title: Combined expression of antimicrobial genes (Bbchit1 and LJAMP2) in transgenic poplar enhances resistance to fungal pathogens.
abstract: Populus species are susceptible to infection by microbial pathogens that severely affect their growth and substantially decrease their economic value. In this study, two pathogenesis-related protein genes consisting of Beauveria bassiana chitinase (Bbchit1) and motherwort lipid-transfer protein (LJAMP2) were introduced into Chinese white poplar (Populus tomentosa Carr.) via Agrobacterium-mediated transformation using the hygromycin (hyg) and neomycin phosphotransferase (NPTII) genes as selectable markers, respectively. Polymerase chain reaction analysis confirmed the stable integration of transgenes in the genome of transgenic plants. In vitro assays showed that inhibitory activity against the fungal pathogen Alternaria alternata (Fr.) Keissler was evident from the crude leaf extracts from transgenic plants. Importantly, the double-transgenic plants exhibited significantly higher resistance to the pathogen than either of the single-gene transformants and wild-type plants when inoculated with A. alternata. The level of disease reduction in double-transgenic lines was between 82 and 95%, whereas that of single-gene transformants carrying either LJAMP2 or Bbchit1 was between 65 and 89%. These results indicated that the combined expression of the LJAMP2 and Bbchit-1 genes could significantly enhance resistance to necrotrophic fungal pathogens in poplar.
authors.affiliation: Key Laboratory of Eco-environments of Three Gorges Reservoir Region, Ministry of Education, Institute of Resources Botany, School of Life Sciences, Southwest University, Chongqing 400715, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Huang
authors.forename: Hong
authors.initials: H
authors.lastname: Liu
authors.forename: Zhichun
authors.initials: Z
authors.lastname: Jia
authors.forename: Qing
authors.initials: Q
authors.lastname: Fang
authors.forename: Keming
authors.initials: K
authors.lastname: Luo
mesh_terms: D000528:Alternaria / Q000187:drug effects / Q000254:growth & development / Q000472:pathogenicity; D000890:Anti-Infective Agents / Q000494:pharmacology*; D052982:Beauveria / Q000235:genetics*; D001681:Biological Assay; D002688:Chitinases / Q000235:genetics / Q000494:pharmacology*; D018076:DNA, Complementary / Q000235:genetics; D060467:Disease Resistance; D005656:Fungal Proteins / Q000235:genetics / Q000494:pharmacology; D025301:Hyphae / Q000187:drug effects / Q000254:growth & development; D031332:Leonurus / Q000235:genetics*; D010935:Plant Diseases / Q000276:immunology* / Q000382:microbiology; D018515:Plant Leaves / Q000235:genetics / Q000276:immunology / Q000382:microbiology; D010940:Plant Proteins / Q000494:pharmacology; D030821:Plants, Genetically Modified; D032107:Populus / Q000235:genetics / Q000276:immunology* / Q000382:microbiology; D018749:RNA, Plant / Q000235:genetics; D019076:Transgenes
chemical_list: D000890:Anti-Infective Agents; D018076:DNA, Complementary; D005656:Fungal Proteins; D010940:Plant Proteins; D018749:RNA, Plant; C053376:pathogenesis-related proteins, plant; D002688:Chitinases