MicroTom--a high-throughput model transformation system for functional genomics

• Published in: Plant cell reports 2006-05, Vol.25 (5), p.432-441
• Main Authors: Dan, Y, Yan, H, Munyikwa, T, Dong, J, Zhang, Y, Armstrong, C.L
• Format: Article
• Language: English
• Subjects: 3-Phosphoshikimate 1-Carboxyvinyltransferase - metabolism; 5-enolpyruvylshikimate-3-phosphate synthase; Agrobacterium tumefaciens; Agrobacterium tumefaciens - metabolism; alkyl (aryl) transferases; beta-glucuronidase; Biological and medical sciences; Biotechnology; cotyledons; functional genomics; Fundamental and applied biological sciences. Psychology; gene expression; Genes; Genetic engineering; Genetic Markers; Genetic technics; genetic transformation; genetic vectors; Genomics; Glucuronidase - metabolism; green fluorescent protein; Industrial production; kanamycin kinase; Kanamycin Kinase - metabolism; Lycopersicon esculentum; Lycopersicon esculentum - genetics; Lycopersicon esculentum - metabolism; Methods. Procedures. Technologies; micropropagation; Models, Genetic; Phenotypes; plant regeneration; Plant Structures - metabolism; Plant tissues; Plants, Genetically Modified; Prunus; Solanum lycopersicum var. lycopersicum; Tomatoes; Transformation, Genetic; transgenes; Transgenic animals and transgenic plants; Transgenic plants
• ISSN: 0721-7714; 1432-203X
• DOI: 10.1007/s00299-005-0084-3

We have developed a high-throughput Agrobacterium-mediated transformation model system using both nptII and the 5-enolpyruvylshikimate-3-phosphate synthase gene from Agrobacterium tumefaciens strain CP4 (cp4) based selections in MicroTom, a miniature rapid-cycling cherry tomato variety. With the NPTII selection system, transformation frequency calculated as independent transgenic events per inoculated explant ranged from 24 to 80% with an average of 56%, in industrial production scale transformation experiments. For CP4, with glyphosate selection, the average transformation frequency was 57%. Stable transformation frequency was positively correlated with transient expression (R=0.85), and variable with the genes of interest. DNA integration and germline transformation were confirmed by biological assay, Southern Blot analysis, and R1 phenotype segregation. Transgene expression was observed in leaf, root, stem, flower, and fruit tissues of the transgenic plants. Ninety-five percent of transgenic events coexpressed two introduced genes based on β-glucuronidase (GUS) and neonmycin phosphotransferase II (NPTII) expression. Seventy-five percent of transgenic events contained one to two copies of the introduced uidA (GUS) gene based on Southern analysis. Transgenic plants from the cotyledon explants to the transgenic plants transferred to soil were produced within about 2-3 months depending on the genes of interest. The utility of this MicroTom model transformation system for functional genomic studies, such as identification of genes related to important agricultural traits and gene function, is discussed.