Restores fertility in rice varieties with LD-type cytoplasmic male sterility (CMS) (PubMed:21265890). CMS is caused by genetic incompatibility between nuclei and mitochondria within male reproductive organs (PubMed:21265890). Corresponds to the functional allele of RF2, which is dependent of the presence of ILE-78 in the japonica cultivars Fukuyama and Owarihatamochi (AC F1SZ42), and indica cultivar Kasalath (AC F1SZ41) (PubMed:21265890). Non-functional RF2 alleles are found in japonica cultivars Taichung 65 and Nipponbare (AC F1SZ44), where ILE-78 is replaced by THR-78 (PubMed:21265890). Specifically expressed during anther development, from the uninucleate pollen stage to the tricellular pollen stage, with the highest expression at the tricellular pollen stage.