Mitochondrial localization of ORF346 causes pollen abortion in alloplasmic male sterility
Shifei Sang,
Hongtao Cheng,
Mengyu Hao,
Bingli Ding,
Desheng Mei,
Hui Wang,
Wenxiang Wang,
Jia Liu,
Li Fu,
Kede Liu,
Qiong Hu
Affiliations
Shifei Sang
Oil Crops Research Institute of Chinese Academy of Agricultural Sciences/Key Laboratory for Biological Sciences and Genetic Improvement of Oil Crops, Ministry of Agriculture and Rural Affairs, Wuhan 430062, Hubei, China; National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, Hubei, China
Hongtao Cheng
Oil Crops Research Institute of Chinese Academy of Agricultural Sciences/Key Laboratory for Biological Sciences and Genetic Improvement of Oil Crops, Ministry of Agriculture and Rural Affairs, Wuhan 430062, Hubei, China
Mengyu Hao
Oil Crops Research Institute of Chinese Academy of Agricultural Sciences/Key Laboratory for Biological Sciences and Genetic Improvement of Oil Crops, Ministry of Agriculture and Rural Affairs, Wuhan 430062, Hubei, China
Bingli Ding
Oil Crops Research Institute of Chinese Academy of Agricultural Sciences/Key Laboratory for Biological Sciences and Genetic Improvement of Oil Crops, Ministry of Agriculture and Rural Affairs, Wuhan 430062, Hubei, China
Desheng Mei
Oil Crops Research Institute of Chinese Academy of Agricultural Sciences/Key Laboratory for Biological Sciences and Genetic Improvement of Oil Crops, Ministry of Agriculture and Rural Affairs, Wuhan 430062, Hubei, China
Hui Wang
Oil Crops Research Institute of Chinese Academy of Agricultural Sciences/Key Laboratory for Biological Sciences and Genetic Improvement of Oil Crops, Ministry of Agriculture and Rural Affairs, Wuhan 430062, Hubei, China
Wenxiang Wang
Oil Crops Research Institute of Chinese Academy of Agricultural Sciences/Key Laboratory for Biological Sciences and Genetic Improvement of Oil Crops, Ministry of Agriculture and Rural Affairs, Wuhan 430062, Hubei, China
Jia Liu
Oil Crops Research Institute of Chinese Academy of Agricultural Sciences/Key Laboratory for Biological Sciences and Genetic Improvement of Oil Crops, Ministry of Agriculture and Rural Affairs, Wuhan 430062, Hubei, China
Li Fu
Oil Crops Research Institute of Chinese Academy of Agricultural Sciences/Key Laboratory for Biological Sciences and Genetic Improvement of Oil Crops, Ministry of Agriculture and Rural Affairs, Wuhan 430062, Hubei, China
Kede Liu
National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, Hubei, China
Qiong Hu
Oil Crops Research Institute of Chinese Academy of Agricultural Sciences/Key Laboratory for Biological Sciences and Genetic Improvement of Oil Crops, Ministry of Agriculture and Rural Affairs, Wuhan 430062, Hubei, China; Corresponding author.
The Nsa cytoplasmic male sterility (CMS) system confers stable male sterility and offers great potential for production of hybrid seeds in oilseed rape. However, genes responsible for male sterility in Nsa CMS have not been identified. By mitochondrial genome sequencing of Nsa CMS and its maintainer line, we identified in an Nsa CMS line several chimeric genes encoding hypothetical proteins harboring transmembrane domains. One novel chimeric gene orf346 showed high identity with cox1 at the 5′ terminal region and was co-transcribed with nad3 and rps12 genes. Transgenic plants of orf346 fused with or without mitochondrial targeting peptide conferred complete male sterility in Arabidopsis. ORF346 was mitochondrion-localized. Expression of orf346 in Escherichia coli inhibited bacterial growth, with excessive accumulation of reactive oxygen species and decreased ATP content. These results reveal a link between the newly identified mitochondrial gene orf346 and the abortion of Nsa CMS. Inadequate energy supply and excessive accumulation of reactive oxygen species may account for pollen abortion in Nsa CMS plants.
