Transgenic trees as tools in tree and plant physiology

Abstract.

Transgenic trees are major products of tree biotechnology. This relatively young field of both plant biotechnology and tree biology concentrates on (1) improvement of pathogen, pesticide, and stress resistance, (2) manipulation of lignin content and composition, and (3) improvement of growth. Transgenic trees also have a great potential in other areas of applied and environmental research, such as in the production of phytochemicals and in phytoremediation of polluted soils. However, genetically modified trees are also excellent tools for physiological research. Transgenic trees are indispensable in investigations of the regulation of wood formation, long-distance transport, and tree growth cycles. In addition, transgenic poplars contribute significantly to our understanding of the regulation of sulfur nutrition. In this review we concentrate on the use of transgenic tree species to improve knowledge in tree and, more generally, plant physiology rather than to cover extensively the field of commercial tree biotechnology or the biological safety of transgenic plant release.