Elucidating the Role(s) of Effector-like proteins in the ectomycorrhizal Symbiosis
PI : Claire Veneault-Fourrey (UMR 1136 Interactions Arbres/Micro-organismes – IAM)
Collaboration :
Jonathan Plett, University of Western Sydney, Australia
Oak Ridge National Laboratory, Tennessee, US
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Context — Ectomycorrhizal mutualistic symbiosis between tree roots and fungal hyphae, are essential for tree health and thus forest sustainability. In exchange for carbohydrates, ECM fungi improve mineral supply of the trees. To facilitate nutrient exchanges, root morphology is strikingly altered and a mixt symbiotic organ (ectomycorrhiza : ECM) is formed. The signals from the two partners that promote and mediate the ECM symbiosis have remained mainly uncharacterized. Recent studies highlight the importance of fungal small-secreted proteins/peptides (SSP)-based communication (dialogue) between plants and their symbionts. These SSPs are called effectors as a reference towards effectors produced by plant pathogenic microbes to suppress or inactivate plant immunity thereby allowing access to plant nutrient stores.
Objectives — Understanding the roles of effector proteins (such as Mycorrhizal induced Small Secreted Proteins : MiSSPs), and the targeted hormone signalling pathways used to restructure the plant host cell to promote mutualism is the fundamental aim of this project.
Approaches — We propose to elucidate the plant cellular processes targeted by fungal effectors using a multidisciplinary approach and to identify fungal effectors able to target hormone-receptor or hormone-mediated signalling such as Salicylic Acid (SA) and Giberrelic Acid (GA).
Expected results and impacts — Characterizing interactions between plants and microbes is critical to achieve long-term ecosystem productivity. Demonstrating that receptors for major hormones involved in symbiosis development are targeted by a diverse set of fungal MiSSPs would revolutionize the current models of symbiosis development and plant-microbe interactions.
