The DREB7 transcription factor enhances salt tolerance in soybean plants under salt stress

DREB7 in Glycine max (L) is a novel trans-acting transcription factor (TF) that binds to the cis-acting sequences of promoters to activate the expression of downstream genes in response to abiotic factors. This study presents the experimental results and analyzes the relationship between the overexpression of the GmDREB7 and GmP5CS, as well as the proline content, in transgenic soybean lines. The results of qRT-PCR analysis of four TG1 transgenic soybean lines (TG1-2, TG1-5, TG1-7, and TG1-10) showed that the GmDREB7 gene had significantly higher transcriptional expression under untreated and salt stress conditions. Under salt stress conditions, the two transgenic lines, TG1-5 and TG1-10, had the most significant increase in GmDREB7 and GmP5CS gene expression levels, as well as the highest proline accumulation (P < 0.05). The in silico molecular docking analysis confirmed a specific interaction between the DREB7 protein and GmP5CS promoter. These findings demonstrate that overexpression of the gene encoding the TF DREB7 enhanced the transcription of the GmP5CS gene and increased proline accumulation in soybean plants under salt stress conditions. The GmDREB7 gene can be a promising candidate for enhancing salt tolerance in soybeans.