The Effect of Different Forms of Calcium on Respiratory Metabolism in Malus baccata Borkh.Roots under Temperature Treatment

摘要

In order to study the effects of exogenous calcium on respiratory metabolism of apple roots during serious fluctuation of temperature (5°C → 20°C→10°C → 0°C),15-leaf seedlings of Malus baccata Borkh.were used as materials,treated with CaAc2 and CaCl2.Comparing with control,total respiratory rate (Vt) of apple roots in both of treatments increased to some extent during temperature changing,furthermore,Vt in CaCl2 treatment was relatively higher.In CaCl2 treatment,EMP respiratory rate kept the highest among the treatments except at 0°C; respiratory rate of TCA cycle and PPP were the highest during the treatment.In Camc2 treatment,respiratory rates of EMP and TCA cycle showed similar tendencies with that of control,however,the former kept at a higher level; PPP respiratory rate was higher than that of control except at 10°C.In conclusion,CaCl2 treatment presented prominent effect in enhancing the ratio of respiratory rates of TCA and PPP to total respiratory,by up-regulating the activities of key enzymes (IDH and G-6-PDH).