Abstract: To investigate whether the heat shock gene 70 (Hsp70) in Bemisia tabaci B-biotype and Trialeurodes vaporariorum has different expression profile in response to temperature stress, the full length cDNA of the Hsp70in the two whitefly species was cloned, and the expression profile of the Hsp70 across a temperature gradient was analyzed by real-time quantitative PCR. The Hsp70gene of both B. tabaci B-biotype and T. vaporariorum, named BTHsp70 and TVHsp70 (GenBank accession nos: DQ093385 and EU861391, respectively), had TATA-box-like elements in 5’-UTR, poly(A) signals AATAA in 3’-UTR, and three highly conserved functional motifs of the Hsp70 protein family in deduced amino acid sequences. Across the temperature gradient (from -19 to 46 ℃), the onset temperature (T_on) or maximal temperature (T_max) for inducing Hsp70 expression in T. vaporariorumwas 2.5 ℃-7.5 ℃ lower than those for the expression in B. tabaci B-biotype. All the results revealed that the cloned genes were of inducible Hsp70 gene, and, in terms of gene expression level, T. vaporariorum was more cold-tolerant than B. tabaci B-biotype, while the latter was more heat-tolerant. The T_on (or T_max) of the Hsps could represent the differences in temperature tolerance of these two whitefly species. To some extent, our results explained the different geographical distribution and seasonal occurrence of the two whitefly populations in nature.

Key words: Monopterus albus, Ecological factors, Oosperm, Hatching rate