases, Sichuan Agricultural University at Wenjiang, Chengdu, Sichuan 611130, China; State Key Laboratory of Hybrid Rice, Collaborative Innovation Center for Hybrid Rice in Yangtze River Basin at Sichuan, Chengdu 611130, China.
Rice Research Institute, Key Laboratory of Major Crop Diseases, Sichuan Agricultural University at Wenjiang, Chengdu, Sichuan 611130, China; State Key Laboratory of Hybrid Rice, Collaborative Innovation Center for Hybrid Rice in Yangtze River Basin at Sichuan, Chengdu 611130, China.
Gene. 2015 Dec 10;574(1):11-9. doi: 10.1016/j.gene.2015.07.067. Epub 2015 Jul 22.
DnaJ proteins belong to chaperones of Hsp40 family that ubiquitously participate in various cellular processes. Previous studies have shown chloroplast-targeted DnaJs are involved in the development of chloroplast in some plant species. However, little is known about the function of DnaJs in rice, one of the main staple crops. In this study, we characterized a type I DnaJ protein OsDjA7/8. We found that the gene OsDjA7/8 was expressed in all collected tissues, with a priority in the vigorous growth leaf. Subcellular localization revealed that the protein OsDjA7/8 was mainly distributed in chloroplast. Reduced expression of OsDjA7/8 in rice led to albino lethal at the seedling stage. Transmission electron microscopy observation showed that the chloroplast structures were abnormally developed in the plants silenced for OsDjA7/8. In addition, the transcriptional expression of the genes tightly associated with the development of chloroplast was deeply reduced in the plants silenced for OsDjA7/8. Collectively, our study reveals that OsDjA7/8 encodes a chloroplast-localized protein and is essential for chloroplast development and differentiation in rice.
DnaJ蛋白属于Hsp40家族的伴侣蛋白，广泛参与各种细胞过程。先前的研究表明，靶向叶绿体的DnaJ蛋白在一些植物物种的叶绿体发育中发挥作用。然而，对于主要粮食作物之一水稻中DnaJ蛋白的功能却知之甚少。在本研究中，我们对一种I型DnaJ蛋白OsDjA7/8进行了表征。我们发现基因OsDjA7/8在所有采集的组织中均有表达，在生长旺盛的叶片中表达尤为突出。亚细胞定位显示，蛋白OsDjA7/8主要分布在叶绿体中。水稻中OsDjA7/8表达降低导致幼苗期白化致死。透射电子显微镜观察表明，沉默OsDjA7/8的植株中叶绿体结构发育异常。此外，在沉默OsDjA7/8的植株中，与叶绿体发育紧密相关的基因的转录表达大幅降低。总的来说，我们的研究表明，OsDjA7/8编码一种定位于叶绿体的蛋白，对水稻叶绿体的发育和分化至关重要。
