Abstract
BackgroundRNA interference (RNAi) technology shows a great potential in controlling agricultural pests, despite the difficulty of introducing exogenous dsRNA/siRNA into target pests. Isaria fumosorosea is a common fungal pathogen of the B-biotype Bemisia tabaci (whitefly), which is a widespread pest. Entomopathogenic fungi directly penetrate the cuticle and invade insect hemocoel. Application of I. fumosorosea expressing dsRNA of whitefly immunity-related gene may aid in developing RNAi technology to effectively control whiteflies.MethodsA dsRNA expression plasmid, psTLR7, was constructed by introducing the Toll-like receptor 7 (TLR7) gene of B-biotype whitefly to the silent vector, pSilent-1. The plasmid psTLR7 was transferred into the protoplast of the I. fumosorosea strain IfB01. Then, the recombinant strain was screened out based on the biological stability and bioactivity against whitefly.ResultsA genetically stable recombinant strain IfB01-TRL7 was screened out. The impact of IfB01-TRL7 against whitefly TRL7 gene was validated by qPCR. Lower expression levels of the TLR7 gene was observed in the whiteflies infected by the recombinant strain. The bioassay results indicated that compared to IfB01 strain, IfB01-TRL7 increased the mortality of whitefly nymphs, and decreased and shortened the values of LC50 and LT50, thus indicating higher virulence of IfB01-TRL7.ConclusionThe expression of the dsRNA of whitefly TLR7 gene in recombinant I. fumosorosea strain successfully knocked down the host target gene by infecting the nymphs and enhanced the whiteflies mortality. The present study will give insight to new application of RNAi technology for more effective biocontrol of this pests.Electronic supplementary materialThe online version of this article (doi:10.1186/s12896-015-0170-8) contains supplementary material, which is available to authorized users.
Highlights
Ribonucleic acid (RNA) interference (RNAi) technology shows a great potential in controlling agricultural pests, despite the difficulty of introducing exogenous Double-stranded ribonucleic Acid (dsRNA)/Small interfering RNA (siRNA) into target pests
The injection of dsRNA molecules into the body cavity of whiteflies caused 70 % reduction in the gene expression levels as compared to the whiteflies injected with buffer or with a green fluorescent protein (GFP)-specific dsRNA [10]
The contact treatments failed to deliver any impact (Hu et al, unpublished data). These findings suggest that RNA interference (RNAi) technology can be further developed to control the spread of whiteflies
Summary
RNA interference (RNAi) technology shows a great potential in controlling agricultural pests, despite the difficulty of introducing exogenous dsRNA/siRNA into target pests. Application of I. fumosorosea expressing dsRNA of whitefly immunity-related gene may aid in developing RNAi technology to effectively control whiteflies. Transgenic tobacco lines were developed for the expression of long dsRNA precursors of siRNA and for knocking down the V-ATPase A mRNA in whiteflies When these pests fed on the transgenic plants, their transcript level of V-ATPase A was reduced down to 62 % [12]. The dsRNAs of five genes (TLR7, GNBP1, integrin alpha-PS1-like isoform 3, C-type lectin-like precursor and phenoloxidase subunit A3-like) related to innate immunity were delivered into whitefly adults through oral and contact treatments. The contact treatments failed to deliver any impact (Hu et al, unpublished data) These findings suggest that RNAi technology can be further developed to control the spread of whiteflies
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
