Abstract

Powdery mildews are phytopathogens whose growth and reproduction are entirely dependent on living plant cells. The molecular basis of this lifestyle, obligate biotrophy, remains unknown. I will present the genome of a powdery mildew of grasses and a comparison with those of two powdery mildews pathogenic on dicotyledonous plants. The comparative genome analysis reveals unexpected insight in mechanisms underlying an exclusively biotrophic lifestyle and a set of genes that might have roles in host species-specific adaptations. Current concepts of the plant innate immune system are largely based on two forms of immunity that engage distinct classes of immune receptors. The existence of this elaborate immune system creates a potential paradox: how then can plants serve in nature as hosts of a staggering diversity of commensalistic and mutualistic microorganisms including endophytes throughout their life cycle? I will present our approaches to survey and characterize the bacterial microflora of Arabidopsis roots grown in natural soil. I will discuss whether host determinants shape these root-associated microbial communities.

http://www.mpiz-koeln.mpg.de/english/research/pmi-dpt/