Liang Wang1, Wenwei Zhang1, Shijia Liu1, Yunlu Tian1, Xi Liu1, Haigang Yan1, Yue Cai1, Xuan Teng1, Hui Dong1, Rongbo Chen1, Xiaokang Jiang1, Yihua Wang2, Jianmin Wan3,4. 1. State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, China. 2. State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, China. yihuawang@njau.edu.cn. 3. State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, China. wanjm@njau.edu.cn. 4. National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, China. wanjm@njau.edu.cn.
Abstract
BACKGROUND: The sequences of several important mitochondrion-encoded genes involved in respiration in higher plants are interrupted by introns. Many nuclear-encoded factors are involved in splicing these introns, but the mechanisms underlying this splicing remain unknown. RESULTS: We isolated and characterized a rice mutant named floury shrunken endosperm 5 (fse5). In addition to having floury shrunken endosperm, the fse5 seeds either failed to germinate or produced seedlings which grew slowly and died ultimately. Fse5 encodes a putative plant organelle RNA recognition (PORR) protein targeted to mitochondria. Mutation of Fse5 hindered the splicing of the first intron of nad4, which encodes an essential subunit of mitochondrial NADH dehydrogenase complex I. The assembly and NADH dehydrogenase activity of complex I were subsequently disrupted by this mutation, and the structure of the mitochondria was abnormal in the fse5 mutant. The FSE5 protein was shown to interact with mitochondrial intron splicing factor 68 (MISF68), which is also a splicing factor for nad4 intron 1 identified previously via yeast two-hybrid (Y2H) assays. CONCLUSION: Fse5 which encodes a PORR domain-containing protein, is essential for the splicing of nad4 intron 1, and loss of Fse5 function affects seed development and seedling growth.
BACKGROUND: The sequences of several important mitochondrion-encoded genes involved in respiration in higher plants are interrupted by introns. Many nuclear-encoded factors are involved in splicing these introns, but the mechanisms underlying this splicing remain unknown. RESULTS: We isolated and characterized a rice mutant named floury shrunken endosperm 5 (fse5). In addition to having floury shrunken endosperm, the fse5 seeds either failed to germinate or produced seedlings which grew slowly and died ultimately. Fse5 encodes a putative plant organelle RNA recognition (PORR) protein targeted to mitochondria. Mutation of Fse5 hindered the splicing of the first intron of nad4, which encodes an essential subunit of mitochondrial NADH dehydrogenase complex I. The assembly and NADH dehydrogenase activity of complex I were subsequently disrupted by this mutation, and the structure of the mitochondria was abnormal in the fse5 mutant. The FSE5 protein was shown to interact with mitochondrial intron splicing factor 68 (MISF68), which is also a splicing factor for nad4 intron 1 identified previously via yeast two-hybrid (Y2H) assays. CONCLUSION: Fse5 which encodes a PORR domain-containing protein, is essential for the splicing of nad4 intron 1, and loss of Fse5 function affects seed development and seedling growth.
Authors: Catherine Colas des Francs-Small; Andéol Falcon de Longevialle; Yunhai Li; Elizabeth Lowe; Sandra K Tanz; Caroline Smith; Michael W Bevan; Ian Small Journal: Plant Physiol Date: 2014-06-23 Impact factor: 8.340