Current status of the development of genetically modified (GM) forest trees world-wide: a comparison with the development of other GM plants in agriculture.

Abstract

Abstract Agricultural crops that are genetically improved via recombinant DNA and asexual gene transfer techniques have been commercialized since 1996 and widely planted; currently, 'biotech crops' cover c.170 million ha, i.e. 11% of the total managed cropland globally, and represent a world-wide market value of c. US$15 billion, with an estimated tenfold return from the final product. This situation is in strong contrast to the almost complete lack of commercial deployment of genetically engineered (GE) forest trees (with the only exception being GE poplars commercially grown in China). Reasons for this discrepancy are the low-social acceptance of GE tree deployment, because of the perceived uncertainties about long-term risks for the natural forests that such plantations could cause, and the public demand for absolute transgene containment which is difficult to engineer without generating pleiotropic effects. In this review, we present the status quo of agricultural crop biotechnology with a special focus on GE trees. In the near future, the forestry sector will need to meet the increasing demands for timber and improved feedstock with regards to value-added products made out of lignocellulosics. GE in economically important forest trees can accelerate the domestication of these long-lived plant species in terms of high productivity. At the same time, the pressure should decrease on harvesting natural forest stands, which should remain unmanaged conservation forests for biodiversity preservation.