Genome-wide characterisation of superoxide dismutase genes in grape and their expression analyses during berry development process

Previous studies about superoxide dismutase (SOD) genes were mostly with regard to biotic and abiotic stress responses. Some reports have indicated SOD genes may play an important role in plant development. However, little is known about the relationship of SOD genes with grape berry ripening. Thirteen VviSOD genes were identified from grape genome sequences based on the bioinformatic method. Phylogenetic analysis indicated that these VviSODs could be divided into two groups. The genes of VviCu/ZnSOD1a and VviCu/ZnSOD1c were identified as tandem replication genes. The expression analyses based on RNA-Seq and qRT-PCR results in ‘Kyoho’ and its early-ripening bud mutant, ‘Fengzao’, demonstrated that the VviSOD genes involved in the grape berry ripening and VviCu/ZnSOD1c were the main candidate. Sequence analysis of VviCu/ZnSOD1c gene in ‘Fengzao’ showed that the coding sequence was the same as that of ‘Kyoho’. According to the bioinformatic and expression analysis, VviSOD genes probably involved in the grape berry ripening and VviCu/ZnSOD1c was selected as the main candidate to further explore its potential role in the early ripening of ‘Fengzao’.