关键词: 香蕉, Aux/IAA基因家族, 生物信息学, 基因表达

Abstract: In this study，the banana Aux/IAA gene family members were screened and identified from genome level using bioinformatic methods. A total of 44 Aux/IAA family members distributed in all the banana chromosomes except chromosome 1 were identified，among which 10 members own alternative splicing variants. The coding sequence of these genes ranges from 378 to 1 062 bp，encoding proteins with 125–353 aa. All of their encoded protein were hydrophilic proteins without signal peptide. Gene structure analysis showed that most members of the family shared 5 exons and 4 introns，and most of their encoded proteins contained 4 typical conserved motifs. Subcellular location prediction results showed that the Aux/IAA members were mainly located in nucleus，cytoplasm and chloroplast. MaIAA31 is the only member of the family that predicted a transmembrane region and was located outside the extracellular. Phylogenetic tree analysis revealed that the family members could be divided into two major categories and eight subgroups. Promoter cis-acting elements prediction analysis identified several elements responsive to phytohormone and light，abiotic and biotic stresses. Gene expression analysis of several Aux/IAA members under different phytohormone and stress treatments revealed that the expression of Aux/IAAs were regulated by multiple factors. Among these investigated genes，the expression of MaIAA27 was found to be responsive to all the treatments，MaIAA15 was influenced by drought and salt，while MaIAA25 was greatly induced by heat，low-temperature and wound，indicating that they might contribute to the stress responses of banana.

Key words: banana, Aux/IAA gene family, bioinformatic analysis, gene expression