Abstract
Green fluorescent protein (GFP) has been widely used for monitoring gene expression and protein localization in diverse organisms. However, highly sensitive imaging equipment like fluorescence microscope is usually required for the visualization of GFP, which limits its application to fixed locations with specific samples. A reporter that can be visualized in real time regardless the shape, size, and location of the target samples will make research work much more flexible and efficient. Here, we report the application of a GFP-like protein, called eYGFPuv, to both transient expression and stable transformation in two herbaceous plant species (Arabidopsis and tobacco) and two woody plants (poplar and citrus). We observed strong fluorescence under UV light in all of the four plant species without any effects on plant growth or development. eYGFPuv was shown to be very effective for visualizing transient expression in leaf and root tissues. With a focus on in vitro transformation, we demonstrated that the transgenic events expressing eYGFPuv could be easily identified by naked eyes during callus stage and shoot stage, which enables early and efficient selection of transformants. Furthermore, whole plant level visualization of eYGFPuv revealed its genetic stability in transgenic plants. In addition, our transformation experiments showed that eYGFPuv could be used for antibiotic-free selection of transgenic plants. Our work demonstrates the feasibility of employing eYGFPuv in studies of gene expression and plant transformation in diverse plants.
