Genome-Wide Identification, Evolutionary Analysis, and Functional Studies of APX Genes in Melon ( Cucuis melo L.)

• Published in: International journal of molecular sciences Vol. 24; no. 24; p. 17571
• Main Authors: Song, Jiayan, Zhu, Zicheng, Zhang, Taifeng, Meng, Xiaobing, Zhang, Wencheng, Gao, Peng
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 17-12-2023
• Subjects: Abiotic stress; APX gene family; Chromosomes; Flowers & plants; functional validation; Genes; Genomes; Homeostasis; Localization; melon; Phylogenetics; Proteins; Salinity; Salt; salt stress; salt stress; functional validation; melon; APX gene family
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms242417571

The antioxidative enzyme ascorbate peroxidase (APX) exerts a critically important function through scavenging reactive oxygen species (ROS), alleviating oxidative damage in plants, and enhancing their tolerance to salinity. Here, we identified 28
genes that display an uneven distribution pattern throughout the 12 chromosomes of the melon genome by carrying out a bioinformatics analysis. Phylogenetic analyses revealed that the
gene family comprised seven different clades, with each clade of genes exhibiting comparable motifs and structures. We cloned 28
genes to infer their encoded protein sequences; we then compared these sequences with proteins encoded by rice APX proteins (OsAPX2),
APX proteins (PutAPX) and with pea APX proteins. We found that the
,
, and
genes in Clade I were closely related, and their structures were highly conserved.
(
) was found to promote resistance to 150 mM NaCl salt stress, according to quantitative real-time fluorescence PCR. Transcriptome data revealed that
was differentially expressed among tissues, and the observed differences in expression were significant. Virus-induced gene silencing of
significantly decreased salinity tolerance, and
exhibited differential expression in the leaf, stem, and root tissues of melon plants. This finding demonstrates that
exerts a key function in melon's tolerance to salt stress. Generally,
could be a target in molecular breeding efforts aimed at improving the salt tolerance of melon; further studies of
could unveil novel physiological mechanisms through which antioxidant enzymes mitigate the deleterious effects of ROS stress.