Identification and characterization of the mango eIF gene family reveals MieIF1A-a, which confers tolerance to salt stress in transgenic Arabidopsis

Eukaryotic translation initiation factors (eIFs) function as important regulatory factors in protein synthesis and play crucial roles in the response to abiotic stress in plants. However, the eIF gene family and its biological functions have not been studied in mango (Mangifera indica L.). In this study, 18 eIF genes were identified from mango transcriptome data and subjected to phylogenetic analysis, which indicated that the 67 eIF proteins from mango, Arabidopsis, Oryza sativa, and Citrus clementina clustered into three major groups. Quantitative reverse transcription PCR analysis demonstrated that the expression of most of the 18 MielF genes were closely associated with abiotic stress, and MieIF1A-a, MieIF5, and MieIF3sB were most strongly expressed under salinity, osmotic, and low temperature (2 degrees C) stress, respectively. Transgenic analysis indicated that the overexpression of MielF1A-a in Arabidopsis resulted in enhanced seedling growth and survival rates, higher chlorophyll content, increased superoxide dismutase, peroxidase, and catalase activities, and decreased malondialdehyde accumulation under salt treatment compared to the wild-type Arabidopsis. Our findings revealed that MielF genes are associated with abiotic stress in mango, and MieIF1A-a can enhance the salt tolerance of transgenic Arabidopsis through increasing antioxidant enzyme activities. This study provides new insights into the MielF genes that could be applied to the breeding of stress-resistant mango varieties.