取食不同牧草对亚洲小车蝗发育速率和类胰岛素信号通路的影响

Effects of feeding different plant species on the phenotype and insulin-like signaling pathway of Oedaleus asiaticus

亚洲小车蝗是重要的草地生物灾害,对不同牧草的食物适应存在差异。为揭示不同牧草对亚洲小车蝗生长发育的影响机理,本研究定量分析了取食不同牧草条件下亚洲小车蝗的发育速率和类胰岛素信号通路(ISP)基因表达。结果表明,西北针茅饲喂的亚洲小车蝗发育速率最高,ISP通路中gIGF1、gINSR、gIRS1、gPI3K、gAKT及gmTor基因表达显著上调(P<0.05),调控下游发育和代谢相关的表皮蛋白(cuticle protein,gLCP)、胰凝乳蛋白酶(chymotrypsin,gCHY)及α-葡萄糖苷酶(α-glucosidase,gALP)基因表达上调。相反,冷蒿饲喂的蝗虫发育速率显著降低(P<0.05),上述基因显著下调(P<0.05),调控下游解毒相关的gP450s 6K1、gUDP 2C1及gCarE基因表达上调。亚洲小车蝗ISP通路响应食物差异,调控发育速率,以适应更广泛的生态区域,这可能是其分布广、易暴发成灾的原因之一。

Oedaleus asiaticus Bey-Bienko,a grasshopper pest occurring in North China,has evolved a food-specific adaptation to different plants.In this study,we analyzed the growth rate and gene expression of insulin-like signaling pathway(ISP)in O.asiaticus with different plant species.The results showed that the growth rate of O.asiaticus was significantly increased(P<0.05)when presented with Stipa sareptana var.krylovii.The expressions of gIGF1,gINSR,gIRS1,gPI3K,gAKT,gmTor in the ISP pathway were significantly up-regulated(P<0.05).The downstream genes gLCP,gCHY and gALP were also significantly up-regulated(P<0.05).In contrast,the growth rate of grasshoppers feeding on Artemisia frigida and the gene expression in the ISP pathway were significantly decreased(P<0.05),while the downstream genes gP450s 6K1,gUDP 2C1,gCarE were significantly up-regulated(P<0.05).These results suggested that O.asiaticus has evolved an active mechanism using ISP pathway to regulate its growth rate and adapt to wider ecological area comprising different plant species.This explains why O.asiaticus is the most widely distributed and easy-to-outbreak species in Inner Mongolia,China.