Comparative Analysis of the Stage- and Species-Specificity of Rust Secretomes.
Final Report Abstract
Rust fungi are obligate biotrophic fungi that do not actively kill their host but are dependent on living host tissue to complete their life cycle. In order to establish and to maintain this symbiotic interaction, biotrophic pathogens use so called effector proteins. These effector proteins are part of the signaling between pathogen and plant and have been shown to suppress plant defense responses and probably also play a role in influencing the plant to supply nutrients to the pathogen. For the few effector proteins identified for biotrophic fungal pathogens so far only few general features could be identified: they are secreted, predominantly secreted from the haustorium, specific to the pathogen lineage or species, and they are of unknown function. Effector proteins can give valuable insights into plant pathogen interaction and they are thought to be valuable targets for pathogen control. In the course of this work, using either the Yeast Signal Sequence Trap or next generation sequencing, we studied the haustorial secretomes of the two rust species Uromyces appendiculatus, and Phakopsora pachyrhizi, the causative agents of Common Bean Rust and Asian Soybean Rust respectively. Among these secreted proteins we were able to identify, mainly based on lineage specificity, several candidate effectors and families of candidate effectors. For candidate effector families we did pattern analysis and built partial phylogenies. The foundation for the identification of possible plant interaction partners of these proteins, a vital step in elucidating their function, has also been laid in establishing a Yeast Two Hybrid Screen.
