Fusion of the transposase with a classical nuclear localization signal to increase the transposition efficiency of Ac transposon

A new strategy was applied to improve the transposition efficiency of the maize transposon Activator (Ac) in heterologous plants. The Ac transposase was fused with a classical nuclear localization signal (NLS) of SV40 to promote the transport of transposase into a nucleus. Base on this, two NLS-TPase constructs were yielded, one containing the full length transposase gene (termed as SV40TPase), the other containing the truncated transposase gene (lacking its first NLS-like signal, termed as SV39TPase). These two NLS-TPase genes were expressed in transgenic tobacco plants under the control of PR-1a promoter. Excision of non-autonomous transposable element (Ds) from luciferase (LUC) reporter gene constructs was employed to analyze the induction of Ac transposase containing NLS. Applying the LUC assay and PCR analysis, these new NLS-TPase sources triggered higher Ds excision efficiencies then the native transposase. Furthermore, the SV40TPase showed more ability then the SV39TPase to trigger the Ds element. The usage of this new inducible transposon for plant functional genomics is discussed.