High-efficiency transformation of the diploid strawberry (Fragaria vesca) for functional genomics

• Published in: Planta 2006-05, Vol.223 (6), p.1219-1230
• Main Authors: Oosumi, Teruko, Gruszewski, Hope A., Blischak, Leslie A., Baxter, Aaron J., Wadl, Phillip A., Shuman, Joel L., Veilleux, Richard E., Shulaev, Vladimir
• Format: Article
• Language: English
• Subjects: Agrobacterium; Agronomy. Soil science and plant productions; Bioinformatics; Biological and medical sciences; Callus; Cinnamates - pharmacology; Diploidy; Efficiency; Fragaria - anatomy & histology; Fragaria - genetics; Fragaria - growth & development; Fundamental and applied biological sciences. Psychology; Genetic engineering applications; Genetics; Genetics and breeding of economic plants; Genomics; Genomics - methods; Green Fluorescent Proteins - analysis; Hygromycin B - analogs & derivatives; Hygromycin B - pharmacology; Infections; Leaves; Memory interference; Mutagenesis, Insertional - methods; Plant breeding: fundamental aspects and methodology; Plant cells; Plant genetics; Plant growth; Plant Shoots - genetics; Plant Shoots - growth & development; Plants; Plants, Genetically Modified - anatomy & histology; Plants, Genetically Modified - genetics; Reproductive cycle; Rhizobium; Seed germination; Seeds; Transformation, Genetic; Transgenic plants
• ISSN: 0032-0935; 1432-2048
• DOI: 10.1007/s00425-005-0170-3

Fragaria vesca L., a diploid (2n = 2x = 14) relative of the commercial octoploid strawberry, is an attractive model for functional genomics research in Rosaceae. Its small genome size, short reproductive cycle, and facile vegetative and seed propagation make F. vesca a promising candidate for forward and reverse genetics experiments. However, the lack of a high-efficiency transformation protocol required for systematic production of thousands of T-DNA insertional mutant lines and high-throughput gene validation is a major bottleneck. We describe a new transformation procedure that uses leaf explants from newly unfolded trifoliate leaves obtained from stock plants 6—7 weeks after seed germination, co-cultivation with Agrobacterium strain GV3101, and stringent selection on MS medium containing 4 mg l-1 hygromycin. Using this protocol we achieved 100% transformation efficiency for 6 of 14 F. vesca accessions tested. Accession PI 551572 was determined to be the best candidate for a model in F. vesca functional genomics research, as it showed the greatest propensity for callus formation, transformation, shoot regeneration, ex vitro establishment, and plant growth, requiring only 14—15 weeks to complete its life cycle in different seasons in the greenhouse.