Differential proteomic analysis of soybean anthers by iTRAQ under high-temperature stress

Abstract

High-temperature has severe impacts on the functionality and development of soybean male reproductive organs. However, the molecular mechanism of thermo-tolerance in soybean remains unclear. In this study, a differential proteomic analysis was conducted between the anthers of heat-tolerant (JD21) and heat-sensitive (HD14) cultivars using an iTRAQ based approach. In total, 371, 479, and 417 differentially abundant proteins were identified between HD14 anthers treated with high-temperature stress vs HD14 anthers in the natural field conditions, JD21 anthers treated with high-temperature stress vs JD21 anthers in the natural field conditions, and HD14 vs JD21 anthers treated with high-temperature stress, respectively. The differentially abundant proteins associated with thermo-tolerance were predominantly involved in carbohydrate and energy metabolism, protein synthesis and degradation, nitrogen assimilation, and ROS detoxification. Sixteen common differentially abundant proteins were involved in known protein-protein interaction networks in three comparisons associated with heat, which may strongly influence anther growth and development. The qRT-PCR analysis validated the reliability of the iTRAQ results. In conclusion, the heat-tolerant cultivar performed better under stress than heat-sensitive cultivar through modulation of HSP family proteins, pectinesterase, profilin, S-adenosylmethionine synthase, peroxidase, GST, peptidylprolyl isomerase, and disulfide-isomerase. The results provide novel insight into the mechanism of high-temperature stress response of soybean. SIGNIFICANCE: In recent years, with the high temperature (HT) stress brought by climate change frequently occurs at anthesis and negatively affects soybean productivity. The molecular mechanism underlying the response of soybean anthers to HT is a relatively complex process and thus difficult to elucidate; however, it is possible to identify differentially expressed genes or proteins between heat-sensitive and heat-tolerant cultivars under HT stress. The potential candidate genes or proteins may then be utilized in elucidating the molecular mechanism underlying the response of soybean to HT stress, as well as provide genetic resource for the improvement of heat-tolerant characteristics in soybean. In present study, quantitative and qualitative proteomic changes occurring in anthers were compared between the heat-tolerant (JD21) and heat-sensitive (HD14) cultivars under HT stress using iTRAQ-based proteomics strategy. Our results provide new insight into translational alterations in HT-resistant and HT-sensitive soybean cultivars under HT stress, which helps to address the underlying molecular mechanism of soybean in response to HT stress.

Keywords: Differentially abundant proteins (DAPs); High-temperature (HT) stress; Molecular mechanism; Proteomics; Soybean.