Shifting from priming of salicylic acid- to jasmonic acid-regulated defences by Trichoderma protects tomato against the root knot nematode Meloidogyne incognita.

Beneficial root endophytes such as Trichoderma spp. can reduce infections by parasitic nematodes through triggering host defences. Little is currently known about the complex hormone signalling underlying the induction of resistance. In this study, we investigated whether Trichoderma modulates the hormone signalling network in the host to induce resistance to nematodes. We investigated the role and the timing of the jasmonic acid (JA)- and salicylic acid (SA)-regulated defensive pathways in Trichoderma-induced resistance to the root knot nematode Meloidogyne incognita. A split-root system of tomato (Solanum lycopersicum) was used to study local and systemic induced defences by analysing nematode performance, defence gene expression, responsiveness to exogenous hormone application, and dependence on SA and JA signalling of Trichoderma-induced resistance. Root colonization by Trichoderma impeded nematode performance both locally and systemically at multiple stages of the parasitism, that is, invasion, galling and reproduction. First, Trichoderma primed SA-regulated defences, which limited nematode root invasion. Then, Trichoderma enhanced JA-regulated defences, thereby antagonizing the deregulation of JA-dependent immunity by the nematodes, which compromised galling and fecundity. Our results show that Trichoderma primes SA- and JA-dependent defences in roots, and that the priming of responsiveness to these hormones upon nematode attack is plastic and adaptive to the parasitism stage.

Martínez-Medina A ，Fernandez I ，Lok GB ，Pozo MJ ，Pieterse CM ，Van Wees SC ... -  《-》

Induction of SA-signaling pathway and ethylene biosynthesis in Trichoderma harzianum-treated tomato plants after infection of the root-knot nematode Meloidogyne incognita.

Leonetti P ，Zonno MC ，Molinari S ，Altomare C ... -  《-》

[The participation of salicylic and jasmonic acids in genetic and induced resistance of tomato to Meloidogyne incognita (Kofoid and White, 1919)].

Zinov'eva SV ，Vasiukova NI ，Udalova ZhV ，Gerasimova NG ... -  《-》

Bio-control agents activate plant immune response and prime susceptible tomato against root-knot nematodes.

Molinari S ，Leonetti P 《PLoS One》

Impact of salicylic acid- and jasmonic acid-regulated defences on root colonization by Trichoderma harzianum T-78.

Martínez-Medina A ，Appels FVW ，van Wees SCM 《-》