title: Rhizobium radiobacter conjugation and callus-independent shoot regeneration used to introduce the cercosporin export gene cfp from Cercospora into sugar beet (Beta vulgaris L.).
abstract: Leaf spot disease caused by Cercospora is responsible for crop and profitability losses in sugar beet crops in the US and worldwide. The cfp gene that encodes a protein that exports phytotoxic cercosporins from Cercospora was conjugally transferred to sugar beet using Rhizobium radiobacter (Agrobacterium tumefaciens), to improve Cercospora-induced leafspot resistance. Conditions for shoot regeneration were optimized to increase regeneration/transformation efficiencies. Low-light and room-temperature conditions were favorable to sugar beet regeneration without callus when cytokinin had been added to the tissue culture medium. Using this procedure adventitious shoots from leaf pieces were obtained in a simple, one-step regeneration procedure. T7, a cfp-transgenic clone verified by PCR with gene-specific primers, is being propagated for leaf spot disease resistance evaluation.
authors.affiliation: USDA, Agricultural Research Services, Beltsville Agricultural Research Center, Plant Science Institute, Molecular Plant Pathology Laboratory, 10300 Baltimore Av., Bldg 004 Rm 130, BARC-West, Beltsville, MD 20705, USA. kuykendl@ba.usda.gov
authors.forename: L David
authors.initials: LD
authors.lastname: Kuykendall
authors.forename: Tammy M
authors.initials: TM
authors.lastname: Stockett
authors.forename: Joseph W
authors.initials: JW
authors.lastname: Saunders
mesh_terms: D001203:Ascomycota / Q000235:genetics / Q000378:metabolism; D027461:Beta vulgaris / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D002352:Carrier Proteins; D002454:Cell Differentiation; D003227:Conjugation, Genetic; D046508:Culture Techniques / Q000379:methods; D005656:Fungal Proteins; D026901:Membrane Transport Proteins; D010569:Perylene / Q000031:analogs & derivatives* / Q000378:metabolism*; D010935:Plant Diseases / Q000382:microbiology; D018520:Plant Shoots / Q000235:genetics / Q000254:growth & development / Q000378:metabolism / Q000382:microbiology; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000096:biosynthesis; D012038:Regeneration / Q000502:physiology; D012231:Rhizobium / Q000235:genetics / Q000378:metabolism; D014170:Transformation, Genetic
chemical_list: D002352:Carrier Proteins; D005656:Fungal Proteins; D026901:Membrane Transport Proteins; D011994:Recombinant Proteins; C400126:cercosporin transporter protein, Cercospora; D010569:Perylene; C026363:cercosporin