Expression and synergistic activity of enhancin from Pseudaletia unipuncta granulovirus-Ps in Bacillus thuringiensis

Abstract:

[Objective] To express the truncated fragments of enhancin gene from Pseudaletia unipuncta granulovirus-Ps (PuGV-Ps) in Bacillus thuringiensis (Bt) and provide a theoretical basis for the construction of Bt engineering bacteria. [Methods] The codon of the truncated fragments of enhancin gene was optimized for the construction of the expression vectors of enhancin and the expression of fusion proteins. Then, the expression levels of enhancin under the guidance of two promoters were analyzed, and the synergistic activity of enhancin on Bt was determined. [Results] The expression vectors pHTP_cry1AcCoEn81, pHTRHCoEn81, and pHTNCCoEn81 were constructed in the study. SDS-PAGE showed that pHTP_cry1AcCoEn81 and pHTNCCoEn81 produced recombinant proteins of 81 kDa and 134 kDa, respectively. There was no significant difference in the expression level of enhancin or the yield of recombinant protein under the guidance of promoters P_cry1Ac and P_cry8E. Furthermore, the recombinant enhancin significantly increased the insecticidal activity of Bt against Plutella xylostella. [Conclusion] The codon-optimized enhancin of PuGV-Ps can be expressed in Bt and has significant synergistic activity, which provides theoretical guidance for the construction and application of Bt engineering bacteria with high efficiency.