Mulero-Aparicio Antonio, Cernava Tomislav, Turrà David, Schaefer Angelika, Di Pietro Antonio, López-Escudero Francisco Javier, Trapero Antonio, Berg Gabriele
Grupo de Patología Agroforestal, Escuela Técnica Superior de Ingenieros Agrónomos y de Montes, Departamento de Agronomía, Universidad de Córdoba, Córdoba, Spain.
Institute of Environmental Biotechnology, Graz University of Technology, Graz, Austria.
Front Microbiol. 2019 Aug 2;10:1808. doi: 10.3389/fmicb.2019.01808. eCollection 2019.
Verticillium wilts caused by spp. are among the most challenging plant diseases to control and affect numerous hosts worldwide. Due to the lack of effective, conventional control methods, integrated control strategies provide a promising approach to manage these diseases. The non-pathogenic strain FO12 was reported in previous studies to be an effective biocontrol agent against , however, its mode of action remains to be elucidated. In this study, complementary and experiments were conducted in order to explore the implications of inhibitory substances and rhizosphere competence in antagonistic effects of FO12 against and . Volatile organic compounds and soluble substances produced by FO12, which caused significant inhibition of mycelial growth and microsclerotia viability in the two tested species, were identified by means of gas and liquid chromatography-mass spectrometry. We showed that the antagonistic effect of FO12 is partially due to the production of bioactive compounds such as 3-methyl-1-butanol and 2-methyl-1-butanol, among others. Several metabolic pathways of FO12 were altered upon contact with ELV22 volatiles. The reduced production of alpha, alpha-trehalose, a metabolite used in starch and sucrose metabolism, suggests that the biocontrol agent activates its stress response in the presence of the phytopathogen. Microscopic analysis using sGFP-tagged FO12 on oil seed rape as a model plant suggests that the biocontrol strain is an efficient root colonizer, which could compete with in the same ecological niche. The findings obtained in this study provide new insights into the mode of action of this potential biocontrol agent, which are relevant for controlling Verticillium wilt through an ecologically friendly approach.
由轮枝菌属物种引起的黄萎病是最难控制的植物病害之一，在全球范围内影响众多寄主。由于缺乏有效的传统防治方法，综合防治策略为管理这些病害提供了一种有前景的途径。先前的研究报道非致病的轮枝菌菌株FO12是一种有效的防治黄萎病的生防菌，然而，其作用模式仍有待阐明。在本研究中，进行了互补的转录组和代谢组实验，以探究抑制性物质和根际定殖能力在FO12对两种轮枝菌的拮抗作用中的影响。通过气相色谱-质谱联用和液相色谱-质谱联用鉴定了FO12产生的挥发性有机化合物和可溶性物质，这些物质对两种受试轮枝菌物种的菌丝生长和微菌核活力有显著抑制作用。我们表明，FO12的拮抗作用部分归因于生物活性化合物如3-甲基-1-丁醇和2-甲基-1-丁醇等的产生。与ELV22挥发性物质接触后，FO12的几种代谢途径发生了改变。淀粉和蔗糖代谢中使用的代谢物α,α-海藻糖产量的降低表明，在植物病原菌存在的情况下，生防菌激活了其应激反应。以油菜为模式植物，使用带有绿色荧光蛋白标签的FO12进行显微镜分析表明，生防菌株是一种有效的根际定殖菌，它可以在同一生态位与轮枝菌竞争。本研究获得的结果为这种潜在生防菌的作用模式提供了新的见解，这对于通过生态友好的方法控制黄萎病具有重要意义。
