低磷胁迫对转基因抗虫玉米苗期生长的影响

Effect of low phosphorus stress on insect-resistant maize at seedling stages

为了了解导入Bt基因是否会引起玉米对磷元素利用能力发生改变,本研究采用转基因抗虫玉米Bt 38及其背景材料郑单958(ZD 958)为试验材料,进行水培试验,设置正常供磷(1mmol/L)和低磷(1μmol/L)两个水平。结果表明:在相同磷浓度下,ZD 958与Bt 38的某些生物性状、生理性状显著地不同,在生物性状上,正常供磷条件下与ZD 958相比,Bt 38根长极显著降低,全展叶叶面积极显著减小,低磷条件下与ZD 958相比,Bt 38株高、根长、茎粗、叶长,叶宽、地上鲜重、地下鲜重均极显著增加,根冠比显著下降;在生理特征上,相同供磷条件下,与ZD 958相比,抗虫玉米心叶、全展叶叶绿素含量及Chla/Chlb均有显著性变化,抗虫玉米不同部位可溶性糖、淀粉含量、激素含量亦有显著性变化。此外,全展叶中可溶性蛋白含量和抗氧化物酶活性也有显著性变化。综上,Bt基因的导入改变了ZD 958苗期对磷元素的利用能力,从而使ZD 958与Bt 38在不同磷环境下表现出不同的生存能力。

In order to explore the difference of phosphorus(P)use efficiency between Bt corn and Non-Bt corn,we take Bt 38(Bt maize)and the background maize ZD 958(NON-Bt maize)as experimental materials,using hydroponics at two P concentration levels(1mmol/L,1μmol/L)to test the effect.The result showed that some biological traits and physical signs presented significant difference even under the same P concentrations between Bt 38and ZD 958.Among the biological traits,root length,full-developed leave area from Bt corn decreased markedly under normal P concentration compared with ZD 958.Furthermore,plant height,root length,Stem diameter,leaf length,leaf width,shoot fresh weight,root fresh weight all increased dramatically,while root/shoot ratio decreased significantly.Additionally, among physical signs,compared with Bt 38vs ZD 958,Chlorophyll content and Chla/Chlb of unfully-developed and fullydeveloped leaves,solvable sugars and starch content as well as plant hormone content among different part of maize changed markedly.Moreover,solvable proteins content,activities of anti-oxidant enzymes changed significantly under different P concentration treatments.In a word,expression of Cry1Ac affected both biological and physical traits in Bt corn,which lead to diverse viabilities under the same P concentrations.