GFP in plants

There are two major uses for green fluorescence protein (GFP) in plants: monitoring gene expression and protein localization at high resolution, and providing an easily scored genetic marker in living plants. GFP can be used as a replacement for beta -glucuronidase, which is commonly used as a reporter for genetic fusions in plants. It allows direct imaging of the fluorescent gene product in living cells without the need for prolonged and lethal histochemical staining procedures. In addition, GFP expression can be scored easily using a long-wave UV lamp if high levels of fluorescence intensity can be maintained in transformed plants. An assay for gene expression using fluorescence in vivo would be a very useful tool for plant transformation and breeding experiments. To employ GFP successfully in plants, three major steps need to be taken: (1) The GFP apoprotein must be produced in suitable amounts in the plant cells. (2) The apoprotein must undergo efficient post-translational cyclization and oxidation to produce the mature GFP (Ref. 2). (3) The fluorescent protein may need to be suitably targeted within the cell, to allow efficient post-translational processing, safe accumulation to high levels, or to facilitate detection of expressing cells.