Lookup NU author(s): Dr Martin Edwards,
Professor Angharad MR Gatehouse
This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).
Recombinant fusion proteins containing arthropod toxins have been developed as a new class of biopesticides. The recombinant fusion protein HO a/GNA, containing the spider venom toxin omega-ACTX-1-Hv1a linked to snowdrop lectin (GNA) was shown to reduce survival of the peach-potato aphid Myzus persicae when delivered in artificial diet, with survival <10% after 8 days exposure to fusion protein at 1 mg/ml. Although the fusion protein was rapidly degraded by proteases in the insect, HO a/GNA oral toxicity to M. persicae was significantly greater than GNA alone. A construct encoding the fusion protein, including the GNA leader sequence, under control of the constitutive CaMV 35S promoter was transformed into Arabidopsis; the resulting plants contained intact fusion protein in leaf tissues at an estimated level of 25.6 +/- 4.1 ng/mg FW. Transgenic Arabidopsis expressing Hv1a/GNA induced up to 40% mortality of M. persicae after 7 days exposure in detached leaf bioassays, demonstrating that transgenic plants can deliver fusion proteins to aphids. Grain aphids (Sitobion avenae) were more susceptible than M. persicae to the HO a/GNA fusion protein in artificial diet bioassays (LC50 = 0.73 mg/ml after 2 days against LC50 = 1.81 mg/ml for M. persicae), as they were not able to hydrolyze the fusion protein as readily as M. persicae. Expression of this fusion protein in suitable host plants for the grain aphid is likely to confer higher levels of resistance than that shown with the M. persicae/Arabidopsis model system.
Author(s): Nakasu EYT, Edwards MG, Fitches E, Gatehouse JA, Gatehouse AMR
Publication type: Article
Publication status: Published
Journal: Frontiers in Plant Science
Online publication date: 28/11/2014
Acceptance date: 12/11/2014
Date deposited: 17/09/2015
ISSN (electronic): 1664-462X
Publisher: Frontiers Research Foundation
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