Consortia of anti-nematode fungi and bacteria in the rhizosphere of soybean plants attacked by root-knot nematodes

• Main Authors: Hirokazu Toju, Yu Tanaka
• Format: Article
• Language: English
• Published: The Royal Society 2019-03-01
• Series: Royal Society Open Science
• Subjects: disease-suppressive soil; glycine max; meloidogyne; nematophagous fungi; phytopathogenic pathogens and pests; sustainable agriculture
• Online Access: https://royalsocietypublishing.org/doi/pdf/10.1098/rsos.181693

Cyst and root-knot nematodes are major risk factors of agroecosystem management, often causing devastating impacts on crop production. The use of microbes that parasitize or prey on nematodes has been considered as a promising approach for suppressing phytopathogenic nematode populations. However, effects and persistence of those biological control agents often vary substantially depending on regions, soil characteristics and agricultural practices: more insights into microbial community processes are required to develop reproducible control of nematode populations. By performing high-throughput sequencing profiling of bacteria and fungi, we examined how root and soil microbiomes differ between benign and nematode-infected plant individuals in a soybean field in Japan. Results indicated that various taxonomic groups of bacteria and fungi occurred preferentially on the soybean individuals infected by root-knot nematodes or those uninfected by nematodes. Based on a network analysis of potential microbe–microbe associations, we further found that several fungal taxa potentially preying on nematodes (Dactylellina (Orbiliales), Rhizophydium (Rhizophydiales), Clonostachys (Hypocreales), Pochonia (Hypocreales) and Purpureocillium (Hypocreales)) co-occurred in the soybean rhizosphere at a small spatial scale. This study suggests how ‘consortia’ of anti-nematode microbes can derive from indigenous (resident) microbiomes, providing basic information for managing anti-nematode microbial communities in agroecosystems.