GmRACK1基因对大豆耐旱性调控作用研究

GmRACK1 Gene Negatively Regulates Drought-Tolerance in Soybean

活化C激酶1受体(RACK1)属于含有色氨酸-天冬氨酸结构域(WD)重复结构的蛋白质亚家族。为研究GmRACK1在干旱胁迫中的调控作用,本研究构建GmRACK1基因过表达与沉默两种双元表达载体并转化大豆,对转基因和对照大豆株系进行干旱和复水处理,测定株系的干重、存活率、叶绿素含量、过氧化氢含量和抗氧化酶活性等指标;分析GmRACK1基因对大豆抗旱性的调控作用。结果显示:在干旱胁迫下,大豆GmRACK1基因沉默株系(RNAi)的存活率和干重明显高于野生型(WT)和过表达(OE)株系。干旱10 d后RNAi株系的叶绿素含量显著高于WT和OE株系,OE株系的DAB和NBT染色颜色比WT和RNAi株系深。土壤干旱胁迫10 d后复水4 d,RNAi株系恢复好于WT和OE株系。在15%PEG 4000处理下,RNAi株系抗氧化物酶SOD、POD和CAT的活性和ABA含量显著高于WT和OE株系,而MDA和电导率显著低于WT和OE株系。结果说明RNAi株系能清除过多活性氧,导致植物的氧化伤害减弱。GmRACK1基因对大豆耐旱性存在调控作用。

Receptor of activated protein kinase C1(RACK1)belongs to a subfamily of proteins with a repeated structure of the tryptophan-aspartic acid domain(WD).In order to study the regulation of GmRACK1 in drought stress,we constructed overexpression and silencing two binary expression vectors of GmRACK1 gene and transformed into soybean.The control and transgenic lines were treated with drought and rewatering.The dry weight,survival rate,chlorophyll content,hydrogen peroxide content and antioxidant enzyme activity of the lines were measured.We analyzed the regulation of GmRACK1 gene on drought resistance of soybean.The results showed that,under drought stress,the survival rate and dry weight of GmRACK1 gene silenced lines(RNAi)were significantly higher than those of WT and OE lines.After 10 days drought,the chlorophyll content of RNAi lines was significantly higher than that of WT and OE lines.The color of the staining OE lines stained with DAB and NBT was deeper than that of WT and RNAi lines.After 10 days soil drought stress and then 4 days rewatering,RNAi lines recovered better than WT and OE lines.Under 15%PEG 4000 treatment,the activities of SOD,POD,CAT and ABA content of RNAi strains were significantly higher than those of WT and OE strains,while MDA and conductivity were significantly lower than those of WT and OE strains.These results indicated that RNAi strain could remove excessive reactive oxygen species,which will weaken the oxidative damage to plants,so the GmRACK1 gene could regulate the drought tolerance of soybean.