Genome-Wide Identification and Expression Analysis of the Melon ALDH Gene Family in Response to Abiotic and Biotic Stresses

Through the integration of genomic information, transcriptome sequencing data, and bioinformatics methods, we conducted a comprehensive identification of the ALDH gene family in melon. We explored the impact of this gene family on melon growth, development, and their expression patterns in various tissues and under different stress conditions. Our study discovered a total of 17 ALDH genes spread across chromosomes 1, 2, 3, 4, 5, 7, 8, 11, and 12 in the melon genome. Through a phylogenetic analysis, these genes were classified into 10 distinct subfamilies. Notably, genes within the same subfamily exhibited consistent gene structures and conserved motifs. Our study discovered a pair of fragment repeats within the melon ALDH gene. Furthermore, there was a noticeable collinearity relationship between the melon's ALDH gene and that of Arabidopsis (12 times), and rice (3 times). Transcriptome data reanalysis revealed that some ALDH genes consistently expressed highly across all tissues and developmental stages, while others were tissue or stage-specific. We analysed the ALDH gene's expression patterns under six stress types, namely salt, chilling, waterlogged, powdery mildew, fusarium wilt, and gummy stem blight. The results showed differential expression of MELO3C024328 and MELO3C004430 under all stress conditions, signifying their crucial roles in melon growth and stress response. RT-qPCR analysis further corroborated these findings. This study paves the way for future genetic improvements in melon molecular breeding.