TJ1 is an orientation-independent transformation enhancer sequence

Abstract

A 507-bp nuclear matrix attachment region (MAR) sequence (designated TJ1) was flanked at both at 5′ and 3′ ends of the expression cassette for a modified green fluorescent protein (GFP) gene of the 35 Ω-sGFP(S65T) in four different orientations. A plasmid p507TH bearing a 507-bp non-MAR sequence from yeast at both ends of the cassette also was constructed. These five plasmids and 35 Ω-sGFP(S65T) were separately delivered into cultured tobacco BY-2 cells by particle bombardment. The yield of stable transformants that showed a uniform green fluorescence was determined. Southern blot analysis confirmed the integration of the GFP gene in tobacco genome. Transformant yields of the two TJ1-lacking plasmids were not significant. Transformant yields appeared to be increased by more than 2 times by the presence of TJ1-MAR sequences. The orientation of TJ1-MAR sequences did not influence the transformant yield.