Fig. 3. Loss-of-function allele of TCL1. (A) Diagram illustrating the T-DNA insertion site in the tcl1-1 mutant. The T-DNA is inserted in the second intron of TCL1. (B) Expression of TCL1 in wild-type and tcl1-1 mutant Arabidopsis plants. Expression of ACTIN2 provided a control. (C) Comparison of trichome formation on the first pedicel and the internode subtending the site of the first flower on the main inflorescence of wild type (left), tcl1-1 mutant (middle) and tcl1-1 mutant transformed with P_TCL1:TCL1-GFP (right). Arrowheads indicate the site of the first flower/siliques on the main inflorescence stem. Arrows indicate trichomes formed on the main inflorescence stem and pedicel of the tcl1-1 mutant. Beneath is shown the results from RT-PCR in which GFP-specific primers were used to examine the expression of TCL1-GFP in P_TCL1:TCL1-GFP/tcl1-1 plants. Expression of ACTIN2 provided a control. (D) TCL1-GFP fluorescence in the epidermal cells of the lower part of the hypocotyl in a 4-day-old P_TCL1:TCL1-GFP seedling. Shown are differential interference contrast (left) and confocal (right) images of hypocotyl epidermal cells. Arrows point to the nucleus of a cell.