Molecular characterization and expression of laccase genes in the salivary glands of the green rice leafhopper, Nephotettix cincticeps (Hemiptera: Cicadellidae)

作者：Hattori Makoto^*; Tsuchihara Kazuko; Noda Hiroaki; Konishi Hirosato; Tamura Yasumori; Shinoda Tetsuro; Nakamura Masatoshi; Hasegawa Tsuyoshi

来源：Insect Biochemistry and Molecular Biology, 2010, 40(4): 331-338.

DOI：10.1016/j.ibmb.2010.02.009

• Green rice leafhopper
• Nephotettix cincticeps
• Salivary laccase
• Molecular characterization
• In situ hybridization

The green rice leafhopper, Nephotettix cincticeps has a laccase (EC 1.10.3.2) in its salivary glands and saliva, possibly playing an important role in detoxifying plant phenolics and in salivary sheath coagulation during feeding. We aimed to clarify the function of saliva-specific laccase in a vascular-feeding insect, N. cincticeps, for which we cloned 2 cDNAs (NcLac1S and NcLac1G) from the salivary glands and 1 cDNA (NcLac2) from the epidermis. The NcLac1S, NcLac1G, and NcLac2 transcripts encoded 701-, 792-, and 729-amino-acid proteins, respectively. The putative proteins encoded by NcLac1S and NcLac2 were predicted to be soluble, whereas that encoded by NcLacl G was hydrophobic and predicted to have a C-terminal transmembrane domain. Real-time reverse transcriptase polymerase chain reaction analysis revealed that NcLac1S was expressed exclusively, and at a much higher level than NcLacl G and NcLac2 in the salivary glands. NcLac1G was also expressed in the epidermis, midgut, and Malpighian tubules. NcLac2 expression was highest in the epidermis. In situ hybridization revealed NcLac1S expression in the V-cells of the salivary glands, having proven laccase activity. Expression of NcLacl G and NcLac2 were not detected clearly in all cells in the salivary glands. Therefore, NcLac1S is responsible for the laccase activity detected in the salivary glands and saliva of this insect. This is the first report on gene cloning of salivary laccase from a vascular-feeding insect.

• 出版日期2010-4