Agrobacterium-mediated transformation of seedling-derived maize callus.
Efficient production of seedling-derived Type I callus was demonstrated for several corn genotypes including commercial inbred lines. Seeds were germinated on MS-based medium containing 10 mg l(-1) picloram and 3 mg l(-1) 6-benzylaminopurine, which induced the development of axillary buds in the area of coleoptilar node. Nodal sections of 7-10-day old seedlings were isolated, split longitudinally, and placed on callus induction medium supplemented with 2.2 mg l(-1) picloram and 0.5 mg l(-1) 2,4-dichlorophenoxyacetic acid. For lines L4 and L9 the frequency of embryogenic callus induction was 38-42% based on calli per split nodal section. Frequency of callus induction from split nodal sections of seeds germinated on media without growth regulators was 0-3%. Seedling-derived callus of five genotypes was used for Agrobacterium-mediated transformation. Two constructs containing the green fluorescence protein gene and genes for either neomycin phosphotransferase II or glyphosate selection were used in transformation experiments. Transformation frequency varied from 2 to 11% and about 60% of the T(0) plants had 1-2 copies of transgenes.
Sidorov
Vladimir
V
Monsanto Company, 700 Chesterfield Parkway North, St. Louis, MO 63017, USA. vladimir.a.sidorov@monsanto.com
Gilbertson
Larry
L
Addae
Prince
P
Duncan
David
D
D018506:Gene Expression Regulation, Plant; D005838:Genotype; D049452:Green Fluorescent Proteins / Q000378:metabolism; D030821:Plants, Genetically Modified; D012038:Regeneration; D012231:Rhizobium / Q000235:genetics* / Q000502:physiology; D036226:Seedlings / Q000235:genetics / Q000254:growth & development*; D046509:Tissue Culture Techniques; D014170:Transformation, Genetic; D003313:Zea mays / Q000235:genetics* / Q000254:growth & development*
D049452:Green Fluorescent Proteins