Research Of Hsp70 Genes Cloning And Expression In The Plutella Xylostella (L.)

Plutella xylostella (Lepidoptera:Plutellidae) is the migratory pest worldwide. It mainly damages cauliflower, cabbage and other cruciferous crops. HSP70 family has many important biological functions; it is important implications to research to protective effect of the cells, thermotolerance and anti-apoptotic under stress conditions. This paper on the basis of previous studies of the laboratory, By RACE technology, cloned a full-length hsp70 of 2152bp containing a 1890bp open reading frame that encoded 629 amino acids. The length of 5 ’UTR is 96bp, while the length of 3’UTR is 167bp. The deduced protein had a molecular weight of 69.10 kDa. Px-hsp70 belonged to the hsp70 family through the NCBI sequence alignment and functional sites analysis. The phylogenetic tree was created from the alignments of the amino acid sequences, and the analysis revealed that Px-HSP70 was nearly 91% identical to HSP70 from Bombyx mori (B.mori) and Spodoptera exigua (S.exiqua).The HSP70 family contained 3 highly conserved polypeptides:IDLGTTYS, IFDLGGGTFDVSIL and VVLVGGSTRIPKIQT, with the location site 6-13,194-207 and 332-346, respectively.HSP70 family can play the role of molecular chaperons. HSP70 are expressed for the heat stress tolerance and promote cell survival. HSP70 also participate in the anti-apoptotic. The expression of Px-hsp70 under heat stress (37,42℃) was studied. The results showed that the expression level of hsp70 increased significantly when the adult of DMB were pretreated with high temperature. And the extent of up-regulation (compared to 25℃) at 42℃ was significantly higher than that at 37℃. The results indicated that hsp70 could protect DMB from heat stress.