硝酸还原酶及其活力调节因子

硝酸还原酶因其在氮素同化过程中的作用,越来越引起人们的重视。许多生物工作者对此做了大量的工作。本文对硝酸还原酶的性质及其活力调节因子作了概括总结。硝酸还原酶是一种诱导酶,它的活力受内部和外部两方面因子的调节。内部因子包括:(1)机物种类和品种;(2)生育期;(3)植株部位;(4)苗龄和叶龄。外部因子包括:(1)硝态氮浓度;(2)光;(3)水分(4)温度;(5)外源激素;(6)金属离子;(7)pH值;(8)氨态氦和硝态氮;(9)某些代谢中间产物。对硝酸还原酶特性及其活力调节因子的了解,不但有助于培育优良的作物品种,而且可以通过改变外界条件。使作物的氮素代谢向人们所希望的方向发展。

NITRATE REDUCTASE AND ITS ACTIVITYREGULATING FACTORS

Nitrate Reductasc (NR) is increasingly noted because of its important role in nitrate assimilation. Many biological workers have done a lot of studies in this field. This article mainly dealt with the characteristi(?)s of NR and its activity-regulating factors based on the literatures published in recent years. NR is an inducible enzyme, its activity is influenced by both internal and external factors. The internal factors included: (1)species and cultivars; (2) growing periods; (3) parts of plant, and (4) ages. The external factors were: (1) NO(?) content in medium; (2) light; (3)water; (4)temperature; (5) exogenous phyto-hormones; (6) metal ions; (7)pH values, (8)N-N(?)and N-NH_4~+ and (9)some metabolic intermediate substances. The knowledge about NR could help us to breed new cultivars and to control the nitrogen assimilation.