Genome-wide identification and expression analysis of the β-amylase genes strongly associated with fruit development, ripening, and abiotic stress response in two banana cultivars

Abstract

β-amylase (BAM) is an important enzyme involved in conversion of starch to maltose in multiple biological processes in plants. However, there is currently insufficient information on the BAM gene family in the important fruit crop banana. This study identified 16 BAM genes in the banana genome. Phylogenetic analysis showed that MaBAMs were classified into four subfamilies. Most MaBAMs in each subfamily shared similar gene structures. Conserved motif analysis showed that all identified MaBAM proteins had the typical glyco hydro 14 domains. Comprehensive transcriptomic analysis of two banana genotypes revealed the expression patterns of MaBAMs in different tissues, at various stages of fruit development and ripening, and in responses to abiotic stresses. Most MaBAMs showed strong transcript accumulation changes during fruit development and late-stage ripening. Some MaBAMs showed significant changes under cold, salt, and osmotic stresses. This finding indicated that MaBAMs might be involved in regulating fruit development, ripening, and responses to abiotic stress. Analysis of five hormone-related and seven stress-relevant elements in the promoters of MaBAMs further revealed that BAMs participated in various biological processes. This systemic analysis provides new insights into the transcriptional characteristics of the BAM genes in banana and may serve as a basis for further functional studies of such genes.

Keywords

• β-amylase|banana|genome-wide identification|fruit development|abiotic stress