title: Gastrodia anti-fungal protein from the orchid Gastrodia elata confers disease resistance to root pathogens in transgenic tobacco.
abstract: Diseases of agricultural crops are caused by pathogens from several higher-order phylogenetic lineages including fungi, straminipila, eubacteria, and metazoa. These pathogens are commonly managed with pesticides due to the lack of broad-spectrum host resistance. Gastrodia anti-fungal protein (GAFP; gastrodianin) may provide a level of broad-spectrum resistance due to its documented anti-fungal activity in vitro and structural similarity to insecticidal lectins. We transformed tobacco (Nicotiana tabacum cv. Wisconsin 38) with GAFP-1 and challenged transformants with agriculturally important plant pathogens from several higher-order lineages including Rhizoctonia solani (fungus), Phytophthora nicotianae (straminipile), Ralstonia solanacearum (eubacterium), and Meloidogyne incognita (metazoan). Quantitative real-time PCR and western blotting analysis indicated that GAFP-1 was transcribed and translated in transgenic lines. When challenged by R. solani and P. nicotianae, GAFP-1 expressing lines had reduced symptom development and improved plant vigor compared to non-transformed and empty vector control lines. These lines also exhibited reduced root galling when challenged by M. incognita. Against R. solanacearum expression of GAFP-1 neither conferred resistance, nor exacerbated disease development. These results indicate that heterologous expression of GAFP-1 can confer enhanced resistance to a diverse set of plant pathogens and may be a good candidate gene for the development of transgenic, root-disease-resistant crops.
authors.affiliation: Department of Entomology, Soils, and Plant Sciences, 114 Long Hall, Clemson University, Clemson, SC 29634, USA.
authors.forename: K D
authors.initials: KD
authors.lastname: Cox
authors.forename: D R
authors.initials: DR
authors.lastname: Layne
authors.forename: R
authors.initials: R
authors.lastname: Scorza
authors.forename: G
authors.initials: G
authors.lastname: Schnabel
mesh_terms: D001483:Base Sequence; D017931:DNA Primers; D031668:Gastrodia / Q000737:chemistry*; D037241:Mannose-Binding Lectins / Q000302:isolation & purification / Q000494:pharmacology*; D010940:Plant Proteins / Q000302:isolation & purification / Q000494:pharmacology*; D030821:Plants, Genetically Modified / Q000382:microbiology*; D014026:Nicotiana / Q000382:microbiology*
chemical_list: D017931:DNA Primers; D037241:Mannose-Binding Lectins; D010940:Plant Proteins; C437088:gastrodianin