title: Cloning and molecular characterization of a novel lectin gene from Pinellia ternata.
abstract: The full-length cDNA of Pinellia ternata agglutinin (PTA) was cloned from inflorescences using RACE-PCR. Through comparative analysis of PTA gene (pta) and its deduced amino acid sequence with those of other Araceae species, pta was found to encode a precursor lectin with signal peptide and to have extensive homology with those of other Araceae species. PTA was a heterotetrameric mannose-binding lectin with three mannose-binding boxes like lectins from other Araceae and Amaryllidaceae species. Southern blot analysis of the genomic DNA revealed that pta belonged to a low-copy gene family. Northern blot analysis demonstrated that pta constitutively expressed in various plant tissues including root, leaf, stem and inflorescence. The pta cDNA sequence encoding for mature PTA protein was cloned into pET-32a plasmid and the resulting plasmid, pET-32a-PTA containing Trx-PTA fusion protein, was investigated for the expression in E. coli BL21. SDS-PAGE gel analysis showed that the Trx-PTA fusion protein was successfully expressed in E. coli BL21 when induced by IPTG. Artificial diet assay revealed that PTA fusion protein had significant levels of resistance against peach potato aphids when incorporated into artificial diet at 0.1% (w/v). The cloning of the pta gene will enable us to further test its effect in depth on aphids by transferring the gene into crop plants.
authors.affiliation: State Key Laboratory of Genetic Engineering, School of Life Sciences, Morgan-Tan International Center for Life Sciences, Fudan-SJTU-Nottingham Plant Biotechnology R and D Center, Fudan University, Shanghai 200433, China.
authors.forename: Jian Hong
authors.initials: JH
authors.lastname: Yao
authors.forename: Xiu Yun
authors.initials: XY
authors.lastname: Zhao
authors.forename: Zhi Hua
authors.initials: ZH
authors.lastname: Liao
authors.forename: Juan
authors.initials: J
authors.lastname: Lin
authors.forename: Zhong Hai
authors.initials: ZH
authors.lastname: Chen
authors.forename: Fei
authors.initials: F
authors.lastname: Chen
authors.forename: Jun
authors.initials: J
authors.lastname: Song
authors.forename: Xiao Fen
authors.initials: XF
authors.lastname: Sun
authors.forename: Ke Xuan
authors.initials: KX
authors.lastname: Tang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001042:Aphids / Q000378:metabolism; D001483:Base Sequence; D003001:Cloning, Molecular; D008958:Models, Molecular; D008969:Molecular Sequence Data; D030021:Pinellia / Q000235:genetics; D037121:Plant Lectins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D016415:Sequence Alignment
chemical_list: C047938:Pinellia ternata lectin; D037121:Plant Lectins; D011993:Recombinant Fusion Proteins