Ongena Marc, Jacques Philippe, Touré Yacine, Destain Jacqueline, Jabrane Abdelhamid, Thonart Philippe
Centre Wallon de Biologie Industrielle, Université de Liège, Boulevard du Rectorat 29, Bâtiment B40, Liège 4000, Belgium.
Appl Microbiol Biotechnol. 2005 Nov;69(1):29-38. doi: 10.1007/s00253-005-1940-3. Epub 2005 Oct 20.
In this work, the potential of Bacillus subtilis strain M4 at protecting plants against fungal diseases was demonstrated in different pathosystems. We provide evidence for the role of secreted lipopeptides, and more particularly of fengycins, in the protective effect afforded by the strain against damping-off of bean seedlings caused by Pythium ultimum and against gray mold of apple in post-harvest disease. This role was demonstrated by the strong biocontrol activity of lipopeptide-enriched extracts and through the detection of inhibitory quantities of fengycins in infected tissues. Beside such a direct antagonism of the pathogen, we show that root pre-inoculation with M4 enabled the host plant to react more efficiently to subsequent pathogen infection on leaves. Fengycins could also be involved in this systemic resistance-eliciting effect of strain M4, as these molecules may induce the synthesis of plant phenolics involved in or derived from the defense-related phenylpropanoid metabolism. Much remains to be discovered about the mechanisms by which Bacillus spp suppress disease. Through this study on strain M4, we reinforce the interest in B. subtilis as a pathogen antagonist and plant defense-inducing agent. The secretion of cyclic fengycin-type lipopeptides may be tightly related to the expression of these two biocontrol traits.
在本研究中，枯草芽孢杆菌M4菌株在不同病害体系中展现出了保护植物免受真菌病害侵害的潜力。我们提供了证据，证明分泌型脂肽，尤其是丰原素，在该菌株对由终极腐霉引起的菜豆幼苗猝倒病以及采后苹果灰霉病的防治效果中发挥了作用。富含脂肽的提取物具有强大的生防活性，且在受感染组织中检测到了抑制量的丰原素，从而证明了这一作用。除了对病原体的直接拮抗作用外，我们还表明，用M4菌株对根部进行预接种能使宿主植物对随后叶片上的病原体感染做出更有效的反应。丰原素也可能参与了M4菌株的这种诱导系统抗性的效应，因为这些分子可能会诱导参与防御相关苯丙烷代谢或由其衍生而来的植物酚类物质的合成。关于芽孢杆菌属抑制病害的机制，仍有许多有待发现。通过对M4菌株的这项研究，我们进一步强调了枯草芽孢杆菌作为病原体拮抗剂和植物防御诱导剂的重要性。环状丰原素型脂肽的分泌可能与这两种生防特性的表达密切相关。
