title: Non-specific transient mutualism between the plant parasitic nematode, Bursaphelenchus xylophilus, and the opportunistic bacterium Serratia quinivorans BXF1, a plant-growth promoting pine endophyte with antagonistic effects.
abstract: The aim of this study is to understand the biological role of Serratia quinivorans BXF1, a bacterium commonly found associated with Bursaphelenchus xylophilus, the plant parasitic nematode responsible for pine wilt disease. Therefore, we studied strain BXF1 effect in pine wilt disease. We found that strain BXF1 promoted in vitro nematode reproduction. Moreover, the presence of bacteria led to the absence of nematode chitinase gene (Bxcht-1) expression, suggesting an effect for bacterial chitinase in nematode reproduction. Nevertheless, strain BXF1 was unable to colonize the nematode interior, bind to its cuticle with high affinity or protect the nematode from xenobiotic stress. Interestingly, strain BXF1 was able to promote tomato and pine plant-growth, as well as to colonize its interior, thus, acting like a plant-growth promoting endophyte. Consequently, strain BXF1 failed to induce wilting symptoms when inoculated in pine shoot artificial incisions. This bacterium also presented strong antagonistic activities against fungi and bacteria isolated from Pinus pinaster. Our results suggest that B. xylophilus does not possess a strict symbiotic community capable of inducing pine wilt disease symptoms as previously hypothesized. We show that bacteria like BXF1, which possess plant-growth promoting and antagonistic effects, may be opportunistically associated with B. xylophilus, possibly acquired from the bacterial endophytic community of the host pine.
authors: Nemalab/ICAAM - Instituto de Ciências Agrárias e Ambientais Mediterrânicas, Departamento de Biologia, Universidade de Évora, Núcleo da Mitra, Ap. 94, Évora, 7002-554, Portugal.|Departamento de Microbiologia, Laboratório de Microbiologia do Solo, Universidade Federal de Santa Catarina, Florianópolis, SC, 88040-900, Brazil.
authors: Francisco X
authors: FX
authors: Nascimento
authors: Nemalab/ICAAM - Instituto de Ciências Agrárias e Ambientais Mediterrânicas, Departamento de Biologia, Universidade de Évora, Núcleo da Mitra, Ap. 94, Évora, 7002-554, Portugal.
authors: Margarida
authors: M
authors: Espada
authors: Nemalab/ICAAM - Instituto de Ciências Agrárias e Ambientais Mediterrânicas, Departamento de Biologia, Universidade de Évora, Núcleo da Mitra, Ap. 94, Évora, 7002-554, Portugal.
authors: Pedro
authors: P
authors: Barbosa
authors: Departamento de Microbiologia, Laboratório de Microbiologia do Solo, Universidade Federal de Santa Catarina, Florianópolis, SC, 88040-900, Brazil.
authors: Márcio J
authors: MJ
authors: Rossi
authors: Nemalab/ICAAM - Instituto de Ciências Agrárias e Ambientais Mediterrânicas, Departamento de Biologia, Universidade de Évora, Núcleo da Mitra, Ap. 94, Évora, 7002-554, Portugal.|Department of Environmental Biology College of Bioscience & Biotechnology, Chubu University, 1200 Matsumoto, Kasugai, Aichi, 487-8501, Japan.
authors: Cláudia S L
authors: CS
authors: Vicente
authors: Nemalab/ICAAM - Instituto de Ciências Agrárias e Ambientais Mediterrânicas, Departamento de Biologia, Universidade de Évora, Núcleo da Mitra, Ap. 94, Évora, 7002-554, Portugal.|Departamento Ciências da Vida, EPCV Universidade Lusófona de Humanidades e Tecnologias, C. Grande 376, Lisboa, 1749-024, Portugal.
authors: Manuel
authors: M
authors: Mota
mesh_terms: D000818:Animals; D060026:Endophytes / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology*; D028223:Pinus / Q000254:growth & development / Q000382:microbiology* / Q000469:parasitology*; D010935:Plant Diseases / Q000469:parasitology*; D012705:Serratia / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology*; D013559:Symbiosis; D017187:Tylenchida / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology*