镉对超富集植物圆锥南芥氮素代谢的影响研究  

EFFECTS OF CADMIUM ON ACTIVITIES OF KEY NITROGEN METABOLISM ENZYMES IN LEAVES OF ARABIS PANICULATA FRANCH

作　　者：于方明[1] 仇荣亮[1] 周小勇[1] 应蓉蓉[1] 汤叶涛[1] 赵璇[1] 胡鹏杰[1] 曾晓雯[1] 

机构地区：[1]中山大学环境科学与工程学院,广州510275

出　　处：《土壤学报》2008年第3期497-502,共6页Acta Pedologica Sinica

基　　金：国家自然科学基金项目(40571144);广东省自然科学基金重点项目(05101824);广东省自然科学基金团队项目(06202438);教育部“新世纪优秀人才支持计划”项目(NCET-04-0790);985二期“环境与污染控制技术创新平台”项目资助

摘　　要：采用土培方法，研究了不同Cd添加（0、10、20、40、80、160和240mg kg^-1）对超富集植物圆锥南芥叶片中氮素含量以及氮代谢关键酶活性的影响。结果表明，随着Cd添加浓度的增加，圆锥南芥的生物量、叶片数、直径长以及Cd含量均呈增加趋势。Cd添加浓度为240mgkg^-1时，生物量增加了137％，叶片数增加了1．02倍，直径较对照增加了130％，叶片中Cd含量达到451mgkg^-1. NO^3- -N和NH4^＋ -N呈先降低后升高的变化趋势，在Cd浓度为240mgkg^-1时，达最大值。在Cd处理浓度为10、20、40 、80mgkg^-1时，NO3^＋ -N和NH4^＋ -N含量间无显著性差异（P〉0．05）。在Cd添加浓度为240mgkg^-1时，硝酸还原酶（NR）活性只相当于对照的67％，与对照间的差异显著。在Cd处理浓度为10—160mgkg^-1时，NR活性与对照间无显著性差异（P〉0．05）。谷氨酰胺合成酶（GS）、谷氨酸合酶（GOGAT）活性以及可溶性蛋白质含量在Cd处理浓度为10-240mgkg^-1时，与对照间无显著性差异（P〉0．05）。谷氨酸脱氢酶（GDH）活性呈先升高后降低的变化趋势。游离脯氨酸含量在Cd浓度为10、20、40、80、160、240mgkg^-1时，分别为对照的0．67倍、1．29倍、1．54倍、2．38倍、2．54倍、1.14倍。Effects of cadmium （Cd） on activities of key nitrogen metabolism enzymes in leaves of Arabis paniculata F. were studied. Arabis paniculata F., a newly identified hyperaccumulator, was grown in soils varying in Cd content （0, 10, 20, 40, 80, 160 and 240 mg kg^-1） for 135 days. Plants were analyzed for contents of NO3^- -N, NH4^＋ -N, soluble protein, proline and activities of nitrate reductase （NR）, glutamine synthetase （GS）, glutamate synthase （GOGAT）, glutamate dehydrogenase （GDH）. Results show that the biomass of Arabis paniculata F. increased with the Cd concentration in the soil and reached the highest in the treatment of 240 mg kg^- 1. In the treatments with Cd content varying from 10 to 80 mg kg^- 1, the contents of NO3^- - N and NH4^＋ -N in plant shoots were lower than in the control but did not show any significant variance （p 〉 0.05）, while in the treatments above 80 mg kg^-1 Cd, both the contents of NO3^- -N and NH4^＋ -N increased with the Cd concentration. Compared with the control, the treatments of Cd varying between 10 - 160 mg kg^- 1 did not show any significant variance （p 〉 0.05） in NR activity, but NR activity reduced sharply to 67% of the control in Treatment 240 mg kg^-1 Cd. Furthermore, the activities of GS, GOGAT and soluble protein in all the Cd treatments showed no significant variance （p 〉 0.05） from the control. The GDH activity increased with the Cd concentration from 10 to 80 mg kg^-1 and then decreased dramatically when above 80 mg kg^-1. Compared with that of the control, the contents of free proline increased obviously in the Cd treatments except in treatment 10 mg kg^-1 Cd.

关 键 词：镉 圆锥南芥 氮代谢 酶活性 

分 类 号：Q946.5[生物学—植物学]