title: The characterization of SaPIN2b, a plant trichome-localized proteinase inhibitor from Solanum americanum.
abstract: Proteinase inhibitors play an important role in plant resistance of insects and pathogens. In this study, we characterized the serine proteinase inhibitor SaPIN2b, which is constitutively expressed in Solanum americanum trichomes and contains two conserved motifs of the proteinase inhibitor II (PIN2) family. The recombinant SaPIN2b (rSaPIN2b), which was expressed in Escherichia coli, was demonstrated to be a potent proteinase inhibitor against a panel of serine proteinases, including subtilisin A, chymotrypsin and trypsin. Moreover, rSaPIN2b also effectively inhibited the proteinase activities of midgut trypsin-like proteinases that were extracted from the devastating pest Helicoverpa armigera. Furthermore, the overexpression of SaPIN2b in transgenic tobacco plants resulted in enhanced resistance against H. armigera. Taken together, our results demonstrated that SaPIN2b is a potent serine proteinase inhibitor that may act as a protective protein in plant defense against insect attacks.
authors.affiliation: State Key Laboratory of Biocontrol and Key Laboratory of Gene Engineering of the Ministry of Education, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China. zfxu@xtbg.ac.cn.
authors.forename: Ming
authors.initials: M
authors.lastname: Luo
authors.forename: Ling-Wen
authors.initials: LW
authors.lastname: Ding
authors.forename: Zhi-Juan
authors.initials: ZJ
authors.lastname: Ge
authors.forename: Zhen-Yu
authors.initials: ZY
authors.lastname: Wang
authors.forename: Bo-Lun
authors.initials: BL
authors.lastname: Hu
authors.forename: Xiao-Bei
authors.initials: XB
authors.lastname: Yang
authors.forename: Qiao-Yang
authors.initials: QY
authors.lastname: Sun
authors.forename: Zeng-Fu
authors.initials: ZF
authors.lastname: Xu
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D004305:Dose-Response Relationship, Drug; D015870:Gene Expression; D008969:Molecular Sequence Data; D009036:Moths / Q000201:enzymology; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000494:pharmacology*; D030821:Plants, Genetically Modified; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000494:pharmacology; D016415:Sequence Alignment; D015842:Serine Proteinase Inhibitors / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D032322:Solanum / Q000737:chemistry*; D014026:Nicotiana / Q000235:genetics / Q000469:parasitology; D064201:Trichomes / Q000737:chemistry*
chemical_list: C445075:PIN2 protein, Solanum americanum; D010940:Plant Proteins; D011994:Recombinant Proteins; D015842:Serine Proteinase Inhibitors