1ULTRA-WEAK LUMINESCENCE IS A SENSITIVE METHOD TOEVALUATE CADMIUM RESISTANCE OF MAIZE VARIETIES

摘要

In this paper, the delayed ultra-weak luminescence (UWL), Nitrate reductase activity and reactive oxygen species (ROS)contents of 3 different maize varieties (Zhengdan958, Jundan20 and Liaoyul 8) under 50mg.L-1 CdC12 stress wereinvestigated. The results showed that the UWL intensity of all 3 maize varieties was decreased and the curve attenuatingaccelerated under the Cd stress. The total photon number reduced 12.8% (zhengdan958), 20.1% (jundan20) and 13.4%(liaoyul8), respectively. The activity of Nitrate reductase, which is a key marker reflecting internal physiology status,decrease 50.12% (zhengdan958), 58.80% (jundan20) and 55.80% (liaoyul8), respectively. The ROS contents increasedremarkably under 50mg.L~(-1)Cdstress, ranging from 35.87% (liaoyul8), 40.90% zhengdan958) to 42.23% (jundan20).From these results we speculated that UWL decreasing tendency was consisting with the change character of Nitratereductase activity, and rather the in vivo metabolism reactions than the ROS contents, was the main resources of ultra-weak photon emitting. Taken together, the UWL and the physiological status are closely related, ultra-weakluminescence could be used as a time-saving, sensitive method for evaluating cadmium stress resistance of differentvarieties of maize.