Submitted to: Congress on In Vitro Biology
Publication Type: Abstract Only
Publication Acceptance Date: 6/28/1996
Publication Date: N/A
Citation: Interpretive Summary:
Technical Abstract: Transformation of some non-cereal monocots has been more efficient with expression cassettes that contain a strong dicot promoter rather than a cereal promoter. This study evaluates the transformation of two Allium species, garlic and onion, for promoter activity and osmoticum effect using particle bombardment as the method of gene delivery. Callus was produced from root segments on a modified B-5 medium of four garlic clones, and on BDS medium for one onion inbred. Suspension cultures using six month old callus were established on a modified B-5 medium + 2,4-D for garlic, and on BDS medium for onion. Cells were collected by vacuum filtration for transformation experiments. The activity of CaMV 35S, maize Adh1, and rice Act promoters was evaluated for transient expression using the Beta-glucuronidase (GUS) reporter gene. Osmotic conditioning of cells was performed by adding both mannitol and sorbitol to the medium. Osmoticum effect was evaluated for enhancement of transformation efficiency using GUS. CaMV 35S promoter activity was much higher for garlic and onion than either the maize Adh1 or rice Act promoters. Osmoticum did not enhance promoter activity in garlic but differences among garlic clones were observed. Osmotic conditioning in onion greatly improved the efficiency of the CaMV 35S promoter at the 0.5M osmoticum level.