Scientific research related to genetically modified trees
Résumé
Over the last decade, we have witnessed impressive advances in tree molecular biology and the consolidation of tree genomics. We have essentially moved from a small portfolio of genes focusing on a specifi c genetic trait to large databases including thousands of genes and their respective expression profi les. In 2006, we saw the publication of the fi rst genomic sequence of a tree, the model tree species Populus trichocarpa . Though, not surprisingly, much progress has been made with Populus, impressive research results have also been realized in more recalcitrant coniferous species such as pines and spruces.
Despite the rapid advances in tree genomics, tree genetic engineering (GE) proved to be a bottleneck requiring the development of whole-tree regeneration protocols using in vitro culture and an effective method of DNA transfer. The introduction of simple single gene traits such as insect resistance was the early target of
tree genetic engineers. Today more tree species are compatible with GE and at a higher throughput, making functional genomics approaches possible to improve our understanding of gene functions.
In this chapter we will provide an historical overview of the advances made in GE of trees. We will also explore the various applications of tree GE to improving response to biotic and abiotic stresses, which is becoming more important in an ever-changing environment. Improvement of specifi c traits for tree domestication will also be covered. Lastly, we will briefl y discuss issues related to the regulation of GM trees, particularly concerning genetic containment and environmental risk assessment.