The green fluorescent protein (GFP) as a vital screenable marker in rice transformation

An engineered green fluorescent protein (GFP) from the jellyfish Aequora victoria was used to develop a facile and rapid rice transformation system using particle bombardment of immature embryos. The mgfp4 gene under the control of the 35s Cauliflower Mosaic Virus promoter produced bright-green fluorescence easily detectable and screenable in rice tissue 12-22 days after bombardment. Visual screening of transformed rice tissue, associated with a low level of antibiotic selection, drastically reduced the quantity of tissue to be handled and the time required for the recovery of transformed plants. GFP expression was observed in primary transformed rice plants (T-0) and their progeny (T-1). We describe various techniques to observe GFP in vitro and in vivo. The advantages of this new screenable marker in rice genetic engineering programmes are discussed.