Hemoglobin-stimulated growth and antioxidant activities in cultured cotton cells

Changes in cellular reactive oxygen scavenging enzymes were assessed in suspension-derived cells of cotton (Gossypium herbaceum) cv. Dhumad following culture with a commercial bovine hemoglobin (Hb) solution (Erythrogen) at 1:100-1:1000 (v:v). Mean (+/- SEM) fresh (f.wt.) and dry weights (d.wt.) of cells after 25 d of culture were significantly (p <.05) greater in medium supplemented with 1:750 and 1:1000 (v:v) Erythrogen, compared to controls lacking Erythrogen. For example, with 1:750 (v:v) Erythrogen, mean cell f.wt. and d.wt. were increased by 45 and 31%, respectively. Total soluble cellular protein increased by 141, 176, and 191% with Erythrogen at 1:50, 1:750, and 1:1000 (v:v), respectively. Cellular catalase and glutathione reductase activities decreased significantly (p <.05) following addition of low concentrations (1:1000 and 1:750 v:v) of Erythrogen to culture medium. However, increasing the concentration of Erythrogen to a maximum of 1:100 (v:v), caused a concomitant increase in catalase to a maximum of 62% over control. Mean total superoxide dismutase activity increased linearly with increasing Erythrogen concentration, reaching a maximum mean value over 2-fold greater than control with 1:100 (v:v) Erythrogen. A similar trend was observed in cellular H2O2 content, which reached a maximum of 98% over control with 1:250 (v:v) Erythrogen. These results demonstrate that culture of cotton cells with Hb solution causes changes in cellular oxygenation sufficient to modify cellular antioxidant status.