不同小白菜品种硝酸盐含量、氮代谢关键酶活性及NRT1表达和亚细胞定位  

Nitrate Content, Activities of Key Enzymes for Nitrogen Metabolism, and Expression and Subcellular Localization of NRT1 in Different Nitrate-Enriched Varieties of Pakchoi(Brassica chinensis L.)

作　　者：李彦华[1] 杨芸[1] 徐卫红[1] 周鑫斌[1] 王卫中[1] 迟荪琳 李桃[1] 张春来[1] 赵婉伊[1] 秦余丽 王正银[1] 谢德体[1] LI Yanhua;YANG Yun;XU Weihong;ZHOU Xinbin;WANG Weizhong;CHI Sunlin;LI Tao;ZHANG Chunlai;ZHAO Wanyi;QIN Yuli;WANG Zhengyin;XIE Deti(College of Resources and Environment,Southwest University,Chongqing 400715,China)

机构地区：[1]西南大学资源环境学院,重庆400715

出　　处：《食品科学》2018年第7期78-84,共7页Food Science

基　　金：国家现代农业(大宗蔬菜)产业技术体系建设专项(CARS-23);"十一五"国家科技支撑计划项目(2007BAD87B10)

摘　　要：采用液体培养实验研究了不同硝铵比(NO_3^-∶c(NH_4^+)分别为50∶50、75∶25和100∶0)对低硝酸盐富集品种‘香港特选奶白菜’和高硝酸盐富集品种‘揭农四号春白菜’硝酸盐含量、氮代谢关键酶活性的影响,并探讨了两个品种小白菜硝酸盐转运蛋白基因的表达和亚细胞定位。结果表明:‘香港特选奶白菜’和‘揭农四号春白菜’在硝铵比100∶0处理中,叶硝酸盐含量分别较硝铵比50∶50处理增加了13.2%和30.4%,叶柄硝酸盐含量增加了14.3%和4.9%。随着硝铵比的增加,小白菜叶片硝酸还原酶、谷氨酸合成酶活力呈降低趋势,亚硝酸还原酶活力呈上升趋势,谷氨酸脱氢酶活力呈先增加后降低趋势,且两个小白菜品种之间差异显著。低亲和硝酸盐转运蛋白(nitrate transporter,NRT)1基因NRT1在两个小白菜品种中均显著表达,且高富集硝酸盐品种"揭农四号春白菜"的表达量显著高于低富集硝酸盐品种‘香港特选奶白菜’的表达量。NRT1是一个定位于细胞膜上的低亲和NRT。Solution culture experiments were conducted to investigate the effect of nitrate/ammonium ratio(50:50,75:25 and 100:0)on nitrate content,the activities of key enzymes for nitrogen metabolism in pakchoi,and the expression and subcellular localization of nitrate transporter gene in two pakchoi varieties(low-nitrate variety‘JN4’and high-nitrate variety‘HKTX’).The results showed that nitrate contents in leaves of‘HKTX’and JN4 subjected to treatment at NO3-/NH4+ratio of 100:0 increased respectively by 13.2%and 30.4%compared with treatment at NO3-/NH4+ratio of 150:50;nitrate contents in petioles of‘HKTX’and‘JN4’were increased respectively by 14.3%and 4.9%compared with treatment at NO3-/NH4+ratio of 50:50.With the increase of NO3-/NH4+ratio,the activities of nitrate reductase(NR)and glutamate synthase(GOGAT)in pakchoi decreased,the activity of nitrite reductase(NiR)increased,and the activity of glutamate dehydrogenase(GDH)initially increased and then decreased.Significant differences in NR,GOGAT,NiR,and GDH were observed between the two varieties.Significant expression of low affinity transporter gene(NRT1)was detected in both varieties,and a higher expression level was observed in‘JN4’than in‘HKTX’.NRT1 was a low affinity nitrate transporter located in the plant cell membrane.

关 键 词：硝铵比 硝酸盐含量 氮代谢关键酶 硝酸盐转运蛋白基因 亚细胞定位 小白菜 

分 类 号：S634.3[农业科学—蔬菜学]