title: Effective delivery of a nematode-repellent peptide using a root-cap-specific promoter.
abstract: The potential of the MDK4-20 promoter of Arabidopsis thaliana to direct effective transgenic expression of a secreted nematode-repellent peptide was investigated. Its expression pattern was studied in both transgenic Arabidopsis and Solanum tuberosum (potato) plants. It directed root-specific β-glucuronidase expression in both species that was chiefly localized to cells of the root cap. Use of the fluorescent timer protein dsRED-E5 established that the MDK4-20 promoter remains active for longer than the commonly used constitutive promoter CaMV35S in separated potato root border cells. Transgenic Arabidopsis lines that expressed the nematode-repellent peptide under the control of either AtMDK4-20 or CaMV35S reduced the establishment of the beet cyst nematode Heterodera schachtii. The best line using the AtMDK4-20 promoter displayed a level of resistance >80%, comparable to that of lines using the CaMV35S promoter. In transgenic potato plants, 94.9 ± 0.8% resistance to the potato cyst nematode Globodera pallida was achieved using the AtMDK4-20 promoter, compared with 34.4 ± 8.4% resistance displayed by a line expressing the repellent peptide from the CaMV35S promoter. These results establish the potential of the AtMDK4-20 promoter to limit expression of a repellent peptide whilst maintaining or even improving the efficacy of the cyst-nematode defence.
authors.affiliation: Centre for Plant Sciences, University of Leeds, Leeds, UK. c.j.lilley@leeds.ac.uk
authors.forename: Catherine J
authors.initials: CJ
authors.lastname: Lilley
authors.forename: Dong
authors.initials: D
authors.lastname: Wang
authors.forename: Howard J
authors.initials: HJ
authors.lastname: Atkinson
authors.forename: Peter E
authors.initials: PE
authors.lastname: Urwin
mesh_terms: D000818:Animals; D017360:Arabidopsis / Q000235:genetics*; D005818:Genetic Engineering; D049452:Green Fluorescent Proteins / Q000032:analysis; D009348:Nematoda / Q000187:drug effects*; D010455:Peptides / Q000235:genetics* / Q000378:metabolism; D010571:Pest Control / Q000379:methods*; D018517:Plant Roots / Q000235:genetics / Q000378:metabolism / Q000469:parasitology; D030821:Plants, Genetically Modified / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011198:Solanum tuberosum / Q000235:genetics* / Q000469:parasitology
chemical_list: D010455:Peptides; D049452:Green Fluorescent Proteins