水分胁迫下硝酸钠对葡萄幼苗氮代谢酶活性的影响

Effect of Sodium Nitrate on Activities of Nitrogen Metabolism Enzymes in Grape Seedlings Under Water Stress

以葡萄品种"维多利亚"(Vitis vinifera L.Victoria)一年生幼苗为试材,采用水培技术,以浓度为5%、10%、15%PEG-6000模拟不同程度的水分胁迫,研究了不同程度水分胁迫下施加硝酸钠对葡萄幼苗氮代谢相关酶的影响,以期为葡萄生产实践中精准灌溉及施肥提供参考依据。结果表明:不同程度水分胁迫下施加硝酸钠对植株各部氮代谢相关酶活性影响较大,整体上随着水分胁迫程度的加深植株各部硝酸还原酶(NR)活性提前出现峰值,降低了谷氨酰胺合成酶(GS)和谷氨酸合成酶(GOGAT)活性,提高了谷草转氨酶(GOT)和谷丙转氨酶(GPT)活性,且提前出现峰值;轻度水分胁迫一定程度上加强了植株氮代谢相关酶活性。综上,不同水分胁迫处理下施加硝态氮后对"维多利亚"葡萄幼苗各部氮代谢相关酶的活性影响较大;轻度水分胁迫一定程度上加强了植株各部氮代谢相关酶活性;随着水分胁迫程度加深植株各部NR活性响应提前,GS和GOGAT活性降低,GOT和GPT活性响应提前,从而影响了植株氮代谢过程。

Annual grape variety（Vitis vinifera L.Victoria）seedlings were used as experimental materials.The effects of sodium nitrate on enzymes related to nitrogen metabolism in grape seedling under water stress were studied.Hydroponic culture techniques were used to simulate different water stress levels with concentrations of 5%,10%,15% PEG-6000,in order to provide important theoretical basis for precision irrigation and fertilization in production practice on grapes.The results showed that different water stress exerted great influence on sodium nitrate nitrogen metabolism related enzymes in different plant parts of the whole,with the deepening of water stress in different plant parts,the nitrate reductase（NR）activity appeared peak in advanced,reduced glutamine synthetase（GS）and glutamate synthase（GOGAT）activity,increased glutamic oxaloacetic transaminase（GOT）and glutamic-pyruvic transaminase（GPT）activity and had early peak;mild water stress to some extent strengthened the activity of enzymes related to nitrogen metabolism.In conclusion,under different water stress under nitrate applied could impact on nitrogen metabolism related enzyme activity greatly in Victoria grape seedlings;mild water stress to some extent strengthened the other parts of the plant nitrogen metabolism related enzyme activity;with the deepening degree of water stress in different plant parts of NR activity in response to advance,decreased the activities of GS and GOGAT,the activities of GOT and GPT responsed in advance,thus affecting the nitrogen metabolism process.