Akademik Veri Yönetim Sistemi
ACTA PHYSIOLOGIAE PLANTARUM, cilt.35, sa.1, ss.241-251, 2013 (SCI-Expanded)
This experiment was conducted to monitor the influence of foliar progesterone application on the chilling tolerance of chickpea seedlings. Twelve-day-old chickpea seedlings were treated with 10(-7) mol L-1 progesterone. After 12 h, the seedlings were exposed to day/night temperatures of 9/5 A degrees C for 72 h in a growth chamber. Chilling stress resulted in remarkable increase in the activities of antioxidant enzymes including superoxide dismutase (SOD), guaicol peroxidase (POX), catalase, ascorbate peroxidase (APX) and glutathione reductase, as well as the level of antioxidant compounds like ascorbic acid, glutathione and proline. In a similar manner, chilling stress affected significantly oxidative stress indicators measured as superoxide production, electrolyte leakage, hydrogen peroxide (H2O2) and malondialdehyde contents. The values of these parameters were lesser in progesterone-applied seedlings that were associated with higher activities of antioxidant enzymes and greater levels of antioxidant compounds in these seedlings. A highly significant correlation was recorded between SOD, POX and APX activities and their isozymes. This correlation confirmed enhanced activities of these enzymes. In addition, progesterone application ameliorated chilling-induced decrease in relative leaf water content (RLWC) and chlorophyll content. Freezing tolerance, showed by thermal analysis method, proved that progesterone application improved chilling tolerance of chickpea seedlings by lowering freezing point from -4 to -5.5 A degrees C. It is possible that chilling tolerance induced by progesterone is related to elevation of RLWC, chlorophyll content and antioxidative activity, and thereby decrease in oxidative stress indicators.