Examining Fusarium graminearum and Fusarium avenaceum interactions in durum wheat

Citation

Harris, L.J.*, Bosnich, W., Johnston, A., Kwan, R., Schneiderman, D., Blackwell, B., Bahadoor, A., Gleddie, S. Examining Fusarium graminearum and Fusarium avenaceum interactions in durum wheat. Proceedings of the 8th Can. Workshop on Fusarium Head Blight, Ottawa, ON Nov. 20-22, 2016. P. 18, Invited talk.

Abstract

Fusarium graminearum and F. avenaceum are known to co-contaminate Canadian durum wheat samples, leading to FHB and grain contaminated with multiple mycotoxins. Each of these species produces its own diverse set of mycotoxins and other secondary metabolites, of which only a small proportion are overlapping. For example, while F. graminearum produces trichothecenes, zearalenone, and culmorin, F. avenaceum produces enniatins, moniliformin, and antibiotic Y. To study what happens when these two species encounter each other in the host plant, F. graminearum and F. avenaceum strains were inoculated individually and in combination in durum wheat spikes and monitored over 7 days. We assessed visual disease symptoms, estimated species-specific fungal biomass, and determined DON concentrations. Overall, the interaction of these two species led to reduced disease and DON levels compared to F. graminearum inoculations alone. Global transcriptome analysis of F. graminearum exposed to F. avenaceum secondary metabolites in liquid culture revealed that a F. graminearum ABC transporter gene is highly induced when F. graminearum is exposed to purified enniatin B1. This transporter gene is only induced in planta when F. graminearum is co-inoculated with F. avenaceum. The F. graminearum ABC transporter protein has been successfully expressed in yeast (Saccharomyces cerevisiae) for functional studies and has been shown to rescue yeast from enniatin toxicity. We are investigating what role this transporter may play in interspecies interactions.

Publication date

2016-11-20