Non-host interactions to detect anti-Fusarium substances

Fusarium are ubiquitous filamentous fungi and a major threat for numerous plant or animal species [1]. They are often considered as highly resistant to conventional antifungal treatments. The Fusarium genus also contains isolates considered as endosymbiontic or saprotrophitic strains. These lifestyles are dispersed over a large phylogenetic spectrum [2], which suggests either multiple evolution of the same trait or enormous capacity of each strain to adapt to the available environment or host. We've shown that Fusarium strains have genuine capacity to develop on various host and we made use of these adaptation capacities to establish non-host interactions on vine leaves. Some Fusarium strains developed efficiently as necrotrophic pathogens while others adopt less aggressive mode of interaction on susceptible vine varieties as Chasselas. Correspondingly, some Vitis species or varieties were more resistant and restrained efficiently fungal growth. To identify natural substances involve in the control of fungal development, we set-up a sensitivity test in 96 well plates to screen for anti-Fusarium activity of natural extracts. The test on solid growth medium enables to screen natural extracts on several filamentous fungi and we compared fungal susceptibility to these extracts using various human and plant pathogens.

Keywords: Fusarium, antifungals

Acknowledgement: This work was supported by Swiss National Science Foundation Sinergia Grant CRSII3_127187 (to J.-L. W. and K. G.)

References: 1. Schurch S et al. (2010) Agrarforschung Schweiz 1: 442–445.

2. Zhang et al. (2006)J Clin Microbiol 44: 2186–2190