Functional characterization of a new effector-protein family (DELD) from Piriformospora indica induced during the biotrophic colonization of host roots

• Antragstellerin: Professorin Dr. Alga Zuccaro
• Fachliche Zuordnung: Organismische Interaktionen, chemische Ökologie und Mikrobiome pflanzlicher Systeme
• Förderung: Förderung von 2012 bis 2016
• Projektkennung: Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 223174009

The symbiotic endophyte Piriformospora indica (Sebacinales, Basidiomycota) colonizes the root cortex of vascular plants with beneficial effects to the host. Recent cytological studies in barley and Arabidopsis showed that upon penetration of the root, P. indica establishes a biotrophic interaction during which fungal cells are encased by the host plasma membrane. Large-scale transcriptional analyses of fungal and plant responses have shown that perturbance of plant hormone homeostasis and secretion of fungal lectins and other small proteins (effectors) may be involved in the evasion and suppression of host defenses at these early colonization steps. Aim of this proposal is to identify and characterize the key effectors involved in the establishment of biotrophy. In particular we will focus on the functional characterization of small secreted proteins (SSPs) induced during the early phase of root colonization. These include a novel P. indica-specific putative effector family, which is characterized by a 7 amino acid conserved C-terminal motif, RSIDELD. To better characterize the function of the DELD proteins at the molecular level we will perform the following experiments: 1) Knock downs (RNAi) in P. indica of candidate genes selected on the basis of expression profiles; 2) Localization studies using GFP- and mCherry-fusions for effectors where knock down affects symbiotic development; 3) Identification of plant proteins interacting with selected effectors by yeast two hybrid (Y2H) screen and 4) Plant RNAi or T-DNA insertion mutants lacking effector-interactors will be tested for altered root colonization by P. indica.

• DFG-Verfahren: Sachbeihilfen