论文部分内容阅读
在室内选用Cry1Ac对小菜蛾Plutella xylostella 3龄幼虫进行抗性选育,获得相对抗性为356倍的抗性种群DBM1Ac-R品系。应用实时定量基因扩增荧光检测(real time quantitative PCR,real-time qPCR)技术检测敏感小菜蛾DBM1Ac-S和抗性小菜蛾DBM1Ac-R品系鞘糖脂(Glycosphingolipids,GSLs)合成酶基因bre-3和bre-5 mRNA在2龄、3龄、4龄和老熟幼虫、蛹及4龄中肠的表达情况。结果显示:bre-3和bre-5在两个品系的5个时期和4龄中肠均有表达,其中DBM1Ac-S品系的bre-3 mRNA在3龄、4龄和老熟幼虫的相对表达量显著高于DBM1Ac-R品系(P<0.05),分别为DBM1Ac-R品系的2.36、5.54和2.68倍;DBM1Ac-S品系的bre-5 mRNA在2龄至蛹期的相对表达量分别为DBM1Ac-R品系的1.19、3.13、1.78、1.75和1.65倍,其中由3龄到蛹期差异显著(P<0.05)。DBM1Ac-R品系3龄至老熟幼虫的bre-3和bre-5 mRNA相对表达量降低可能与小菜蛾长期的Cry1Ac汰选有一定的关系。比较同一种群、同一龄期(包括4龄中肠)的bre-3和bre-5 mRNA相对表达量差异时,发现bre-5相对表达量均高于bre-3。研究结果为苏云金芽孢杆菌(Bacillus thuringiensis,Bt)杀虫晶体蛋白受体之一GSLs的进一步研究提供了一定的基础。
Cry1Ac was used to screen the 3rd instar larvae of Plutella xylostella against DBM1Ac-R, a resistant strain with 356-fold relative resistance. Real time quantitative PCR (real-time qPCR) was used to detect the expression of the glycosphingolipids (GSLs) synthetase gene bre-3 in DBM1Ac-S and DBM1Ac-R resistant diamondback moth And bre-5 mRNA expression in 2nd, 3rd, 4th and mature larvae, pupae and 4th instar midgut. The results showed that bre-3 and bre-5 were expressed in 5 stages and 4-year-old midgut of both strains. The relative expression of bre-3 mRNA in DBM1Ac-S strain at 3, 4 and mature larvae (P <0.05), which were 2.36, 5.54 and 2.68 times higher than those of DBM1Ac-R strain respectively. The relative expression levels of bre-5 mRNA in DBM1Ac-S strain from 2 instars to pupal stages were DBM1Ac -R strains were 1.19, 3.13, 1.78, 1.75 and 1.65 times, respectively, from 3 to pupal stage (P <0.05). The relative expression of bre-3 and bre-5 mRNA in 3rd instar to mature larvae of DBM1Ac-R strain may be related to the long-term deletion of Cry1Ac in Plutella xylostella. When comparing the relative expression levels of bre-3 and bre-5 mRNA in the same age group, including the 4th instar midgut, the bre-5 relative expression level was higher than bre-3. The results provide a basis for further study of GSLs, one of the insecticidal crystal protein receptors of Bacillus thuringiensis (Bt).