不同形态氮素对专用型小麦花后氮代谢关键酶活性及籽粒蛋白质含量的影响  

Effects of different nitrogen forms on key enzyme activity involved in nitrogen metabolism and grain protein content in speciality wheat cultivars

作　　者：王小纯[1] 熊淑萍[1] 马新明[1] 张娟娟[1] 王志强[2] 

机构地区：[1]河南农业大学农学院,郑州450002 [2]武汉大学生命科学学院,武汉430072

出　　处：《生态学报》2005年第4期802-807,共6页Acta Ecologica Sinica

基　　金：河南省高校杰出科技人才创新工程基金资助项目 (2 0 0 2 KJCX0 5 ) ;教育部博士点基金资助项目 (2 0 0 40 4660 0 3 )~~

摘　　要：采用盆栽方法研究了氮素形态对不同专用型小麦开花后氮素同化关键酶活性及籽粒蛋白质含量的影响。结果表明:不同专用型小麦氮素同化关键酶硝酸还原酶、谷氨酰胺合成酶和谷氨酸合酶对氮素形态的反应不同。强筋小麦豫麦34施用酰胺态氮对旗叶硝酸还原酶和谷氨酰胺合成酶活性、籽粒谷氨酰胺合成酶和谷氨酸合酶活性具有明显的促进作用,最终籽粒蛋白质含量较高;中筋小麦豫麦4 9在施用铵态氮时,3种氮素同化关键酶活性均有较大增强,籽粒蛋白质含量最高;弱筋小麦豫麦5 0硝酸还原酶活性以铵态氮处理最高,而籽粒和旗叶谷氨酰胺合成酶和谷氨酸合酶活性在酰胺态氮处理下明显增强,酰胺态氮对籽粒中蛋白质含量的增加具有明显的促进作用。相关性分析表明,籽粒蛋白质含量与旗叶GS活性和籽粒GOGAT活性呈显著或极显著正相关,与旗叶NR活性和GS活性。In order to understand the effects of nitrogen form on key enzyme activity involved in nitrogen metabolism and grain protein content of speciality wheat cultivars, pot experiments were carried out at experimental station of Henan Agricultural University during 2000～2002. Soil containing 9.8 g/kg organic matter, 0.986 g/kg total N, 25.43 mg/kg olsen-p and 259 mg/kg NH_4OAc-K was used in the experiments. 18kg of sieved soil was placed in each 30cm×40cm pot. Three cultivars were used in experiments including Yumai34 (a strong gluten cultivar), Yumai49 (medium gluten) and Yumai50 (weak gluten). Nitrogen forms studied were NO~^-__3-N (NaNO_3), NH_4-N (NH_4HCO_3) and CONH_4-N (urea). Prior to sowing, 3.5 g N, 3.3 g K_2O and 2.9 g P_2O_5 per pot were applied and 1.6 g N was applied to each pot during the elongation stage. Seven plants from each pot were selected when plants had five leaves. The experiment was arranged in a completely random design with eight replications and all pots were managed in the same way. The NR activity of flag leaves from main stems were measured at 10、15、20、25 and 30days after flowering using the method of living body. GS and GOGAT in grains and flag leaves were extracted in the 100mmol/L Tris-HCl (pH 7.6) extraction buffer containing 1.0mmol/L EDTA, 1.0mmol/L MgCl_2·6H_2O and 10mmol/L 2-mercaptoethanol, and were used for the assay of enzyme activity. The synthetase activity of GS in extracts was determined in a reaction mixture containing imidazole-muriatic acid buffer (0.25mol/L, pH 7.0) 0.6ml,glutamic acid-Na (0.30mol/L, pH 7.0) 0.4ml,ATP-Na(30 mmol/L, pH 7.0) 0.4ml,MgSO_4 (0.5mol/L) 0.2ml and crude GS solution 1.2ml, after the mixture was incubated at 37℃ for 15min, the reaction was terminated by adding acidic FeCl_3 (2%(W/V) TCA and 3.5% (W/V) FeCl_3 in 2% HCl). Production of γ-glutamylhydroxamate was measured with a spectrophotometer at 540nm. One unit of GS activity was the enzyme catalyzing the formation of 1μmol γ-glutamylhydroxamate/min at 37℃, the whole GS

关 键 词：氮素形态 专用小麦 硝酸还原酶 谷氨酰胺合成酶 谷氨酸合酶 蛋白质含量 

分 类 号：S512.1[农业科学—作物学]