Strategies to deal with the concern about marker genes in transgenic plants: Some environment-friendly approaches [Review]

摘要

Selectable marker genes, that confer resistance to antibiotics or herbicides, are generally incorporated along with the gene of interest in a transformation process so as to allow the recognition of the transformed cells from a background of untransformed ones. Subsequent to the generation of transgenic plants, the presence of these marker genes becomes no more of practical utility and thus arguably a matter of public euphoria, speculating the risk they can pose to the environment and health. Since the recurrent transformations to pyramid desirable genes are practically difficult with the same selectable markers used, novel strategies evolved to essentially eliminate these marker genes or to modulate their spatial/temporal expression, and by use of environmentally safe selectable markers and transplastomic plants. The article discusses the state-of-the-art applications and limitations associated with such systems.