Description
Cyanogenic glucosides and glucosinolates are classical phytoanticipins. Following tissue disruption they release toxic hydrogen cyanide and isothiocyanates to provide efficient protection of the plant from generalist herbivorous insects. However, numerous fungi are not deterred by hydrogen cyanide and isothiocyanates. The plant would be able to preferentially combat fungal infection if the metabolon catalyzing cyanogenic glucoside and glucosinolate formation dissociated in a functioning dependent manner. Dissociation of the cytochrome P450s would result in the formation of oximes. Oximes are toxic to cells. Oximes might thus be effective agents towards fungal pathogens if they were accumulated at the precise site of infection. A functioning dependent transient metabolon, which would disassemble upon fungal attack to release reactive oximes at the site of infection, would offer an additional dimension to cyanogenic glucoside and glucosinolate metabolism. The factors controlling the adaptive plasticity of the metabolon remain unknown but this “moonlighting” function may result from the generation of reactive oxygen species. Oximes liberated following disassembly of the metabolon would be highly reactive and form a diverse array of conjugation products. Recently, a broad-spectrum antifungal defense and innate immune response triggered by metabolism of glucosinolates has been reported, although the degradation products involved were not identified. Oxime derived conjugation products could be this sought out signal. This would imply that cyanogenic glucosides would serve a similar function in mediating an innate immune response to pathogen attack. Experimental studies will show whether oxime production mediated by metabolon dissociation constitutes an additional layer of functional complexity of cyanogenic glucoside and glucosinolate metabolism. If so, detonation of an “oxime bomb” to combat fungal infection would supplement the ability of cyanogenic glucoside or glucosinolate containing plants to detonate a “cyanide bomb” or “mustard oil bomb” when attacked by chewing insects. Other P450 based metabolons may serve similar functioning dependent properties.| Period | 4 Oct 2010 |
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| Event title | 10th International Symposium on Cytochrome P450 Biodiversity and Biotechnology |
| Event type | Conference |
| Organiser | John Stegeman |
| Location | Woods Hole, United StatesShow on map |