2023 03: Healthy Communication

Esca & Co is actually a stress condition - the causing fungi can live many years in the grapevine trunk without causing symptoms. When the plant is exposed to climate stress, as it happens more and more often even in our region, the fungus can sense this and kills its host. In a cooperation with the Institute for Bioactive Compounds (IBWF) in Kaiserslautern we could show that the stressed host accumulates ferulic acid, because this precursor of the wood substance lignin cannot be integrated. The fungus Neofusicoccum parvum has "learnt" to recognise ferulic acid as signal for the crisis of its host and responds bei producing Fusicoccin A, by which it drives the host into suicide, such that it can scavenge the corpse and extract the energy to generate spores for searching a new host. But what happens, when the host is healthy? Then the fungus generates 4-Hydroxyphenyl Acetic Acid, acting as growth promoter that manipulates host immunity in a way that the compound pterostilbene cannot be formed - this is the defence compound targeted against this fungus. Thus, in the absence of climate stress, the fungus might even be beneficial. Can we modulate this sophisticated chemical communication in a way that even under climate stress 4-Hydrophenyl Acetic Acid continues to be formed? This would suppress the outbreak of the disease. That is exactly what we try in frame of our project Microbes for Future (M4F) supported by the Strategic Funds of the KIT presidium. Our work on "healthy communication" has now appeared in the high-ranking journal Plant Cell & Environment:

202. Flubacher NS, Baltenweck R, Hugueney P, Fischer J, Thines E, Riemann M, Nick P, Khattab IM (2023) The fungal metabolite 4-hydroxyphenylacetic acid from Neofusicoccum parvum modulates defence responses in grapevine. Plant Cell & Environment 46, 3575-3591 - pdf