Genome-wide identification and comprehensive analysis of annexin encoding genes in Vigna mungo (L.) Hepper

Vigna mungo (L.) Hepper, commonly called as black gram is one of the major pulse crop belongs to fabaceae family. Plant annexins are a well-known protein family involved in crucial biological processes such as membrane binding, calcium signalling, and stress responses through Ca2+ transport. In rice and Arabidopsis, annexins have been already identified and characterized. But information about annexins in Vigna mungo is limited. Based on the availability of the Vigna mungo genome sequence, we have identified eleven annexin gene members and performed the comprehensive analysis. Four conserved domains were found in all members except VmAnn10 and VmAnn11, which contained three domains in each. The motifs analysis showed the presence of 20 motifs in eleven VmAnn protein sequences. Gene structure analysis showed the presence of 3–5 introns in VmAnn gene members. Chromosomal distribution suggested that VmAnn genes might have undergone gene expansion through both segmental and tandem duplication events. For both paralogous and orthologous genes, the Ka/Ks ratios were found to be less than 1, suggesting that VmAnn genes have experienced purifying selection. Based on phylogenetic analysis of VmAnn proteins with OsAnn and AtAnn, all the members were clustered into six groups and shared a close evolutionary relationship. Moreover, the upstream promoter sequence analysis showed the presence of core cis-elements such as; TATA box, CAAT box and others elements related to growth and development, phytohormones and abiotic stress. It indicates the regulatory role of annexins in Vigna mungo in different processes. These results provide important information for further research on VmAnn genes and their characterization.