Transgenic Tobacco Expressing the TAT-Helicokinin I-CpTI Fusion Protein Show Increased Resistance and Toxicity to Helicoverpa armigera (Lepidoptera: Noctuidae).

Zhou Zhou,Chunyan Yuan,Yongli Li,Yongan Zhang,Liangjian Qu

doi:10.3390/genes8010028

Abstract

Insect kinins were shown to have diuretic activity, inhibit weight gain, and have antifeedant activity in insects. In order to study the potential of the TAT-fusion approach to deliver diuretic peptides per os to pest insects, the HezK I peptide from Helicoverpa zea, as a representative of the kinin family, was selected. The fusion gene TAT-HezK I was designed and was used to transform tobacco plants. As a means to further improve the stability of TAT-HezK I, a fusion protein incorporating HezK I, transactivator of transcription (TAT), and the cowpea trypsin inhibitor (CpTI) was also designed. Finally, the toxicity of the different tobacco transgenic strains toward Helicoverpa armigera was compared. The results demonstrated that TAT-HezK I had high toxicity against insects via transgenic expression of the peptide in planta and intake through larval feeding. The toxicity of the fusion TAT-HezK I and CpTI was higher than the CpTI single gene in transgenic tobacco, and the fusion TAT-HezK I and CpTI further enhanced the stability and bioavailability of agents in oral administration. Our research helps in targeting new genes for improving herbivore tolerance in transgenic plant breeding.

Highlights

The insect kinins are multifunctional neuropeptides found in several arthropod and invertebrate groups [1]
Seinsche et al [5] demonstrated that the weight gain inhibition observed in H. virescens is accompanied by an increase in the excretion of water in the feces, consistent with the diuretic activity previously observed in crickets [7], flies [8,9], as well as the lepidopteran H. virescens [5]
The TAT-HezK I, cowpea trypsin inhibitor (CpTI), and TAT-HezK I-CpTI recombinant proteins were expressed via transgenic tobacco plants to assess the impact of oral delivery in H. armigera larvae

Summary

Introduction

The insect kinins are multifunctional neuropeptides found in several arthropod and invertebrate groups [1]. Insect kinins were shown to have diuretic activity on isolated Malpighian tubules of the cricket Acheta [2] and the yellow fever mosquito Aedes aegypti [3]. (Xaa1 2 = His, Asn, Phe, Ser, or Tyr; Xaa2 3 = Pro, Ser, or Ala). Insect kinins or their synthetic analogs have been reported to inhibit weight gain when fed to, or injected in larvae of tobacco budworm. Seinsche et al [5] demonstrated that the weight gain inhibition observed in H. virescens is accompanied by an increase in the excretion of water in the feces, consistent with the diuretic activity previously observed in crickets [7], flies [8,9], as well as the lepidopteran H. virescens [5].

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Conclusion