P-343 - Harnessing Burkholderia strains for the biocontrol of Botrytis cinerea and Fusarium graminearum in crops

The Burkholderia genus is renowned for its remarkable metabolic versatility, however, its metabolites remain unexplored for plant disease biocontrol. This study aimed to evaluate the biocontrol potential of Burkholderia strains against two major plant pathogenic fungi, Botrytis cinerea in tomato and Fusarium graminearum in wheat. In vitro agar plate assays showed strong antagonistic activity against B. cinerea, while inhibition of F. graminearum was comparatively lower. For in planta assays, tomato and wheat plants were used in leaf disc and detached leaf assays, respectively. Spore suspensions of B. cinerea R16 and GFP-tagged F. graminearum PH1 were co-inoculated with Burkholderia suspensions. Infected controls and PBS-treated negative controls were included. Disease progression was monitored using multispectral imaging, tracking key spectral health parameters such as chlorophyll fluorescence and chlorophyll index over time. The performance of the strains was highly variable in planta and was differential in both plant species. In tomato plants, fifteen Burkholderia strains were active against B. cinerea while in wheat plants, eighteen Burkholderia strains were highly active and reduced the cGFP signal significantly, indicating a reduction in F. graminearum biomass. To further elucidate the mechanisms underlying these biocontrol effects, whole-genome sequencing is currently underway to identify potential biosynthetic gene clusters associated with antifungal activity.