Physiological and molecular mechanisms of leaf response to high-temperature stress in high-temperature-resistant soybean varieties

BackgroundWith increasing global limate warm, high temperature (HT) is one of limiting factors for soybean yield and quality. Exploring HT resistance-related functional genes and their corresponding molecular mechanisms is of great value. In our previous report, compared with HD14 (HT sensitive), JD21 is an HT-resistant variety, and further analysis of the transcriptome and proteome has revealed the HT tolerance mechanism of JD21 anthers. We found that compared with those of HD14 (28.72%), the leaves of JD21 also exhibited HT resistance, and the degree of leaf wilting in JD21 plants after HT stress treatment was 11.02%; however, the regulatory mechanism of the response of JD21 to HT stress is still unclear.ResultsIn this study, comparative transcriptome analysis of JD21 and HD14 soybean leaves after HT stress and field control plants was performed by RNA-seq analysis. The results showed that the number of upregulated differentially expressed genes (DEGs) in JD21 and HD14 was greater than the number of downregulated DEGs after HT stress, and the number of up- or down-regulated DEGs in JD21 was higher than those of HD14. Bioinformatics analysis revealed that many DEGs were involved in various molecular functions and metabolic pathways. QRT-PCR analysis verified that the gene expression pattern results determined via RNA-seq was reliable. In addition, through analysis of gene expression level and conserved domain, 18 key candidate genes related to the response of soybean leaves to HT stress were screened.ConclusionsThis study systematically revealed the regulation mechanism of soybean leaves molecular transcription level by RNA-seq, and several key candidate DEGs (transcription factor, HSPs, HSFs, GmCYP78A6, etc.) involved in the response to HT stress were identified based on the bioinformatics analysis. The results provided a theoretical basis for studying the response mechanism of soybean leaves to HT stress.