Page Banner

United States Department of Agriculture

Agricultural Research Service

Title: Phytoalexins from Cotton: Induction, Toxicity and Mode of Action

item Puckhaber, Lorraine - TEXAS A&M UNIVERSITY

Submitted to: Plant Growth Regulator Society of America Meeting
Publication Type: Proceedings
Publication Acceptance Date: August 2, 1995
Publication Date: N/A

Technical Abstract: The phytoalexins produced by the wilt resistant Seabrook Sea Island (SBSI) (Gossypium barbadense) cotton produces a mixture of methylated and unmethylated phytoalexins, while the wilt susceptible Rowden (G. hirsutum) produces almost exclusively unmethylated phytoalexins. Phytoalexins play an important role in the defense response of cotton to V. dahliae infection. For the wilt resistant SBSI, our data suggests the quickness and concentration of the phytoalexins are more critical in conferring resistance than is methylation of the phytoalexins. Furthermore, the effectiveness of the most important phytoalexin desoxyhemigossypol (dHG), resides in its solubility and its ability to readily form free radicals. The mode of action of dHG involved the formation of H2O2.

Last Modified: 4/22/2015