IDENTIFICATION AND CHARACTERIZATION OF A DIRIGENT PROTEIN THAT CONTROLS THE BIOSYNTHESIS OF (+)-GOSSYPOL IN COTTON
Insect Control and Cotton Disease Research Unit
2013 Annual Report
1a.Objectives (from AD-416):
1. Express cDNAs isolated from cotton that code for dirigent proteins in an insect/plant tissue culture system and assay for dirigent activity including the biosynthesis of (+)- or (-)-gossypol.
2. Transform cotton plants to optimize (+)-gossypol formation.
1b.Approach (from AD-416):
Cooperator will express appropriate cDNA sequences from cotton provided by the ARS cooperator in an insect/plant tissue culture system and test their activity for formation of (+)- or (-)-gossypol.
Gossypol is a compound that occurs naturally in cottonseed and is toxic to non-ruminant animals. Gossypol occurs in two forms; one is toxic and the other is relatively nontoxic. The goal of this project is to identify and characterize factors in the plant that control the production of the gossypol form that is minimally toxic to non-ruminant animals. In FY 2013, genetic material from flower petals of various species of Gossypium was extracted. Comparisons were made among the species to identify unique sequences that may control the production of the nontoxic form of gossypol. Additional plants are currently being grown that will provide genetic variation, especially within the accessions of Gossypium hirsutum var. marie galante. Ongoing work by this project will advance our understanding of the genetic control of the (+)- and (-)-gossypol ratio in seed, and will provide foundational information for work to develop new cotton cultivars with low (-)-gossypol seed that can be safely fed to non-ruminant animals and thus expand utilization of cottonseed and enhance profitability of U.S. farmers.