State Key Lab of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Jinan, China.
FEMS Microbiol Lett. 2010 Dec;313(2):120-6. doi: 10.1111/j.1574-6968.2010.02135.x. Epub 2010 Nov 9.
Trichoderma spp. are well-known biocontrol agents because of their antimicrobial activity against bacterial and fungal phytopathogens. However, the biochemical mechanism of their antiviral activity remains largely unknown. In this study, we found that Trichokonins, antimicrobial peptaibols isolated from Trichoderma pseudokoningii SMF2, could induce defense responses and systemic resistance in tobacco (Nicotiana tabacum var. Samsun NN) against tobacco mosaic virus (TMV) infection. Local Trichokonin (100 nM) treatment led to 54% lesion inhibition, 57% reduction in average lesion diameter and 30% reduction in average lesion area in systemic tissue of tobacco compared with control, indicating that Trichokonins induced resistance in tobacco against TMV infection. Trichokonin treatment increased the production of reactive oxygen species and phenolic compounds in tobacco. Additionally, application of Trichokonins significantly increased activities of pathogenesis-related enzymes PAL and POD, and upregulated the expression of several plant defense genes. These results suggested that multiple defense pathways in tobacco were involved in Trichokonin-mediated TMV resistance. We report on the antivirus mechanism of peptaibols, which sheds light on the potential of peptaibols in plant viral disease control.
木霉属真菌是众所周知的生物防治剂，因为它们对细菌和真菌植物病原体具有抗菌活性。然而，其抗病毒活性的生化机制在很大程度上尚不清楚。在本研究中，我们发现从哈茨木霉 SMF2 中分离得到的抗菌肽类化合物曲古抑菌素能够诱导烟草（Nicotiana tabacum var. Samsun NN）对烟草花叶病毒（TMV）感染产生防御反应和系统抗性。局部施用 100 nM 的曲古抑菌素可使烟草局部组织的病斑抑制率达到 54%，平均病斑直径减少 57%，平均病斑面积减少 30%，表明曲古抑菌素诱导了烟草对 TMV 感染的抗性。曲古抑菌素处理增加了烟草中活性氧和酚类化合物的产生。此外，曲古抑菌素的应用显著增加了病程相关酶 PAL 和 POD 的活性，并上调了几种植物防御基因的表达。这些结果表明，烟草中的多种防御途径参与了曲古抑菌素介导的 TMV 抗性。我们报告了肽类化合物的抗病毒机制，这为肽类化合物在植物病毒病防治中的应用提供了新的思路。
