氮素形态对冬小麦旗叶GS及其同工酶活性和籽粒蛋白质含量的影响

Effects of Nitrogen Forms on the Activities of GS,GS Isozyme in Flag Leaf and Protein Content of Kernel in Winter Wheat

为探明氮素形态对小麦品质形成的作用,以强筋小麦品种豫麦34为材料,通过盆栽试验,研究了酰氨态氮、铵态氮、硝态氮3种氮形态下,小麦花后旗叶谷氨酰胺合成酶(GS)和同工酶活性、籽粒蛋白质及蛋白组分含量的变化及其关系。结果表明,在小麦开花后,GS及其同工酶活性在不同时期受不同氮素形态的影响;GS同工酶在3种氮素形态处理下均呈现三条酶带,分别为GS1、GS2、GSx;铵态氮促进了灌浆前期GS的活性,并提高了GS2活性,酰氨态氮对GS1活性具有促进作用;GS活性受GS2活性的影响较大。不同氮形态对籽粒蛋白含量的影响表现为铵态氮提高了籽粒形成初期蛋白质的含量,酰氨态氮有利于后期蛋白质含量的提高。籽粒蛋白质组分对氮形态的反应不一致。同时,籽粒蛋白的合成与GS及GS同工酶活性相关。在生产上可以通过不同形态的氮源配合使用,调控小麦籽粒蛋白质的含量和各蛋白组分的形成。

Pot experiments utilizing a sandy loam soil and high gluten wheat cultivar ＂Yumai 34＂ were completed during 2006-2008 to elucidate the effect of nitrogen forms on wheat nutrition quality and find the application method of nitrogen for the high gluten wheat production.Nitrogen forms were NH2——N（urea）,NH4＋-N（NH4HCO3） and NO3——N（NaNO3）,and nitrification inhibitor dicyandiamide（DCD） was applied in NH2——N and NH4＋-N treatments.Spikes of wheat which flowered on the same day were marked and flag leaves and grains were sampled at fixed dates.Each sample weighed 1.000 g FW and was stored at-70℃.The activities of GS and GS isozyme in flag leaves,the content of protein and protein components in grain were analyzed.Linear regression analysis was used to study the relationship between the activities of GS,GS isozyme and protein synthesis of kernel.This study showed that the activities of GS and GS isozyme in flag leaves,the content of protein and protein components in grain responded differently to nitrogen forms after anthesis.There were 3 isozyme bands under all nitrogen forms.The activity of GS1 was induced by NH2——N.However,NH4＋-N promoted that of GS2.The activity of GS was affected by GS2.Protein content was increased by NH4＋-N in the initial stage of grain filling,but in the later stage,it was enhanced by NH2-N.There was correlation between protein synthesis of kernel with activities of GS and GS isozyme in flag leaf.We recommended match usage of NH2——N and NH4＋-N mixed with DCD for the high gluten wheat production.