From transgene expression to public acceptance of transgenic plants: a matter of predictability

A good strategy for acceptable legislation of transgenic plants can be thought to be composed of several stacked levels of decision-making. These levels range from global to individual to cellular to nuclear and beyond. Any decision will depend on decisions made on the level below. Various examples are given, with emphasis on the most basal level, the level of transgene expression. Plant transformation suffers from a huge variability in transgene expression. In addition, in recent years a variety of (epi)genetic transgene instabilities have been described. It is demonstrated that the addition of so-called matrix-associated regions (MARs) around transgenes before Agrobacterium-mediated transformation improves the predictability of transgene expression significantly. MARs are thought to function as boundary elements that shield the enclosed transgenes from influences of the surrounding chromatin. Assuming that such boundary elements will make transgene expression overall more predictable, this approach is then likely to contribute to a more straight-forward assessment of the biosafety of transgenic plants. This will enhance the social acceptance, hence more successful market introduction of transgenic plants.