Identification of DREB Family Genes in Banana and Their Function under Drought and Cold Stress

Abstract

Bananas are one of the most important cash crops in the tropics and subtropics. Drought and low-temperature stress affect the growth of banana. The DREB (dehydration responsive element binding protein) gene family, as one of the major transcription factor families, plays crucial roles in defense against abiotic stress. Currently, systematic analyses of the banana DREB (MaDREB) gene family have not yet been reported. In this study, 103 members of the MaDREB gene family were identified in the banana genome. In addition, transcriptomic analysis results revealed that MaDREBs responded to drought and cold stress. The expression of MaDREB14/22/51 was induced by drought and cold stress; these geneswere selected for further analysis. The qRT-PCR validation results confirmed the transcriptome results. Additionally, transgenic Arabidopsis plants overexpressing MaDREB14/22/51 exhibited enhanced resistance to drought and cold stress by reducing MDA content and increasing PRO and soluble sugar content. This study enhances our understanding of the function of the MaDREB gene family, provides new insights into their regulatory role under abiotic stress, and lays a good foundation for improving drought and cold stress-tolerant banana verities.

Keywords: DREB; climate change; cold; drought; genome-wide.

Figure 1

Construction of a tree of the banana DREB gene family. The tree illustrates the relationships within the DREB family across banana and Arabidopsis thaliana.

Figure 2

Analysis of DREB gene family domain in banana. The motifs are depicted through the use of three distinct color-coded boxes. A schematic representation of the UTR, exon, and intron regions, where green frames denote the UTR, exons are symbolized by yellow boxes, introns are signified by black lines, providing a clear visualization of the gene structures.

Figure 3

The promoter element analysis. The distribution and density of cis-acting elements within the upstream promoter region of MaDREBs are shown.

Figure 4

The collinearity distribution of MaDREBs. (A) Synteny collinearity of banana, Arabidopsis and rice genomes (B). The blue line represents the associated gene pairs; in this map, blue lines denote homologous associations between the two species.

Figure 5

The predicted interaction networks of MaDREB proteins. This visualization provides insights into the potential functional associations and networks that MaDREB genes may be a part of within the cellular context.

Figure 6

Transcriptome analysis of MaDREBs responding to drought and cold stress (A) and qRT-PCR of MaDREBs responding to drought and cold stress (B). Red and blue indicated high and low expression levels, respectively. The a–c was marked on top of the blank bar, which represented differential significance.

Figure 7

Phenotypes of transgenic Arabidopsis under drought and cold stress treatments and chlorophyll fluorescence measurements. (A) MaDREB14, (B) MaDREB22, (C) MaDREB51.

Figure 8

Detection of relative expression of MaDREB14/22/51 in transgenic Arabidopsis thaliana under drought and cold stress. Data are means ± SD of n = 3 biological replicates. Means denoted by the same letter are not significantly different at p < 0.05 as determined by Duncan’s multiple range test.

Figure 9

Measurement of physiological indicators in transgenic Arabidopsis thaliana ((A) MaDREB14; (B) MaDREB22; (C) MaDREB51) under drought and cold stress. Data are means ± SD of n = 3 biological replicates. Means denoted by the same letter are not significantly different at p < 0.05 as determined by Duncan’s multiple range test.