Emp10 encodes a mitochondrial PPR protein that affects the cis-splicing of nad2 intron 1 and seed development in maize
Emp10 encodes a mitochondrial PPR protein that affects the cis-splicing of nad2 intron 1 and seed development in maize
复制标题
Emp10 编码线粒体 PPR 蛋白，该蛋白影响 nad2 内含子 1 的顺式剪接和玉米种子发育
DOI：
10.1111/tpj.13551
复制
发表时间：
2017-07-01
期刊：
影响因子：
7.2
通讯作者：
Qiu, Fazhan
中科院分区：
文献类型：
--
作者：
Cai, Manjun;Li, Shuzhen;Qiu, Fazhan
在高等植物中，许多线粒体基因含有II类内含子，这些内含子通过剪接从RNA中去除，产生成熟的转录本，然后翻译成功能蛋白。然而，在玉米中，线粒体内含子剪接的相关因子及其生物学功能尚不清楚。在这里，我们分离出一个空果皮10（emp10）突变体，并确定了潜在的基因图位克隆。Emp10编码具有10个PPR基序的P型靶向三肽重复序列（PPR）蛋白。Emp 10功能的丧失导致nad 2的第一内含子的剪接缺陷，nad 2是编码NADH脱氢酶亚基2（也称为复合物I）的基因。emp10突变体具有检测不到的复合物I活性，并且已经阻止了胚和胚乳的发育，从而导致具有空果皮的缺陷种子。此外，胚乳转移层细胞受到严重影响，表明在emp10籽粒细胞壁向内生长的缺陷。此外，交替呼吸途径涉及交替氧化酶显着诱导的emp10突变体。这些结果表明，EMP10是专门需要的线粒体nad2内含子1的顺式剪接，胚胎发生和胚乳发育在玉米。
In higher plants, many mitochondrial genes contain group II-type introns that are removed from RNAs by splicing to produce mature transcripts that are then translated into functional proteins. However, the factors involved in the splicing of mitochondrial introns and their biological functions are not well understood in maize. Here, we isolated an empty pericarp 10 (emp10) mutant and identified the underlying gene by map-based cloning. Emp10 encodes a P-type mitochondria-targeted pentatricopeptide repeat (PPR) protein with 10 PPR motifs. Loss of Emp10 function results in splicing defect of the first intron of nad2, a gene encoding subunit 2 of NADH dehydrogenase (also called complex I). The emp10 mutant has undetectable activity of complex I and has arrested development of embryo and endosperm, and thus defective seeds with empty pericarp. Additionally, the basal endosperm transfer layer cells were severely affected, indicating the deficiency of cell wall ingrowths in the emp10 kernels. Moreover, the alternative respiratory pathway involving alternative oxidase was significantly induced in the emp10 mutant. These results suggest that EMP10 is specifically required for the cis-splicing of mitochondrial nad2 intron 1, embryogenesis and endosperm development in maize.