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.

中文翻译：

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iTRAQ在高温胁迫下大豆花药的差异蛋白质组学分析。

高温严重影响大豆雄性生殖器官的功能和发育。但是，大豆中耐热分子机制尚不清楚。在这项研究中，使用基于iTRAQ的方法在耐热（JD21）和热敏（HD14）品种的花药之间进行了差异蛋白质组分析。在自然田间条件下，经高温胁迫处理的HD14花药与HD14花药相比，在高温胁迫下处理的JD21花药与在JD21花药中处理的JD21花药之间，总共鉴定出371、479和417个差异丰富的蛋白质。 HD14和JD21花药分别用高温胁迫处理。与耐热性相关的差异丰富的蛋白质主要参与碳水化合物和能量代谢，蛋白质合成和降解，氮同化和ROS解毒。在与热量相关的三个比较中，十六种常见的差异丰富的蛋白质参与了已知的蛋白质-蛋白质相互作用网络，这可能强烈影响花药的生长和发育。qRT-PCR分析验证了iTRAQ结果的可靠性。总之，通过调节HSP家族蛋白，果胶酯酶，脯氨酸蛋白，S-腺苷甲硫氨酸合酶，过氧化物酶，GST，肽基脯氨酰异构酶和二硫键异构酶，耐热品种在胁迫下的表现优于热敏品种。

意义

近年来，由于气候变化带来的高温（HT）压力经常在花期发生，并负面影响大豆的生产力。大豆花药对HT反应的潜在分子机制是一个相对复杂的过程，因此难以阐明。然而，有可能在HT胁迫下鉴定热敏和耐热品种之间差异表达的基因或蛋白质。然后可以利用潜在的候选基因或蛋白质阐明大豆对HT胁迫响应的分子机制，并为改善大豆的耐热特性提供遗传资源。在目前的研究中，使用基于iTRAQ的蛋白质组学策略，比较了HT胁迫下耐热（JD21）和热敏（HD14）品种在花药中发生的定量和定性蛋白质组变化。我们的结果提供了对HT胁迫下对HT抗性和HT敏感的大豆品种的翻译变化的新见解，这有助于解决大豆对HT胁迫的潜在分子机制。