【摘要】 低温贮存期间,玉米叶片PEP羧化酶活性随贮存时间的延长而明显降低,对效应剂Gly的敏感性也减弱。多羟基醇(甘油和山梨醇)以及PEP羧化酶的正效应剂G-6-P在与Gly和甘油同时作用时,对PEP羧化酶在低温贮存期间的活性和对Gly的敏感性均有保护效应,且对两者的保护程度相一致,表明低温贮存期间PEP羧化酶对效应剂敏感性减弱与其低温失活有直接关系。更多还原

【Abstract】 In this thesis, the effect of low temperature on the PEPCase activity of maize leaves and its regulatory properties were studied.PEPCase was inactivated at low temperature, the rate of inactivation increased as the temperature was reduced from 4 ℃ to 0℃, and PEPCase were less sensitive to Gly during low temperature incubation. The presence of polyhydric alcohol (sorbitol or glycerol or both), G-6-P or Gly and glycerol could not only protect PEPCase against low temperature inactivation, but also make it sensitive to Gly under low temperature. The protection of PEPCase by those reagents against low temperature insensitivity to Gly were correlated with the protections of that for PEPCase against low temperature inactivation suggested that the insensitivity of PEPCase to effector at low temperature was due to the low temperature inactivation of PEPCase. Sorbitol was superior to glycerol in protecting PEPCase against inactivation and insensitivity to effector during low temperature incubation, this suggested that the protective effects of polyhydric alcohol on PEPCase was related to the number of hydroxy groups. Only the presence of G-6-P however, had not effect.更多还原