Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Abstract Only
Publication Acceptance Date: November 10, 2004
Publication Date: January 4, 2005
Citation: Dowd, M.K., Moss, S.C., Pelitire, S.M., Triplett, B.A. Optimal growth and secondary metabolity production from cotton hairy roots. 2005 Beltwide Cotton Conference, January 4-7, New Orleans, LA . p. 2122. Technical Abstract: Hairy root cultures are an ideal system to investigate metabolite production and regulation in cotton. As part of our studies on cotton hairy root cultures, experiments were conducted to optimize culture growth rate and secondary metabolity production. In addition to gossypol (a disesquiterpene with potentially valuable anti-cancer properties), transformants derived from both Gossypium barbadense and G. hirsutum contained measurable amounts of 6-methoxy-gossypol and 6, 6'-dimethoxy-gossypol. Individual cultures exhibited considerabole variability in the ability to produce gossypol. Media composition, culture time, and temperature were all found to influence culture growth and metabolite production. Growth rates were determined by gravimetric measurement, and gossypol levels were determined by HPLC analysis. To date, the highest growth rate and the greatest metapolite productivity was obtained from cultures grown on Gamborg B5 media. The optimal temperature for hairy root growth was 28 degrees C, and the optimal temperature for total gossypol level was 3l degrees C. Total gossypol productivity (gossypol level x culture mass) was slightly higher at 31 degrees C than at 28 degrees C. Variability and stability of gossypol production within individual high-producing cultures was also studied. Although considerable variability in gossypol levels was observed among cultures, the ability to produce gossypol was maintained over many media transfers. Total gossypol levels up to 4% (dry weight basis) have been obtained from some cultures.