Scheme of the GUS gene expression cassette in constructs used in transfection experiments: 4.8-kb-long T-DNA (A) and pACT-1D/PstI (B). RB and iRB indicate the right border and inverted right border of the Agrobacterium pTi plasmid; P1 and P2 represent 200-bp-long fragments of the pBluescript vector backbone flanking the GUS expression cassette in pACT-1D. PAct-intron, Fusion of rice actin promoter and intron (1.4 kb) preceded by a 0.9-kb-long rice genomic sequence (RS). GUS indicates 1.8-kb-long gene coding for bacterial β-glucuronidase, whereas Tnos indicates the 0.3-kb-long terminator of the nopaline synthase gene (nos). Arrows, Position and direction of primers used for the detection of the transgene and for analysis of its intactness. The BamHI and XbaI recognition sites, as well as the annealing site for the GUS probe used in Southern-blot analysis, are also indicated.