低温对不同供氮水平下山定子幼苗根系氮代谢的影响  

Effects of low temperature on the nitrogen metabolism by the activities of key root enzymes in Malus baccata under different supply of nitrogen levels

作　　者：王英[1] 吕德国[1] 秦嗣军[1] 马怀宇[1] 刘国成[1] 孟倩[1] 

机构地区：[1]沈阳农业大学园艺学院,北方果树育种与生理生态研究所,沈阳110161

出　　处：《果树学报》2009年第6期769-774,共6页Journal of Fruit Science

基　　金：现代农业产业技术体系建设专项;辽宁省农业攻关计划项目(编号2008204003);辽宁省自然科学基金(编号20082121)

摘　　要：以苹果砧木山定子(Malus baccata Borkh.)实生苗为试材,在3种供氮水平下研究低温对其根系氮代谢关键酶活性、可溶性蛋白质质量分数和游离脯氨酸质量分数的影响。结果表明,逐渐降温处理和迅速降温处理均明显提高了山定子根系谷氨酰胺合成酶(GS)活性,但谷氨酸合酶(NADH-GOGAT)和谷氨酸脱氢酶(NADH-GDH)活性有所下降,迅速降温处理对酶活性的影响较大。氮代谢关键酶活性对氮素水平的反应不一致,GS活性表现为中氮>高氮>低氮,NADH-GOGAT活性表现为低氮>高氮>中氮,NADH-GDH活性表现为高氮>中氮>低氮。低温显著提高了根系GS/GDH比值,尤其是高氮条件下低温处理GS/GDH比值变化最大。低温降低了根系可溶性蛋白质质量分数,迅速降温处理可溶性蛋白质质量分数最低;无论何种温度,可溶性蛋白质质量分数均表现为高氮>中氮>低氮。低温提高了根系游离脯氨酸质量分数,逐渐降温处理脯氨酸质量分数最高,氮素水平对游离脯氨酸质量分数的影响较小。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 synthetase（GS） activity in slow cooling treatment and rapidly cooling treatment was increased,but the glutamate synthase（NADH-GOGAT） and glutamate dehydrogenase（NADH-GDH） activity was decreased obviously.The enzymes of nitrogen metabolism were seriously affected by rapidly cooling treatment than that of slowly cooling treatment.There was different reactions of enzymes of nitrogen metabolism on different nitrogen levels,GS activity followed as medium nitrogen high nitrogenlow nitrogen,NADH-GOGAT activity followed as low nitrogen high nitrogenmedium nitrogen,and NADH-GDH activity followed as high nitrogenmedium nitrogenlow nitrogen.Low temperature obviously increased GS/GDH ratio,especially 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 nitrogenmedium nitrogenlow nitrogen.The content of free proline increased under slowly cooling treatment and rapidly cooling treatment,especially in rapidly cooling treatment.The nitrogen levels had no obvious effect on the content of free proline.

关 键 词：山定子 低温 谷氨酰胺合成酶 谷氨酸合酶 谷氨酸脱氢酶 游离脯氨酸 

分 类 号：S661.1[农业科学—果树学]