Effects of low temperature on the nitrogen metabolism by the activities of key root enzymes in Malus baccata under different supply of nitrogen levels
WANG Ying
LV De-guo
QIN Si-jun
MA Huai-yu
LIU Guo-cheng
MENG Qian
Abstract：The effect on activities of enzymes in nitrogen metabolism, soluble protein and free proline content were studied under low temperature and different nitrogen levels using Malus baccata Borkh.The results indicated that the glutamine syn-thetase (GS) activity in slow cooling treatment and rapidly coohng treatment was increased,but the glutamate synthase (NADH-GOGAT) and glutamate dehydrogenase(NADH-GDH) activity was decreased obviously.The enzymes of nitrogen metabohsm were seriously affected by rapidly cooling treatment than that of slowly cooling treatment.There was different re-actions of enzymes of nitrogen metabolism on different nitrogen levels, GS activity followed as medium nitrogen> high nitro-gen>low nitrogen, NADH-GOGAT activity followed as low nitrogen> high nitrogen>medium nitrogen, and NADH-GDH ac-tivity followed as high nitrogen>medium nitrogen>low nitrogen.Low temperature obviously increased GS/GDH ratio,espe-cially under high nitrogen and low temperature.Low temperature decreased soluble protein content of root, and the content of soluble protein was the lowest in rapidly cooling treatment.No matter what temperature soluble protein followed as high nitro-gen>medium nitrogen>low nitrogen.The content of free proline increased under slowly cooling treatment and rapidly cooling treatment, especially in rapidly coohng treatment.The nitrogen levels had no obvious effect on the content of free proline.
Keywords：Malus baccata BorkhLow temperatureGlutamine synthetaseGlutamate synthaseGlutamate dehydrogenaseFree proline
Publication Date：2009-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：6( 769-774 )