背景:甘蓝枯萎病(CFW)是由土壤传播的真菌尖孢镰刀菌引起的破坏性疾病。凝集素(Foc)。管理CFW的最佳措施之一是采用耐性/抗性卷心菜品种。然而,植物基因型与病原体Foc在塑造根际微生物群落中的相互作用,以及这些微生物组合对生物抗性的影响,仍然没有得到充分的理解。
结果:基于扩增子元编码数据,我们观察到YR(抗Foc)和ZG(易感Foc)白菜品种的根际内真菌α多样性指数(Shannon指数)和β多样性指数(未加权Bray-Curtis差异)的明显差异,不管Foc接种。值得注意的是,接种Foc后,抗性YR品种的Shannon多样性变化更为明显。抗病植物品种表现出更高的携带有益微生物的倾向,如假单胞菌,并在逃避有害微生物方面表现出卓越的能力,与他们易感疾病的同行相反。此外,网络分析是对根际相关微生物进行的,包括细菌和真菌。从YR恢复的关联网络表现出更大的复杂性,鲁棒性,和密度,不管Foc接种。在YR根际感染Foc后,优势细菌NA13显着增加,它也是微生物网络中的枢纽分类单元。将NA13重新引入土壤中,显著提高了易感ZG品种的抗病性,通过直接抑制Foc并在根部触发防御机制。
结论:这两个甘蓝品种的根际微生物群落明显不同,病原体的引入会导致其微生物网络发生重大变化,这与对土壤传播病原体的敏感性或抗性有关。此外,我们发现了一种根瘤菌,它能显著提高易感白菜的抗病性。我们的结果表明,抗性基因的诱导导致微生物群落对病原体的不同反应可能部分解释了测试的白菜品种对CFW的不同敏感性。视频摘要。
BACKGROUND: Cabbage Fusarium wilt (CFW) is a devastating disease caused by the soil-borne fungus Fusarium oxysporum f. sp. conglutinans (Foc). One of the optimal measures for managing CFW is the employment of tolerant/resistant
cabbage varieties. However, the interplay between plant genotypes and the pathogen Foc in shaping the rhizosphere microbial community, and the consequent influence of these microbial assemblages on biological resistance, remains inadequately understood.
RESULTS: Based on amplicon metabarcoding data, we observed distinct differences in the fungal alpha diversity index (Shannon index) and beta diversity index (unweighted Bray-Curtis dissimilarity) within the rhizosphere of the YR (resistant to Foc) and ZG (susceptible to Foc)
cabbage varieties, irrespective of Foc inoculation. Notably, the Shannon diversity shifts in the resistant YR variety were more pronounced following Foc inoculation. Disease-resistant plant variety demonstrate a higher propensity for harboring beneficial microorganisms, such as Pseudomonas, and exhibit superior capabilities in evading harmful microorganisms, in contrast to their disease-susceptible counterparts. Furthermore, the network analysis was performed on rhizosphere-associated microorganisms, including both bacteria and fungi. The networks of association recovered from YR exhibited greater complexity, robustness, and density, regardless of Foc inoculation. Following Foc infection in the YR rhizosphere, there was a notable increase in the dominant bacterium NA13, which is also a hub taxon in the microbial network. Reintroducing NA13 into the soil significantly improved disease resistance in the susceptible ZG variety, by directly inhibiting Foc and triggering defense mechanisms in the roots.
CONCLUSIONS: The rhizosphere microbial communities of these two
cabbage varieties are markedly distinct, with the introduction of the pathogen eliciting significant alterations in their microbial networks which is correlated with susceptibility or resistance to soil-borne pathogens. Furthermore, we identified a rhizobacteria species that significantly boosts disease resistance in susceptible cabbages. Our results indicated that the induction of resistance genes leading to varied responses in microbial communities to pathogens may partly explain the differing susceptibilities of the
cabbage varieties tested to CFW. Video Abstract.