Submitted to: Plant Biology
Publication Type: Abstract Only
Publication Acceptance Date: July 15, 2002
Publication Date: December 1, 2002
Citation: Mellon, J.E., Cotty, P.J., Dowd, M.K. 2002. Effects of optically active gossypol on growth parameters of aspergillus flavus [abstract]. Proceedings of the American Society of Plant Biologists Meeting, Plant Biology. p. 190. Technical Abstract: Gossypol, a terpenoid compound produced by cotton (Gossypium hirsutum), is principally localized in lysigenous glands found throughout aerial portions and in roots of the plant. Cottonseed kernels contain up to 1.3% gossypol. Gossypol contributes to plant defenses through anti-insect activity. Aspergillus flavus is a cottonseed fungal pathogen that reduces cottonseed value by production of the potent mycotoxin aflatoxin. Since A. flavus may encounter high concentrations of gossypol during cottonseed invasion, an investigation was initiated into effects of this terpenoid material on A. flavus growth. Racemic gossypol in a concentration range of 0 to 400 ug/mL was tested in a conidia germination assay. Racemic gossypol did not stimulate conidial germination. In a stimulatory environment (potato dextrose medium), however, racemic gossypol concentrations of 250 ug/mL and higher decreased the number of germinated conidia, germ tube length and conidiophore development, and increased hyphal branching. Optically active isomers (+ and -) of gossypol were obtained through crystallization. Effects of these gossypol isomers on the above fungal parameters were compared with the racemic gossypol results.