Fused: a promising molecular target for an RNAi-based strategy to manage Bt resistance in Plutella xylostella (L.)

• Published in: Journal of pest science 2022, Vol.95 (1), p.101-114
• Main Authors: Kang, Shi, Sun, Dan, Qin, Jianying, Guo, Le, Zhu, Liuhong, Bai, Yang, Wu, Qingjun, Wang, Shaoli, Zhou, Xuguo, Guo, Zhaojiang, Zhang, Youjun
• Format: Article
• Language: English
• Subjects: Agriculture; Biomedical and Life Sciences; Biotechnology; Butterflies & moths; Commercialization; Crops; Cry1Ac toxin; Deregulation; Ecology; Entomology; Forestry; Gene expression; Hedgehog protein; Insecticide resistance; Insects; Kinases; Life Sciences; Mode of action; Nontarget organisms; Original Paper; Pest resistance; Pesticides; Pests; Plant Pathology; Plant protection; Plant Sciences; Plutella xylostella; Product safety; Protein-serine/threonine kinase; RNA-mediated interference; Signal transduction; Soil bacteria; Soil microorganisms; Strains (organisms); Transgenic plants
• ISSN: 1612-4758; 1612-4766
• DOI: 10.1007/s10340-021-01374-3

Bacillus thuringiensis (Bt), a naturally occurring entomopathogenic soil bacterium, has been the active ingredient of sprayable Bt biopesticides for over a century. Insecticidal Bt Cry proteins are particularly well suited for use as plant-incorporated protectants in transgenic crops (Bt crops) due to their specificity against insect pests and safety for non-target organisms. The sustainability of these Bt products, however, has been challenged by the development of resistance in the field. RNA interference (RNAi), a species-specific control alternative that has been deregulated and commercialized in the USA and Canada, provides a new mode of action to complement the existing Bt products. Based on our preliminary research, we hypothesized that pyramiding/integrating Bt with RNAi can address/manage resistance issues related to Bt traits. To examine this overarching hypothesis, we (1) cloned and characterized a serine/threonine kinase gene ( fused ) of the Hedgehog (Hh) signaling pathway in the diamondback moth, Plutella xylostella (L.), a global superpest; (2) profiled Pxfused expression in Bt-resistant P. xylostella strains; and (3) investigated the involvement of Pxfused in Bt Cry1Ac resistance in P. xylostella . Pxfused expression was elevated ubiquitously in all Bt-resistant strains, and silencing of Pxfused led to larval and pupal mortality in both Cry1Ac-susceptible and -resistant strains, suggesting that Pxfused is a potential target for RNAi-based resistance management. Taken together, our results not only identify a molecular target to control a devastating lepidopteran pest, but also shed light on a novel resistance management strategy through the integration of two biotechnological techniques with distinct modes of action.