Ruf Stephanie, Karcher Daniel, Bock Ralph
Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany.
Proc Natl Acad Sci U S A. 2007 Apr 24;104(17):6998-7002. doi: 10.1073/pnas.0700008104. Epub 2007 Apr 9.
Plastids (chloroplasts) are maternally inherited in most crops. Maternal inheritance excludes plastid genes and transgenes from pollen transmission. Therefore, plastid transformation is considered a superb tool for ensuring transgene containment and improving the biosafety of transgenic plants. Here, we have assessed the strictness of maternal inheritance and the extent to which plastid transformation technology confers an increase in transgene confinement. We describe an experimental system facilitating stringent selection for occasional paternal plastid transmission. In a large screen, we detected low-level paternal inheritance of transgenic plastids in tobacco. Whereas the frequency of transmission into the cotyledons of F(1) seedlings was approximately 1.58 x 10(-5) (on 100% cross-fertilization), transmission into the shoot apical meristem was significantly lower (2.86 x 10(-6)). Our data demonstrate that plastid transformation provides an effective tool to increase the biosafety of transgenic plants. However, in cases where pollen transmission must be prevented altogether, stacking with other containment methods will be necessary to eliminate the residual outcrossing risk.
质体（叶绿体）在大多数作物中是母系遗传的。母系遗传可防止质体基因和转基因通过花粉传播。因此，质体转化被认为是确保转基因隔离和提高转基因植物生物安全性的绝佳工具。在此，我们评估了母系遗传的严格程度以及质体转化技术在多大程度上增加了转基因的隔离效果。我们描述了一个便于对偶尔发生的父本质体传递进行严格筛选的实验系统。在一个大规模筛选中，我们在烟草中检测到了转基因质体的低水平父系遗传。虽然传递到F1代幼苗子叶中的频率约为1.58×10-5（在100%异花授粉的情况下），但传递到茎尖分生组织中的频率显著更低（2.86×10-6）。我们的数据表明，质体转化为提高转基因植物的生物安全性提供了一种有效工具。然而，在必须完全防止花粉传播的情况下，有必要与其他隔离方法相结合以消除残留的异交风险。
