Abstract
Background
Abnormal programmed cell death in the tapetum is induced by reactive oxygen species (ROS), which are the main factors leading to cytoplasmic male sterility (CMS). These abnormalities are caused by genetic interactions between nuclear and cytoplasmic genes. No studies have investigated the role of chloroplast ATP synthase in ROS metabolism.
Results
To explore the role of chloroplast genes in ROS metabolism, sequencing of the chloroplast genome from the next generation and single-molecule real-time sequencing of chloroplast DNA from the CMS line Jin A were performed. The results showed that the length of the chloroplast genome of the CMS line Jin A was 160,042 bp, and the genome consisted of 131 genes, including 112 functional genes. Analysis of the functional annotation and sequence comparison showed that Jin A CMS plants had 29 genes annotated with single nucleotide polymorphisms compared to Gossypium hirsutum plants, including ATP synthase subunits, NAD(P) H-quinone redox reductase subunits, and photosystem complex subunit genes. Compared to those of Jin B maintainer plants, the relative expression of atpB, atpE, and atpF significantly decreased in the anthers of Jin A CMS plants at the microspore abortion stage. The relative expression of these genes in the three-line hybrids F1 significantly increased compared with that in the Jin A CMS plants. The ROS levels in the leaves increased in the atpE and atpF silenced cotton plants.
Conclusions
In summary, our study showed that atpE and atpF of ATP synthase subunits gene were closely related to ROS metabolism. These results provide a basic information for the analysis of ATP synthase function in cotton.