Magnaporthe oryzae is a major hazard to the growth and yield of rice and other graminaceous crops. The rice endophyte Streptomyces hygroscopicus OsiSh-2 has been reported to have a strong antagonistic effect on M. oryzae. However, the defence mechanism of OsiSh-2 against pathogens remains to be established. In this study, a combination of physiological, biochemical and label-free proteomics analyses were used to investigate the global response of OsiSh-2 to the toxins of M. oryzae (Mo-toxins). When exposed to Mo-toxins, OsiSh-2 regulated its growth rate to get rapid transition to the stationary growth phase where stronger antibiotic activity was achieved. Additionally, OsiSh-2 triggered reactive oxygen species (ROS) generation, hydrolase activity and biofilm formation in response to Mo-toxin stress. Finally, proteomic profiling confirmed that OsiSh-2 possesses the following sophisticated coping strategies against Mo-toxins: (1) sensing and transmittance of Mo-toxin signals by signal-transmitting proteins; (2) damaging the toxicity of M. oryzae by hydrolytic enzymes and other secondary products; and (3) guaranteeing the secretion and function of proteins by proteases and protein isomerases. Our research may promote the understanding of the interaction between antagonistic microbes and further broaden the scope of utilizing endophytic Streptomyces for biological control.

稻瘟病菌（Magnaporthe oryzae）对水稻和其他禾本科作物的生长和产量具有重大危害。据报道，水稻内生菌吸水链霉菌OsiSh-2对米曲霉有很强的拮抗作用。但是，OsiSh-2对病原体的防御机制仍有待建立。在这项研究中，结合了生理，生化和无标记蛋白质组学分析来研究OsiSh-2对米曲霉毒素的整体反应（运动毒素）。当暴露于Mo毒素时，OsiSh-2调节其生长速率，以快速过渡到稳定的生长期，从而获得更强的抗生素活性。此外，OsiSh-2响应Mo毒素胁迫触发了活性氧（ROS）的产生，水解酶活性和生物膜形成。最后，蛋白质组学分析证实了OsiSh-2具有以下针对Mo毒素的复杂应对策略：（1）通过信号传递蛋白感知和传递Mo毒素信号；（2）破坏米曲霉的毒性通过水解酶和其他次级产品；（3）通过蛋白酶和蛋白质异构酶保证蛋白质的分泌和功能。我们的研究可能会增进对拮抗微生物之间相互作用的理解，并进一步拓宽利用内生链霉菌进行生物学控制的范围。