Comparative analysis of male sterility associated ATPase isoenzymes and atpA genes in a Welsh onion (Allium fistulosum L.) cytoplasmic male sterility line and its maintainer line

Cytoplasmic male sterility (CMS) is a maternally inherited trait characterized by the inability to produce functional pollen and is important for exploiting heterosis in crop plants, but the molecular mechanisms of CMS and fertility restoration remain poorly understood in Welsh onion. Some CMS-associated genes were previously identified by RNA-Seq as candidate genes mediating male sterility in Welsh onion. In this study, the ATPase isoenzyme and ATPase activity were investigated. We also performed 2-dimensional electrophoresis to screen for ATPase-related proteins. The ATP synthase subunit alpha was found to be specifically expressed in the CMS line. Furthermore, we found that the full length of the atpA coding sequence was the same length in the CMS line and its maintainer line, but single nucleotide polymorphisms (SNPs) that lead to amino acid substitutions in the translated proteins were found. We hypothesize that the atpA gene is involved in regulating the development of CMS.