甘蔗不同基因型2种光合酶的热稳定性

THERMOSTABILITY OF TWO PHOTOSYNTHETIC ENZYMES IN SUGARCANE GENOTYPES

甘蔗不同基因型之间叶片 PEP 羧化酶的热稳定性有较大的差异。甘蔗叶片 PEP 羧化酶对高温敏感,在伸长盛期酶热稳定性相对较高;随着环境温度的下降,到伸长后期酶热稳定性明显变低,甘蔗叶片 NADP-苹果酸酶的热稳定性很高,不同基因型之间差异不大。显然,热逆境不会导致 NADP-苹果酸酶的严重失活而影响光合作用。

It was showed that the thermostability of leaf PEP carboxylase was different be- tween 7 sugarcane genotypes.Leaf PEP carboxylase of sugarcane was sensitive to high tem- perature.The enzyme was relatively thermostable at abundant elongating stage,and at late elongaing stage it became less thermostable markly as the environmental temperature varied from high to low.Leaf NADP-malic enzyme of sugarcane was very thermotable.No dif- ferences were found between 7 sugarcane genotypes.Apparently,the thermal environment could not easily influence the photosynthesis of sugarcane by inactivating the enzyme seriously.