Co-occurrence network analysis unveils the actual differential impact on the olive root microbiota by two Verticillium wilt biocontrol rhizobacteria

Environmental Microbiome

Research

Manuel Fernández-López¹  Antonio J. Fernández-González¹  Antonio Valverde-Corredor²  Martina Cardoni²  Jesús Mercado-Blanco³ 

[1] Departamento de Microbiología del Suelo y la Planta, Estación Experimental del Zaidín, CSIC, Granada, Spain;Departamento de Protección de Cultivos, Instituto de Agricultura Sostenible, Consejo Superior de Investigaciones Científicas [CSIC], Córdoba, Spain;Departamento de Protección de Cultivos, Instituto de Agricultura Sostenible, Consejo Superior de Investigaciones Científicas [CSIC], Córdoba, Spain;Departamento de Microbiología del Suelo y la Planta, Estación Experimental del Zaidín, CSIC, Granada, Spain;

关键词: Biological control agents;    Network topology;    Olea europaea;    Paenibacillus polymyxa;    Pseudomonas simiae;    Root microbial community;    Verticillium dahliae;   

DOI  :  10.1186/s40793-023-00480-2

 received in 2022-11-14, accepted in 2023-03-09,  发布年份 2023

来源: Springer

【 摘 要 】

BackgroundVerticillium wilt of olive (VWO), caused by Verticillium dahliae Kleb, is one of the most threatening diseases affecting olive cultivation. An integrated disease management strategy is recommended for the effective control of VWO. Within this framework, the use of biological control agents (BCAs) is a sustainable and environmentally friendly approach. No studies are available on the impact that the introduction of BCAs has on the resident microbiota of olive roots. Pseudomonas simiae PICF7 and Paenibacillus polymyxa PIC73 are two BCAs effective against VWO. We examined the effects of the introduction of these BCAs on the structure, composition and co-occurrence networks of the olive (cv. Picual) root-associated microbial communities. The consequences of the subsequent inoculation with V. dahliae on BCA-treated plants were also assessed.ResultsInoculation with any of the BCAs did not produce significant changes in the structure or the taxonomic composition of the ‘Picual’ root-associated microbiota. However, significant and distinctive alterations were observed in the topologies of the co-occurrence networks. The introduction of PIC73 provoked a diminution of positive interactions within the ‘Picual’ microbial community; instead, PICF7 inoculation increased the microbiota’s compartmentalization. Upon pathogen inoculation, the network of PIC73-treated plants decreased the number of interactions and showed a switch of keystone species, including taxa belonging to minor abundant phyla (Chloroflexi and Planctomycetes). Conversely, the inoculation of V. dahliae in PICF7-treated plants significantly increased the complexity of the network and the number of links among their modules, suggestive of a more stable network. No changes in their keystone taxa were detected.ConclusionThe absence of significant modifications on the structure and composition of the ‘Picual’ belowground microbiota due to the introduction of the tested BCAs underlines the low/null environmental impact of these rhizobacteria. These findings may have important practical consequences regarding future field applications of these BCAs. Furthermore, each BCA altered the interactions among the components of the olive belowground microbiota in idiosyncratic ways (i.e. PIC73 strongly modified the number of positive relations in the ‘Picual’ microbiota whereas PICF7 mostly affected the network stability). These modifications may provide clues on the biocontrol strategies used by these BCAs.

【 授权许可】

CC BY   
© The Author(s) 2023. corrected publication 2023

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