Allelopathy offers a direct opportunity for the host plant to counter development of a parasitic plant by deploying antagonistic secondary metabolites at the early stages of infestation. Little progress has been made in exploiting allelopathy for controlling parasitic plants, largely because of weakened defence secondary metabolism of crop plants as a consequence of breeding for other priorities. However, forage legumes of the genus Desmodium when grown as an intercrop substantially interfere with infestation of maize by Striga spp. through allelopathy. One aspect of the chemistry underpinning this control involves C-glycosylated flavonoids, specifically 6-C-α-l-arabinopyranosyl-8-C-β-d-glucopyranosylapigenin. Currently, the genes for enzymes involved in the crucial step in the biosynthesis of C-glycosylated flavonoids are being identified, with attempts to transfer such genes to cowpea. This approach to exploit allelopathy could potentially produce food crops benefiting directly from this Striga-controlling trait.
- Hamilton ML, Kuate SP, Brazier-Hicks M, Caulfield JC, Rose R, Edwards R, Torto B, Pickett JA, Hooper AM (2012) Elucidation of the biosynthesis of the di-C-glycosylflavone isoschaftoside, an allelopathic component from Desmodium spp. that inhibits Striga spp. development. Phytochemistry 84:169–176CrossRefPubMedGoogle Scholar
- Kersher F, Franz G (1987) Biosynthesis of vitexin and isovitexin: enzymatic synthesis of the C-glucosylflavones vitexin and isovitexin with an enzyme preparation from Fagopyrum esculentum M. seedlings. Z Naturforsch 42c:519–524Google Scholar
- Khan ZR, Pickett JA, Hamilton ML, Hassanali A, Hooper AM, Kuate SP, Midega CAO, Pittchar J, Torto B (2010b) Control of stem borers and Striga in African cereals: a low input push-pull approach with rapidly expanding impact. Aspects Appl Biol 56:145–151Google Scholar