一个细胞核定位PPR蛋白OsNPPR2在水稻种子发育中起重要作用  

A nucleus-localized PPR protein OsNPPR2 is important for seed development in rice

作　　者：毕梦蕾 唐小涵 王云龙[1] 段二超 滕烜[1] 张元燕 江玲[1] 张文伟[1] 王益华[1] 万建民 BI Menglei;TANG Xiaohan;WANG Yunlong;DUAN Erchao;TENG Xuan;ZHANG Yuanyan;JIANG Ling;ZHANG Wenwei;WANG Yihua;WAN Jianmin(State Key Laboratory of Crop Genetics and Germplasm Enhancement,Nanjing Agricultural University,Key Laboratory of Biology,Genetics and Breeding of japonica Rice in Mid-lower Yangtze River,Ministry of Agriculture and Rural Affairs,The Yangtze River Valley Hybrid Rice Collaboration Innovation Center,Jiangsu Collaboration Innovation Center for Modern Crop Production,Nanjing 210095,China)

机构地区：[1]南京农业大学作物遗传与种质创新国家重点实验室农业农村部长江中下游粳稻生物学与遗传育种重点实验室长江流域杂交水稻协同创新中心江苏省现代作物生产中心,南京210095

出　　处：《植物生理学报》2020年第4期789-798,共10页Plant Physiology Journal

基　　金：国家转基因生物新品种培育重大专项(2016ZX08001006);国家重点研发计划项目(2017YFD0100400);江苏省重点研发项目(BE2018388)。

摘　　要：PPR (pentatricopeptide repeat)蛋白主要定位于叶绿体和线粒体中,调控其RNA的编辑和剪接,但目前人们对核定位的PPR蛋白的功能知之甚少。本研究利用甲基磺酸乙酯(EMS)处理水稻(Oryza sativa)‘宁粳4号’获得胚乳缺陷突变体f29,突变体成熟种子呈粉质且不能正常萌发。通过图位克隆得到一个新的水稻中细胞核定位的PPR蛋白,命名为OsNPPR2。由于OsNPPR2的功能缺陷导致水稻种子线粒体复合体I亚基nad1第一个内含子中714 bp的片段未被剪切掉,线粒体结构和功能异常,呼吸途径受损,进而产生胚致死和胚乳粉质皱缩的表型。本研究发现OsNPPR2通过影响线粒体的功能调控水稻种子的发育。PPR(pentatricopeptide repeat) proteins are mainly localized in chloroplasts and mitochondria and regulate the editing and splicing of organellar RNA. However, the functions of the nucleus-localized PPR proteins remain largely unknown. In this study, an endosperm-defective mutant f29 was obtained from the mutant library of rice(Oryza sativa) cv. Ningjing 4 induced with ethyl methane sulfonate(EMS). Mature seeds of f29 are opaque and floury. Map-based cloning showed the mutant phenotype was caused by a single nucleotide substitution in the coding region of Os01g0908800 which encodes a nucleus-localized PPR protein and we named it OsNPPR2. Transcription of nad1 in f29 was abnormal and sequencing analyses showed that a 714 bp fragment in the first intron of nad1 was not cleaved. Nad1 is a subunit of complex I in mitochondria. The functional defects of OsNPPR2 lead to abnormal mitochondrial structure, impaired respiratory pathway and seriously delayed growth in rice seeds, resulting in the opaque endosperm and embryo lethality. Therefore, OsNPPR2 is essential for rice seed development.

关 键 词：水稻 粉质胚乳 PPR蛋白 RNA剪接 种子发育 

分 类 号：S511[农业科学—作物学]