Inoculation of Pochonia chlamydosporia triggers a defense response in tomato roots, affecting parasitism by Meloidogyne javanica

• Published in: Microbiological research 2023-01, Vol.266, p.127242-127242, Article 127242
• Main Authors: Gouveia, Angélica de Souza, Monteiro, Thalita Suelen Avelar, Balbino, Huarlen Marcio, Magalhães, Fernanda Corbelli de, Ramos, Maria Eduarda Soares, Moura, Vitor Augusto Silva, Luiz, Paulo Henrique Dionizio, Oliveira, Maria Goreti de Almeida, Freitas, Leandro Grassi de, Ramos, Humberto Josué de Oliveira
• Format: Article
• Language: English
• Subjects: active ingredients; aminocyclopropanecarboxylate oxidase; Biocontrol; biological control agents; chlorogenic acid; endophytes; Flavonoids; fungi; genes; host plants; jasmonic acid; Meloidogyne javanica; metabolites; Metabolomics profile; naringenin-chalcone synthase; parasitism; phenylalanine ammonia-lyase; Phytohormones; plant hormones; Pochonia chlamydosporia; proteinase inhibitors; respiratory burst; Root-knot nematodes; species; tomatoes
• ISSN: 0944-5013; 1618-0623
• DOI: 10.1016/j.micres.2022.127242

Pochonia chlamydosporia is a soil-dwelling fungus and biological control agent of nematodes, active ingredient in commercial bionematicides. The fungus is also endophytically associated with the roots of several plant species, promoting their growth and inducing systemic resistance. In this study, different pathways and tomato defense metabolites were studied to identify mechanisms induced by P. chlamydosporia that contribute to the control of Meloidogyne javanica, at early and late developmental stages. Some defense responses activated by the fungus appeared related to the nematode life cycle. Among the evaluated biochemical analysis, root colonization of P. chlamydosporia showed an increase in the concentration of phenolic compounds, such as chlorogenic acid. In addition, the expression of some host plant genes was also modified. The interaction of the fungus with roots parasitized by M. javanica resulted in the highest expression of Phenylalanine Ammonia-Lyase (PAL), Chalcone synthase (LECHS 2), and Protease Inhibitor (PI1) genes at 24 days post-inoculation. At the second sampling time (44 days), there was an increase in the expression of the Respiratory Burst Oxidase Homolog (RBOH) gene. Fungus reduced the expression of the ACC-oxidase and Pathogenesis-Related Proteins 1 (PR-1) genes in roots. Moreover, P. chlamydosporia inoculation changed metabolites and phytohormone profiles of the gall formed by M. javanica. Plant defense response appeared to involve the jasmonic acid and phytosphingosine cascades. With this analysis, it was possible to propose new molecular mechanisms induced by the fungus that contribute to the control of M. javanica.