Submitted to: Journal of Experimental Botany
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 14, 2005
Publication Date: April 1, 2005
Citation: Cooper, L.D., Doss, R.P., Price, R.R., Nelson, K., Oliver, J.E. 2005. Application of Bruchin B to pea pods results in the up-regulation of CYP93C18, a putative isoflavone synthase gene, and an increase in the level of pisatin, an isoflavin phytoalexin. Journal of Experimental Botany. 56(414): 1229-1237. Interpretive Summary: Bruchins are chemical compounds associated with the eggs of certain insects, most notably pea weevils, that stimulate cell division when applied to pods of peas and some related legumes. This cell division results in the formation of wart-like growths that inhibit entry into the pod of the larvae of the insects that laid the eggs. Hence, the plant, by detecting and responding to the bruchin, is able to resist infestation by the insect, and it can be said that bruchins mediate a mechanical defense response. In this work we show that in addition to stimulation of cell division, application of bruchins to pea pods causes changes in expression of a gene that is involved in synthesis of a chemical defense compound; namely the isoflavone pisatin. Although this compound is normally thought to be involved in defending pea plants against fungal pests, it is possible that it is also active against insects.