Regulation of plant resistance to host-adapted biotrophic pathogens

• Antragstellerin: Professorin Dr. Jane E. Parker
• Fachliche Zuordnung: Organismische Interaktionen, chemische Ökologie und Mikrobiome pflanzlicher Systeme
• Förderung: Förderung von 2007 bis 2015
• Projektkennung: Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 38990813

An important layer of plant immunity against host-adapted biotrophic pathogens is controlled by the nucleo-cytoplasmic protein EDS1 which limits virulent pathogen growth and connects activated immune receptors to the triggering of localized host cell death and systemic resistance. To regulate these host responses, EDS1 directs both salicylic acid (SA)-dependent and SA-independent processes. Here, we are characterizing an Arabidopsis SA-independent branch of EDS1 signalling involving the flavin-dependent monooxygenase FMO1 and a cytosolic nudix hydrolase (NUDT7) as positive and negative components, respectively. By analysis of Arabidopsis mutant combinations we establish that EDS1 controls interactions between chloroplast-derived O2•− (superoxide) and SA as part of a mechanism limiting host cell death. Both SA-antagonized and SA-promoted processes are required for full resistance to host-adapted biotrophic pathogens. By metabolite analysis with SPP partners we also identify 2,3-dihydroxy benzoic acid (2,3-DHBA) as a xylose-conjugate whose pathogen-induced accumulation depends strongly on EDS1 and FMO1. We will continue to characterize the molecular function and position of FMO1 in the EDS1 pathway using genetics, cell localization and interaction studies and gene expression/metabolite profiling. We will also explore which processes of Arabidopsis post-invasive defence are targeted by biotrophic pathogen effectors to promote disease. Our studies should provide insights to mechanisms of host cellular reprogramming during biotroph infection and in immunity.

• DFG-Verfahren: Schwerpunktprogramme
• Teilprojekt zu: SPP 1212: Microbial reprogramming of plant cell development