Deletion of orf352 in Wild Abortive-type cytoplasmic male sterile rice restores pollen starch accumulation but not seed fertility

Cytoplasmic male sterility (CMS) is an agriculturally important trait that plays a crucial role in F1 hybrid seed production. In CMS plants, the CMS-causing gene is located in the mitochondria, and its ectopic expression leads to male sterility. In rice, the Wild Abortive (WA)-type CMS (WAA) has been successfully utilized for commercial F1 hybrid seed production. Based on comparisons of mitochondrial genome sequences, open reading frame 352 (orf352) has been identified as a CMS-associated gene. Recently, a mitochondrial genome-editing tool, mitochondria-targeted transcription activator-like effector nucleases (mitoTALENs), has been shown to be effective for identifying mitochondrial CMS-causing genes.