Fig. 1. Detailed genomic structure characterization of the T-DNA inserts in transgenic Arabidopsis thaliana line EL702C. (a) Schematic construct map of the T-DNA region in the binary vector pEL702. The plasmid was designed such that the DNA between the right and left borders (T-DNA) can be transferred into plant nuclei via Agrobacterium. Thus, when stable transgenic Arabidopsis plants are treated with the synthetic glucocorticoid dexamethasone (Dex), the expressed fusion proteins can localize to the integrated loci by association with the lac operator array. The numbers on the top indicate the size of DNA construct in kbp. The arrow indicates the orientation of T-DNA from the left border to right border. Colored areas indicate gene expression cassette: blue, glucocorticoid receptor expression; yellow, hygromycin phosphotransferase expression; green, GFP-LacI/NLS induced expression. Abbreviations and symbols: blue dot rectangle, pea rbcS-E9 terminator; blue triangle, cauliflower mosaic virus 35S promoter; green dot rectangle, pea rbcS-3A terminator; green rectangle, 6XGal4 UAS and TATA box; yellow dot rectangle, nopaline-synthase gene terminator; yellow triangle, nopaline-synthase gene promoter; GVG, glucocorticoid binding domain/VP16 acidic activation domain/Gal4 DNA-binding domain; HPT, hygromycin phosphotransferase; LacO, 256mer of lac operator arrays; LB, left border; RB, right border. (b) Molecular characterization of the integrated loci with T-DNAs. The number of integrated loci was first characterized by Southern blot analyses, and the borders of the insertion sites were subsequently defined by subcloning and sequencing of the respective regions for the different sites using various strategies. The solid circle indicates the location of the centromere. The entire length of the chromosome and the distance between the two insertion loci are indicated in Mbp. Arrows indicate the direction of T-DNAs from LB to RB. Shaded rectangles represent neighboring reading frames around the T-DNA inserts.