Qiu Zhiheng, Wu Xiangli, Zhang Jinxia, Huang Chenyang
Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, China.
Key Laboratory of Microbial Resources, Ministry of Agriculture, Beijing, China.
PLoS One. 2017 Oct 26;12(10):e0187055. doi: 10.1371/journal.pone.0187055. eCollection 2017.
Trichoderma asperellum is one of the species which can be isolated from contaminated Pleurotus ostreatus cultivation substrate with green mold disease. This study focused on the relationship between high temperature and infectivity of T. asperellum to P. ostreatus. Antagonism experiments between T. asperellum and P. ostreatus mycelia revealed that high temperature-treated P. ostreatus mycelia were more easily infected by T. asperellum and covered by conidia. Microscopic observation also showed that P. ostreatus mycelia treated with high temperature could adsorb more T. asperellum conidia. Furthermore, conidia obtained from T. asperellum mycelia grown at 36°C featured higher germination rate compared with that incubated at 28°C. High temperature-treated T. asperellum mycelia can produce conidia in shorter periods, and T. asperellum mycelia were less sensitive to high temperature than P. ostreatus. Deactivated P. ostreatus mycelia can induce T. asperellum cell wall-degrading enzymes (CWDEs) and P. ostreatus mycelia subjected to high temperature showed induced CWDEs more effective than those incubated at 28°C. Moreover, T. asperellum showed higher CWDEs activity at high temperature. In dual cultures, hydrogen peroxide (H2O2) increased after 36°C, and high concentration of H2O2 could significantly inhibit the growth of P. ostreatus mycelia. In summary, our findings indicated for the first time that high temperature can induce a series of mechanisms to enhance infection abilities of T. asperellum to P. ostreatus mycelia and to cause Pleurotus green mold disease.
棘孢木霉是可从患有绿霉病的污染平菇栽培基质中分离出的物种之一。本研究聚焦于高温与棘孢木霉对平菇的侵染性之间的关系。棘孢木霉与平菇菌丝体之间的拮抗实验表明，经高温处理的平菇菌丝体更容易被棘孢木霉感染并被分生孢子覆盖。显微镜观察还显示，经高温处理的平菇菌丝体能够吸附更多的棘孢木霉分生孢子。此外，与在28°C培养的分生孢子相比，从在36°C生长的棘孢木霉菌丝体获得的分生孢子具有更高的萌发率。经高温处理的棘孢木霉菌丝体能够在更短的时间内产生分生孢子，并且棘孢木霉菌丝体对高温的敏感性低于平菇。失活的平菇菌丝体能够诱导棘孢木霉细胞壁降解酶（CWDEs），并且经高温处理的平菇菌丝体比在28°C培养的菌丝体更有效地诱导产生CWDEs。此外，棘孢木霉在高温下表现出更高的CWDEs活性。在共培养中，36°C后过氧化氢（H2O2）增加，并且高浓度的H2O2能够显著抑制平菇菌丝体的生长。总之，我们的研究结果首次表明，高温能够诱导一系列机制来增强棘孢木霉对平菇菌丝体的感染能力并引发平菇绿霉病。
