A Synthetic Green Fluorescent Protein Gene for Plant Biotechnology.

Abstract

Since Green Fluorescent Protein (GFP) from Aequorea jellyfish emits green fluorescence without any additional substrates or co-factors, it has emerged as a powerful new reporter for use in a variety of organisms. However, improvements such as the alteration of the excitation spectrum and the elimination of a cryptic intron site were necessary for its efficient use in plants. An engineered synthetic GFP with a S65T mutation (replacement of the serine in position 65 with a threonine) in the chromophore has provided up to 100-fold brighter fluorescent signals than the wild-type jellyfish GFP sequence without any toxic effects. The sGFP(S65T) has been widely used for studies such as localization analysis and promoter assays. This sGFP(S65T) is also an ideal candidate for the development of transformation methods for crops and trees in which it has previously proved difficult to obtain transformants via conventional methods. A non-invasive, quantitative detection technique for this GFP has been achieved in conjunction with a fluorescent imaging system.