低氮胁迫下外源色氨酸对小叶杨生长和氮代谢酶活性的影响  

Effects of Tryptophan on Growth and Nitrogen Metabolism Physiology of Populus simonii Under Low Nitrogen Stress

作　　者：郭晓霄 王小华 GUO Xiaoxiao;WANG Xiaohua(Shanxi Provincial Forestry Ecological Experimental Base,Taiyuan 030031,Shanxi,China)

机构地区：[1]山西省林业生态实验基地,山西太原030031

出　　处：《贵州林业科技》2024年第3期20-25,共6页Guizhou Forestry Science and Technology

基　　金：山西省科技厅专项项目(晋〔2021〕TG12)。

摘　　要：研究外源色氨酸对低氮下小叶杨生长和氮代谢的影响规律,可为生产中利用色氨酸缓解氮胁迫提供理论依据。以小叶杨扦插苗为试验材料,设置正常供氮(N1)、低氮(N2)、低氮+30 mg·L^(-1)色氨酸(N3)、低氮+65 mg·L^(-1)色氨酸(N4)、低氮+100 mg·L^(-1)色氨酸(N5)共5个处理,研究不同浓度色氨酸对低氮胁迫下小叶杨生长和氮代谢的影响。结果表明:低氮胁迫显著降低了小叶杨株高,与N4相比,N2、N3的株高分别提高了49.28%、28.16%,N5与N4对株高的影响处于同一水平;与N1相比N2会显著降低小叶杨硝酸还原酶、谷氨酰胺合成酶、谷氨酸合成酶、亚硝酸还原酶活性,与N2相比N4会显著提高各氮代谢酶活性,N2与N3处理各氮代谢酶活性处于同一水平,N4与N5之间无显著差异;低氮胁迫降低了小叶杨游离氨基酸含量,N4可显著提高低氮胁迫下小叶杨叶片内游离氨基酸含量。65 mg·L^(-1)的色氨酸是促进低氮胁迫下小叶杨生长和提高氮代谢能力的适宜浓度。Tryptophan can be expected to alleviate the nitrogen stress in tree production.This study aims to clarify the effects of exogenous tryptophan on the growth and nitrogen metabolism of Populus simonii under low nitrogen conditions.The Populus simonii cuttings were used as experimental materials.Five treatments were then set,including normal nitrogen supply(N1),low nitrogen(N2),low nitrogen+30 mg·L^(-1)tryptophan(N3),low nitrogen+65 mg·L^(-1)tryptophan(N4),and low nitrogen+100 mg·L^(-1)tryptophan(N5).A systematic investigation was made on the effects of different concentrations of tryptophan on the growth and nitrogen metabolism.The results show that the height of Populus simonii was significantly reduced under low nitrogen stress.The plant height of N4 was 49.28%and 28.16%higher than those of N2 and N3,respectively.There was the similar impact of N5 and N4 on the plant height;The activities of nitrate reductase,glutamine synthetase,glutamate synthetase and nitrite reductase in Populus simonii of N2 were significantly lower than those of N1.While the activities of various nitrogen metabolism enzymes of N4 were significantly higher than those of N2.The similar level was observed in the activities of nitrogen metabolism enzymes in the N2 and N3 treatments.There was no significant difference between N4 and N5;The low nitrogen stress was reduced the content of free amino acids in Populus simonii.But the N4 significantly increased the content of free amino acids in Populus simonii leaves under low nitrogen stress.Therefore,the 65 mg·L^(-1)of tryptophan was an appropriate concentration to promote the growth and nitrogen metabolism of Populus simonii under low nitrogen stress.

关 键 词：色氨酸 低氮胁迫 株高 氮代谢 小叶杨 

分 类 号：S723[农业科学—林木遗传育种] Q945[农业科学—林学]