›› 2018, Vol. 61 ›› Issue (6): 657-667.doi: 10.16380/j.kcxb.2018.06.004

• RESEARCH PAPERS • Previous Articles     Next Articles

Molecular cloning, tissue expression profiling and binding characterization of the pheromone binding protein SlitPBP4 from Spodoptera litura (Lepidoptera: Noctuidae)

SUN Jia-Bin1, LIU Nai-Yong2, LI Shuang-Mei1, YAN Qi1, DONG Shuang-Lin1,*    

  1.  (1. Key Laboratory of Monitoring and Management of Crop Diseases and Pest Insects, Ministry of Agriculture, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China; 2. Key Laboratory of Forest Disaster Warning and Control of Yunnan Province, Southwest Forestry University, Kunming 650224, China)
  • Online:2018-06-20 Published:2018-06-20

Abstract:  【Aim】 This study aims to identify the new pheromone binding protein (PBP) gene of Spodoptera litura, to clarify its tissue expression pattern and to explore its functions. 【Methods】 Based on the sequence characteristics of PBP4 homologues and their vicinity with other PBP genes on the chromosome in four non-noctuid species (Manduca sexta, Bombyx mori, Danausplexippus and Melitaea cinxia) reported previously, a PBP4 gene was obtained from S. litura by analyzing S. litura PBP/GOBP genes previously cloned by our laboratory. The tissue expression patterns of this gene in male and female adults were determined by RT-PCR and qPCR. The binding properties of the recombinant PBP4 protein to sex pheromone components and plant odorants were measured by fluorescence competitive binding assay. 【Results】 The first PBP4 gene in Noctuidae was identified from S. litura and named SlitPBP4, which was deposited in GenBank under accession number MG356847. The cDNA sequence of SlitPBP4 encodes 210 amino acids, with the typical sequence features of PBPs, including an N terminal signal peptide, several hydrophobic regions, six conserved cysteines, and two introns inserted at the conserved positions in the genomic DNA. However, SlitPBP4 has a C terminus much longer than that of the other three reported SlitPBPs. SlitPBP4 showed predominantly high expression level in the male abdomen (the reproductive systems) but nearly undetectable in the antennae and other adult tissues. Fluorescence competitive binding assay showed that SlitPBP4 protein had no obvious binding ability to the tested pheromone components and plant odors. 【Conclusion】 The first PBP4 gene of noctuids was reported. SlitPBP4 is likely to be involved primarily in the reproduction-related physiological processes in male adults, rather than the olfactory function of other reported PBP genes in noctuids.

Key words: Spodoptera litura, SlitPBP4, tissue expression, prokaryotic expression, fluorescence competitive binding assay