Genetic structure of the expression vectors and the recombinant locus.

<p>Note that only the T-DNA part of the vectors is illustrated (not drawn to scale). The integrase is expressed from the pICH13130 or pICH14313 constructs. The pHW511 vector harbors the <i>attP</i> and <i>attB</i> sequences, which serve as targets for recombination that results in the derivative locus HW511^R and the released excision circle. To select transgenic plants carrying the locus ICH13130 or ICH14313, co-transformation with the vector carrying an HPT selection marker was performed (p6U, not shown). Abbreviations: <i>phiC31</i>, phage phiC31 recombinase coding sequence <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0045353#pone.0045353-Thorpe2" target="_blank">[41]</a>; <i>Pubi</i>, maize <i>ubiquitin 1</i> promoter; <i>Pspm</i>, promoter of the maize suppressor-mutator transposable element <i>spm</i>; <i>intron</i>, sequence derived from an intron of the <i>Petunia hybrida Psk7</i> gene (GenBank accession number AJ224165); <i>NLS</i>, SV40 T antigen nuclear localization signal, amino acids PKKKRKV <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0045353#pone.0045353-Andreas1" target="_blank">[31]</a>; <i>Tnos</i>, <i>nopaline synthase</i> terminator; <i>T35S</i>, cauliflower mosaic virus (CaMV) <i>35S</i> terminator; <i>GFP</i>, coding sequence for the green fluorescent protein; <i>GUS</i>, <i>β-glucuronidase</i> (<i>gusA</i>) gene; <i>Pact</i>, rice <i>actin 1</i> promoter; <i>attP</i> and <i>attB</i>, <i>Streptomyces</i> phage phiC31 recombination sites; <i>attR</i> and <i>attL</i>, hybrid products that originate from the recombination between <i>attP</i> and <i>attB; HPT</i>, <i>hygromycin phosphotransferase</i> gene.