The focus of the group is inducible resistance in plants, primarily systemic acquired resistance (SAR). SAR signalling is initiated by a localized infection of a plant by pathogens that induce a salicylic acid (SA)-mediated defence response. In the laboratory, SAR is generally induced via the initiation of a localized hypersensitive response, an SA-dependent defence reaction that resembles programmed cell death (HR; see lesions caused by tobacco mosaic virus (TMV) upon primary (1°) infection below). During the execution of the HR, a signal of mostly unknown nature/composition is sent to the systemic healthy parts of the plant to establish a state of heightened resistance (SAR; see lesions caused by 2° TMV infection below).
SAR is long lasting and acts against a broad range of pathogens while its maintenance does not significantly affect plant yield. The latter characteristic makes that SAR signals are now generally considered good candidates for protection of crop plants from disease. Our laboratory focuses on the identification and characterization of SAR signals in the model organism Arabidopsis thaliana. To this end, extracts from induced Arabidopsis plants are analyzed by different mass spectrometry-based techniques. Candidate SAR signalling factors are under and over expressed in Arabidopsis and other plant species, and their role in pathogen defence is tested in pathological assays with different bacteria and fungi.
