Transformation of Gossypium hirsutum and Gossypium barbadense by Rhizobium rhizogenes: Hairy root induction and gossypol production

Gossypol and its methylated derivatives are produced in the leaves, seeds, stems, and roots of cotton plants. Although gossypol is toxic to many animals, other uses for gossypol are actively being investigated. To develop an experimental model for gossypol biosynthesis, a project to produce hairy root cultures from cotton was initiated. Hairy root cultures from two cotton species, Gossypium hirsutum (DPL 90) and Gossypium barbadense (Sea Island) were developed in this study. Gossypol was synthesized and retained by hairy root tissue at levels similar to that found in cottonseed. Cultures originating from a single transformation event were more similar in their gossypol levels than cultures originating from different transformation events. The effects of media composition, temperature, and addition of elicitors and a signal transducer on culture growth rate and gossypol content were also monitored. The hairy root culture system developed by this project is a suitable model for studying gossypol biosynthesis and nematode resistance