Maize Dek37 Encodes a P-type PPR Protein That Affects cis-Splicing of Mitochondrial nad2 Intron 1 and Seed Development
Maize Dek37 Encodes a P-type PPR Protein That Affects cis-Splicing of Mitochondrial nad2 Intron 1 and Seed Development
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玉米 Dek37 编码影响线粒体 nad2 内含子 1 顺式剪接和种子发育的 P 型 PPR 蛋白
DOI：
10.1534/genetics.117.300602
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发表时间：
2018-03-01
期刊：
影响因子：
3.3
通讯作者：
Song, Rentao
中科院分区：
文献类型：
--
作者：
Dai, Dawei;Luan, Shengchao;Song, Rentao
线粒体II组内含子需要许多核编码的一般因子和特定因子的参与才能在体内实现有效的剪接。五肽重复（PPR）蛋白参与辅助II组内含子剪接。在这里，我们鉴定并鉴定了一个新的玉米种子突变体，缺陷核37 (dek37)，它显著延迟了胚乳和胚胎的发育。Dek37编码一种典型的以线粒体为目标的p型PPR蛋白。dek37突变导致突变种子中无法检测到dek37蛋白。线粒体转录本分析表明，dek37突变降低了线粒体nad2内含子1的剪接效率，导致复合物i的组装和NADH脱氢酶活性降低。透射电镜（TEM）显示，dek37突变的线粒体存在严重的形态缺陷。dek37胚乳的转录组分析表明，与线粒体功能相关的替代呼吸途径和广泛的差异表达基因的表达增强。这些结果表明，Dek37参与了线粒体nad2内含子1的顺式剪接，是玉米复合体I组装、线粒体功能和种子发育所必需的。
Mitochondrial group II introns require the participation of numerous nucleus-encoded general and specific factors to achieve efficient splicing in vivo. Pentatricopeptide repeat (PPR) proteins have been implicated in assisting group II intron splicing. Here, we identified and characterized a new maize seed mutant, defective kernel 37 (dek37), which has significantly delayed endosperm and embryo development. Dek37 encodes a classic P-type PPR protein that targets mitochondria. The dek37 mutation causes no detectable DEK37 protein in mutant seeds. Mitochondrial transcripts analysis indicated that dek37 mutation decreases splicing efficiency of mitochondrial nad2 intron 1, leading to reduced assembly and NADH dehydrogenase activity of complex I. Transmission Electron Microscopy (TEM) revealed severe morphological defects of mitochondria in dek37. Transcriptome analysis of dek37 endosperm indicated enhanced expression in the alternative respiratory pathway and extensive differentially expressed genes related to mitochondrial function. These results indicated that Dek37 is involved in cis-splicing of mitochondrial nad2 intron 1 and is required for complex I assembly, mitochondrial function, and seed development in maize.