Specific projects:

Transcriptional and metabolic patterns of barley for basal disease resistance and susceptibility to powdery mildew

Involvement of transcriptional reprogramming in interaction with the powdery mildew fungus Bgh. 1. Fungal attack activates cell surface RLK and apoplastic signalling. 2. RLK signaling is postulated to activate RACB by stimulating GDP-to-GTP exchange via guanidine nucleotide exchange factors. 3. Bgh might additionally address RACB via virulence effector functions. Activated RACB influences the cytoskeleton (4.) and gene expression (5.). 6. Cytoskeleton remodelling might directly support fungal entry. 7. RACB-modulated gene expression supports expression of RLKs and apoplastic signalling components in a positive feedback loop. This might again sustain RACB signalling to fungal entry.

In barley, patterns of gene expression globally change in response to attack from the biotrophic fungal pathogen Blumeria graminis f.sp. hordei. During this response about a quarter of all barley genes change expression in a statistically significant way (Schnepf et al. 2018). However, it is not understood, in how far these dramatic changes reflect immune responses that actually restrict infection, global re-allocation of metabolism, or even reprogramming of the susceptible host by fungal virulence effectors. We analyse these transcriptional patterns by comparing them in little susceptible and super-susceptible barley genotypes (differentially expressing the RACB susceptibility gene). Among others, we focus on receptor-like kinases (RLK), apoplastic cell wall biogenesis and cell cycle genes (see also Schnepf et al. 2018, Mol Plant Pathol).