PDF(Pubmed)
Abstract：
Fusarium oxysporum f. sp. cubense (Foc) tropical race 4 (TR4) is threatening banana production because of its increasing spread. Biological control approaches have been widely studied and constitute interesting complementary measures to integrated disease management strategies. They have been based mainly on the use of single biological control agents (BCAs). In this study, we moved a step forward by designing a synthetic microbial community (SynCom) for the control of Fusarium wilt of banana (FWB). Ninety-six isolates of Pseudomonas spp., Bacillus spp., Streptomyces spp., and Trichoderma spp. were obtained from the banana rhizosphere and selected in vitro for the antagonism against Foc TR4. In pot experiments, a large community such as SynCom 1.0 (44 isolates with moderate to high antagonistic activity) or a small one such as SynCom 1.1 (seven highly effective isolates) provided similar disease control (35% symptom severity reduction). An in vitro study of the interactions among SynCom 1.1 isolates and between them and Foc revealed that beneficial microorganisms not only antagonized the pathogen but also some of the SynCom constituents. Furthermore, Foc defended itself by antagonizing the beneficial microbes. We also demonstrated that fusaric acid, known as one of the secondary metabolites of Fusarium species, might be involved in such an interaction. With this knowledge, SynCom 1.2 was then designed with three isolates: Pseudomonas chlororaphis subsp. piscium PS5, Bacillus velezensis BN8.2, and Trichoderma virens T2C1.4. A non-simultaneous soil application of these isolates (to diminish cross-inhibition) delayed FWB progress over time, with significant reductions in incidence and severity. SynCom 1.2 also performed better than two commercial BCAs, BioPak® and T-Gro. Eventually, SynCom 1.2 isolates were characterized for several biocontrol traits and their genome was sequenced. Our data showed that assembling a SynCom for biocontrol is not an easy task. The mere mixtures of antagonists (e.g., SynCom 1.0 and 1.1) might provide effective biocontrol, but an accurate investigation of the interactions among beneficial microorganisms is needed to improve the results (e.g., SynCom 1.2). SynCom 1.2 is a valuable tool to be further developed for the biological control of FWB.
摘要：
尖孢镰刀菌f.sp.cubense（Foc）热带种族4（TR4）由于其传播的增加而威胁着香蕉的生产。生物控制方法已得到广泛研究，并构成了综合疾病管理策略的有趣补充措施。它们主要基于单一生物防治剂(BCA)的使用。在这项研究中,我们通过设计合成微生物群落（SynCom）来控制香蕉枯萎病（FWB）向前迈出了一步。假单胞菌属的96个分离株。,芽孢杆菌。,链霉菌属。,和木霉属。从香蕉根际获得，并在体外选择对FocTR4的拮抗作用。在盆栽实验中,SynCom1.0(44个具有中等至高拮抗活性的分离株)等大型群体或SynCom1.1(7个高效分离株)等小型群体提供了相似的疾病控制(症状严重程度降低35%).对SynCom1.1分离株之间以及它们与Foc之间的相互作用的体外研究表明，有益微生物不仅拮抗病原体，而且还拮抗某些SynCom成分。此外，Foc通过对抗有益的微生物来捍卫自己。我们还证明了，镰刀酸，镰刀菌属的次生代谢产物之一,可能参与了这样的互动。有了这些知识,然后用三种分离物设计了SynCom1.2：绿鱼假单胞菌亚种。pisciumPS5、BBN8.2和绿木霉T2C1.4。这些分离物的非同时土壤施用（以减少交叉抑制）会随着时间的推移延迟FWB进展，发病率和严重程度显着降低。SynCom1.2的表现也优于两个商业BCA，BioPak®和T-Gro。最终,对SynCom1.2分离株的几种生物控制性状进行了表征，并对其基因组进行了测序。我们的数据表明，组装用于生物防治的SynCom并非易事。仅仅是拮抗剂的混合物(例如，SynCom1.0和1.1)可能提供有效的生物控制，但需要对有益微生物之间的相互作用进行准确的调查以改善结果(例如，SynCom1.2)。SynCom1.2是进一步开发用于FWB生物控制的有价值的工具。
