Molecular Cloning,Expression Patterning And Functional Analysis Of The Cbp And Hunchback Genes In The Diamondback Moth,Plutella Xylostella(L.)

The diamondback moth(DBM),Plutella xylostella(L.)(Lepidoptera: Plutellidae)is the most destructive insect pest of the cruciferous crops throughout the world.Different insecticides have long been applied to suppress its outbreak all these years.However,DBM can evolve resistance to almost any insecticide within a comparatively short period.New strategies are urgently necessitated for DBM control.Transcription factors(TFs)have high potentials in pest control especially the pupal specific gene br(Broad-complex)in holometamorphic insects.It is generally thought that expression of br is coregulated by juvenile hormone and ecdysone.However,whether there are any other regulation factors are still unclear.After successful cloning of the open reading frames(ORFs)of hunchback and CREB-binding protein gene(cbp),their expression patterning at different life stages in DBM was investigated by means of quantitatively real-time PCR(q PCR)method.The regulation role of hunchback on br was confirmed by soaking the eggs into ds RNA solution of hunchback to find out the changes in br expression.The effect of cbp on br expression was studied by treating the 3rd instrar larvae of DBM with ICG 001,inhibitor of CBP,through leaf-dipping method to find out the changes in the growth and development of tested insects and that in of br expression in them.The results indicated that,the lenghs of ORFs of hunchback and cbp were 1866 and 3612 bp,respectivley,the highest expression of hunchback occurred in egg stage but that of cbp was in adult stage,the expression of hunchback was decreased,but that of br increased in eggs soakd in the ds RNA solution for 16 h,and in the 4th instar larvae of tested insects,the expression of br decreased,the pupation delayed and the pupation rate lowered after feeding the 3rd instar larvae of DBM with ICG 001.The results suggest that at least in the egg stage of DBM,hunchback decreases the expression of br but in the later instar larave,cbp increases that.These shall help to make a better understanding of the underlying regulation mechanism of br expression in DBM and provide evidence for developing new measures for DBM control based on br disruption.