Pathogen inactivation of cruciferous phytoalexins: detoxification reactions, enzymes and inhibitors

Phytoalexins (elicited antimicrobial plant defenses) that are resistant to pathogen degradation provide the producing plants with higher disease resistance levels, and, conversely, their transformation by pathogens makes plants more susceptible to diseases. In this context, the transformation of cruciferous phytoalexins carried out by fungal pathogens is of great concern due to the global significance of cruciferous crops. This review covers the detoxification pathways of cruciferous phytoalexins, the corresponding detoxifying enzymes and their natural and synthetic inhibitors. Paldoxins (inhibitors of fungal detoxifying enzymes) are examined as a potentially sustainable strategy to control plant pathogenic fungi. As a spin-off of the reviewed work, some of the biotransformation reactions could be applied to selectively convert more complex molecules to novel or known products.