Studies on the biosafety assessment of transgenic plants(3/4)

We have produced transgenic Eucalyptus camadulensis carrying the Populus tremuloides cinnamate 4-hydroxylase(C4H) gene. These transgenic plants are obtained by Agrobacterium-mediated transformation in which the transgene is driven by the 35S promoter. No evidence exists for gene transfer from plants into microorganisms or for horizontal gene movement. Escape through tree naturalization and escape through hybridization can be much more a problem. One of the most discussed environmental effects associated with the use of transgenic trees is the loss of control over the engineered genes. Flowering and pollen dispersal are important for outcrossing of the genetically engineered trait. An escape of transgenes is commonly by pollen because it is a major element of the reproductive system that is designed for gene movement. The biosafety assessment will be carried out successively in semi-containment greenhouse and isolated field trials. The most important step is to fully understand the characterization of the GM plant and the function and mechanism of the trangenes. The aim of this study is to determine the gene movement by self-pollination in a transgenic tree of E. camadulensis. In addition to these, gibberellins and cytokinins are the plant growth substances most likely to be closely implicated in at least several aspects of the flowering process. However, changes in endogenous gibberellins and cytokinins during flower development remain essentially unknown, especially in Eucalyptus camadulensis. The content of endogenous gibberellin and cytokinin in Eucalyptus camadulensis at vegetative growth, early floral initiation, and flower development stages will be investigated. We will also determine the influence of paclobutrazol treatment on the shoots at different development stage in relation to floral initiation.