转cry1Ab基因水稻中毒蛋白的表达、分泌及其在土壤中的残留

研究了转cry1Ab基因水稻(克螟稻)中Cry1Ab毒蛋白的表达、根系分泌及其在土壤中的残留规律.结果表明,分蘖始期至成熟期,克螟稻地上部和根部中的Cry1Ab毒蛋白的表达量(FW)分别为3.23～8.22 μg/g和0.68～0.89 μg/g.生育期间克螟稻根系分泌的Cry1Ab毒蛋白含量仅为1.66～48.02 ng/(株·d).试验证实,克螟稻根际土中的Cry1Ab毒蛋白残留含量低于检测限(<0.5ng/g 干燥土).生物测定还表明,克螟稻根际土及其提取液对棉铃虫初孵幼虫和3龄幼虫不产生致死性效应.相对于Cry1Ab毒蛋白的根系分泌转移,克螟稻秸秆还田对土壤环境的影响应引起重视.

Expression and Root Exudation of Cry1Ab Toxin Protein in cry1Ab Transgenic Rice and Its Residue in Rhizosphere Soil

The expression and root exudation of Cry1Ab toxin protein in cry1Ab transgenic rice (KMD) and its residue in rhizosphere soil were investigated. The results showed that content of Cry1Ab toxin protein in the shoot and root of KMD were 3.23-8.22 and 0.68-0.89 microg/g from early tillering to maturing stage, respectively. The content of the Cry1Ab toxin proteins via root exudation were 1.66-48.02 ng/(individual x d) at that phase. The results also demonstrated that the residue of the Cry1Ab toxin protein in rhizosphere soil was less than detectable level (0.5 ng/g air-dried soil). In addition, insecticidal bioassay indicated that rhizosphere soil and its extraction solution had no significant effect on mortality of first- and third-instar larvae of cotton bollworm (Heliochis armigera). It suggested that the KMD straws returned to the field might have the higher potential environmental risk than the root exudation.