Objective  Auxin is an essential plant hormone, and AUX/IAA is an important auxin initial response factor that plays a crucial role in the growth and development of plants under environmental stress. To understand the biological function of VaIAAs in the growth and development of Vigna angularis, genome-wide of VaIAAs gene family was identified and analyzed.

Method  Bioinformatics was used to identify and analyze genome-wide of AUX/IAA in Vigna angularis. Expression patterns of VaAUX/IAA gene family in various tissues were analyzed based on RNA-seq.

Result  A total of 41 VaIAAs genes were identified in genome-wide of V. angularis, and subcellular localization showed that all of them were localized to the nucleus. Phylogenetic analysis revealed that AUX/IAA proteins from V. angularis, Arabidopsis thaliana, and Oryza sativa clustered into six groups. Gene structure analysis showed that all the genes contained 1-8 introns and VaAUX/IAA genes contained 1-21 exons. Analysis of cis-acting elements found that cis-acting elements involved in response to biological/abiotic stress were the most, including the most commonly recognized ATTATA.bos, G-box and sp1 motifs. The enrichment of anaerobic-induced response element ARE and plant stress resistance-related MYB elements was also found. Protein-protein interaction network analysis showed that all VaIAAs were linked to ARF, in addition, some genes interacting with AXR3 (auxin-induced repressor), MP (transcription factor B3 family protein), and etc. VaIAAs were tissue-specific, with large differences in gene expression levels in different tissues.

Conclusion  The results of bioinformatics analysis of gene structure, phylogeny, and protein-protein network interactions of the V. angularis AUX/IAA gene family will provide important clues to reveal the functions of AUX/IAA gene family in the growth and development of V. angularis.