论文部分内容阅读
为明确植物源活性物质姜黄素对朱砂叶螨Tetranychus cinnabarinus的杀螨作用机理,克隆并分析了6条朱砂叶螨几丁质酶基因(Tc CHTs)的c DNA序列,利用RT-q PCR技术,测定了不同发育阶段的螨体内几丁质酶基因表达的情况,同时研究了姜黄素作用下几丁质酶基因表达的变化。结果表明:6条几丁质酶基因(Tc CHIT1、Tc CHIT2、Tc CHIT3、Tc CHT4、Tc CHT5和Tc CHT6)有不同的结构域,预测其蛋白质分子质量分别为60.80、69.03、104.32、59.75、45.63和49.05 k Da,等电点分别为5.44、8.65、6.23、6.07、6.12和8.27。6条基因的表达量均为幼螨和若螨时期显著高于卵和成螨时期。不同浓度姜黄素处理朱砂叶螨若螨24 h后,6条基因的表达量均有不同程度下调,其中Tc CHIT1和Tc CHT5的下调更为显著。研究结果表明,姜黄素对朱砂叶螨的杀螨作用机制之一可能是通过抑制几丁质酶的活性,进而影响几丁质的降解过程,最终因螨体壁受损而导致螨不能正常生长发育。
To clarify the mechanism of acaricidal action of plant-derived active curcumin on Tetranychus cinnabarinus, the c DNA sequences of six Trichosanthes cinnabarinus chitinase genes (Tc CHTs) were cloned and analyzed. RT- The expression of chitinase gene in mite body at different developmental stages was determined. The chitin gene expression was also studied under the action of curcumin. The results showed that the six chitinase genes (Tc CHIT1, Tc CHIT2, Tc CHIT3, Tc CHT4, Tc CHT5 and Tc CHT6) have different domains. The predicted molecular mass of the six chitinase genes are 60.80, 69.03, 104.32 and 59.75, 45.63 and 49.05 kDa respectively. The isoelectric point of 5.44, 8.65, 6.23, 6.07, 6.12 and 8.27.6 genes were all significantly higher in the larvae and nymphs than in the eggs and adult mites. After treated with curcumin for 24 h, the expression of 6 genes was down-regulated to some extent, of which the down-regulation of Tc CHIT1 and Tc CHT5 was more significant. The results showed that one of the mechanisms by which curcumin may have an acaricidal effect on T. cinnabarinus may be that it inhibits the activity of chitinase and further affects the degradation process of chitin. Finally, the mite can not grow normally due to the damaged mite wall development.