重度干旱胁迫下草甘膦对转基因大豆生理特性及光系统Ⅱ蛋白表达的影响

Effect of Severe Drought and Glyphosate Stress on Physiological Characteristics and Protein Expression of Photosystem Ⅱ in Genetically Modified Soybean

为探究重度干旱胁迫下草甘膦对转基因大豆幼苗生理特性及光系统Ⅱ(PSⅡ)蛋白表达的影响,以转基因大豆GTS 40-3-2为试验材料,采用盆栽试验,在GTS 40-3-2幼苗第三复叶期进行重度干旱胁迫和喷施不同浓度草甘膦的处理。生理指标检测结果表明,重度干旱胁迫条件下,大豆叶片相对电导率(EL)、超氧化物歧化酶(SOD)、过氧化物酶(POD)活性均高于对照,其中EL、POD活性与对照差异显著;相对含水量(RWC)、叶绿素含量、过氧化氢酶(CAT)活性均低于对照,其中RWC、CAT活性与对照差异显著。重度干旱及草甘膦双重胁迫条件下,EL、SOD、POD活性均高于对照,且随着草甘膦浓度的升高而升高;叶绿素含量低于对照,且随着草甘膦浓度升高而降低;RWC、CAT活性不受草甘膦浓度影响。Western blot杂交试验结果表明,PSⅡ蛋白Lhcb2稳定表达,不受胁迫条件影响。重度干旱胁迫条件下,与对照相比,Lhcb1表达量无明显变化;D1、D2、Lhcb4表达量均出现不同程度的降低。重度干旱及草甘膦双重胁迫条件下,D1、D2、Lhcb1、Lhcb4表达量均随着草甘膦浓度上升呈下降趋势,草甘膦浓度为0.92和1.84 kg·ai·hm^(-2)时,D1、D2、Lhcb4表达量均略高于重度干旱胁迫;草甘膦浓度为3.68和7.36 kg·ai·hm^(-2)时,D1、D2、Lhcb1、Lhcb4表达量急剧下降。本研究结果为转基因大豆生产提供了理论依据。

This study was conducted to investigate effects of glyphosate stress on physiological characteristics and photosystem Ⅱ（ PSII） protein level in genetically modified soybean GTS 40-3-2 seedlings under severe drought condition. To achieve this objective,a pot experiment was carried out in growth chamber to determine the response of V3 stage of genetically modified soybean treated with severe drought stress and different concentrations of glyphosate. Severe drought treatment increased the Electrolyte leakage（ EL）,Superoxide dismutase（ SOD） and Peroxidase（ POD）activities,and decreased relative water content（ RWC）,chlorophyll content,and Catalase（ CAT） activity. The EL,SOD and POD activities were significantly increased under severe drought and glyphosate treatments,which were related to glyphosate concentrations. The chlorophyll content was decreased, which was also related to glyphosate concentrations. But the RWC and CAT activity were not affected by glyphosate concentrations. Western blot displayed PSⅡ protein Lhcb2 was not affected by stress conditions and stably expressed. D1,D2 and Lhcb4 protein level decreased,and there was no significant change of Lhcb1 expression under severe drought stress. The protein level of D1,D2,Lhcb1 and Lhcb4 decreased with glyphosate concentrations under severe drought and glyphosate stress. When the glyphosate concentrations were 0. 92 and 1. 84 kg. ai. hm^-2,the protein level of D1,D2 and Lhcb4 were slightly higher than those in severe drought stress. When the glyphosate concentrations were 3. 68 and 7. 36 kg. ai. hm^-2,the protein level of D1,D2,Lhcb1 and Lhcb4 decreased sharply. This research provides theoretical basis for cultivation of genetically modified soybean.