T-DNA tagging of a flowering-time gene and improved gene transfer by in planta transformation of Arabidopsis

Abstract

Gene tagging with insertional mutagens greatly facilitates the isolation of novel genes. A new collection of Arabidopsis T-DNA tag insertion lines (n=2165) was generated by in planta transformation. Whole plants were vacuum-infiltrated in a suspension of Agrobacterium carrying the pGKB5 tagging vector. The efficiency of transformation increased with addition of the surfactant Silwet L-77 (0.005% v/v) to the Agrobacterium suspension. Visual screens of the T-DNA lines identified two mutants with floral defects. Allelism tests suggested that a mutation in the GIGANTEA gene was responsible for the late-flowering phenotype of one of the mutants. Linkage analysis indicated that the GIGANTEA gene was tagged in this mutant.