“…First, they have been successfully employed for the removal of selectable markers from transgenic plants (Hoa et al, 2002;Zhang et al, 2003;Srivastava and Ow, 2004;Sreekala et al, 2005;Wang et al, 2005;Jia et al, 2006;Moore and Srivastava, 2006), and, second, they can be used to precisely integrate single-copy transgenes into the plant genome (Albert et al, 1995;Day et al, 2000;Srivastava and Ow, 2002;Lyznik et al, 2003;Chawla et al, 2006). This latter approach requires two rounds of transformation: in the first, a target site, such as the loxP site, is randomly introduced into the plant genome, and, in the second, a loxP-containing DNA construct is integrated into this genomic target site.…”