title: Adaptation of Spodoptera exigua (Lepidoptera: Noctuidae) to barley trypsin inhibitor BTI-CMe expressed in transgenic tobacco.
abstract: Nicotiana tabacum plants were transformed with the cDNA of barley trypsin inhibitor BTI-CMe under the control of the 35S CaMV promoter. Although the transgene was expressed and the protein was active in the homozygous lines selected, growth of Spodoptera exigua (Lepidoptera: Noctuidae) larvae reared on transgenic plants was not affected. The protease activity in larval midgut extracts after 2 days feeding on transformed tobacco leaves from the highest expressing plant showed a reduction of 25% in the trypsin-like activity compared to that from insects fed on non-transformed controls. The susceptibility of digestive serine-proteases to inhibition by BTI-CMe was confirmed by activity staining gels. This decrease was compensated with a significant induction of leucine aminopeptidase-like and carboxipeptidase A-like activities, while chymotrypsin-, elastase-, and carboxipeptidase B-like proteases were not affected.
authors.affiliation: Laboratorio de Bioqúimica y Biología Molecular, Dpto. de Biotecnología-UPM, E.T.S. Ingenieros Agrónomos, Madrid, Spain.
authors.forename: P
authors.initials: P
authors.lastname: Lara
authors.forename: F
authors.initials: F
authors.lastname: Ortego
authors.forename: E
authors.initials: E
authors.lastname: Gonzalez-Hidalgo
authors.forename: P
authors.initials: P
authors.lastname: Castañera
authors.forename: P
authors.initials: P
authors.lastname: Carbonero
authors.forename: I
authors.initials: I
authors.lastname: Diaz
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology*; D000818:Animals; D001681:Biological Assay; D015153:Blotting, Western; D004064:Digestive System / Q000201:enzymology; D004591:Electrophoresis, Polyacrylamide Gel; D015870:Gene Expression; D001467:Hordeum / Q000235:genetics*; D007814:Larva; D010940:Plant Proteins / Q000096:biosynthesis* / Q000235:genetics; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism*; D010947:Plants, Toxic; D012333:RNA, Messenger / Q000032:analysis / Q000302:isolation & purification; D012697:Serine Endopeptidases / Q000378:metabolism; D018411:Spodoptera / Q000502:physiology*; D014026:Nicotiana / Q000235:genetics / Q000378:metabolism*; D014361:Trypsin Inhibitors / Q000096:biosynthesis* / Q000235:genetics
chemical_list: C062960:ITR protein, Hordeum vulgare; D010940:Plant Proteins; D012333:RNA, Messenger; D014361:Trypsin Inhibitors; D012697:Serine Endopeptidases