Acta Entomologica Sinica ›› 2020, Vol. 63 ›› Issue (7): 807-816.doi: 10.16380/j.kcxb.2020.07.004

• RESEARCH PAPERS • Previous Articles     Next Articles

Tissue expression profiling and ligand binding characterization of the Plus-C odorant binding protein PsauOBP7 of Peridroma saucia(Lepidoptera: Noctuidae)

SUN Ya-Lan, LV Qi-Hui, YANG Hai-Bo, HU Zhen-Jie, LI Ding-Xu, DONG Jun-Feng*    

  1. (Forestry College, Henan University of Science and Technology, Luoyang, Henan 471023, China)
  • Online:2020-07-20 Published:2020-07-29

Abstract: 【Aim】 To clarify the expression profile of the Plus-C odorant binding protein PsauOBP7 in different chemosensory organs of the variegated cutworm, Peridroma saucia, and to analyze the odorant binding characteristics of the recombinant PsauOBP7. 【Methods】 The expression profile of PsauOBP7 in antennae, mouthparts, legs and wings of female and male moths of P. saucia was detected by qRT-PCR. The recombinant PsauOBP7 was expressed in prokaryotic expression system and purified. The expression profiles of PsauOBP7 in the head of different instar larvae and different adult tissues of P. saucia were analyzed by Western blot. The binding capabilities of the recombinant PsauOBP7 to 39 odor compounds were detected by fluorescence competitive binding assay. 【Results】 The recombinant PsauOBP7 was successfully expressed and purified. The qRT-PCR and Western blot assays showed that PsauOBP7 was expressed in the head of the 4th-6th instar larvae and the antennae, mouthparts, legs, and wings of female and male adults of P. saucia. The fluorescence competitive binding experiment showed that the binding ability of PsauOBP7 to (E)-2-hexenal was the strongest, with the Ki value of 1.4 μmol/L. In addition, PsauOBP7 had certain binding abilities to five ester compounds, dodecyl acetate, (Z)-3-hexenyl acetate, phenylethyl acetate, hexyl benzoate, and methyl cinnamate, with the Ki values of 5.7, 6.5, 8.9, 9.5, and 10.2 μmol/L, respectively. PsauOBP7 also had strong binding ability to two alcohols, (Z)-3-hexen-1-ol and farnesol, with the Ki values of 5.8 and 5.9 μmol/L, respectively. 【Conclusion】 The Plus-C odorant binding protein PsauOBP7 of P. saucia is expressed in various chemosensory organs of its larvae and adults, and can bind with a variety of plant odor compounds, suggesting that it plays an important role in searching for host plants of P. saucia.

Key words: Peridroma saucia, odorant binding protein, prokaryotic expression, Western blot, ligand, fluorescence competitive binding experiment