Expression of an environmentally friendly synthetic protein-based polymer gene in transgenic tobacco plants

We report the expression of a protein-based polymer (Gly-Val-Gly-Val-Pro)121, i. e., (GVGVP)121 in transgenic tobacco (Nicotiana tabacum var. Kentucky 17) plants. The plant expression vector pBI121-XZ-120mer which contains the gene (GVGVP)121 with a prokaryotic preferred codon composition driven by the CaMV 35S promoter was introduced into tobacco plants byAgrobacterium-mediated transformation. Stable integration of the (GVGVP)121 polymer gene was confirmed by Southern blot analysis. Northern hybridization showed polymer transcripts in leaves of transgenic plants. The (GVGVP)121 polymer protein was detected in leaves of transgenic plants by Western blot. The (GVGVP)121 protein could be easily purified to a high degree of purity from leaves of transgenic plants by reversible phase transition as revealed by SDS-PAGE gels stained by CuCl2. Transgenic plants grew, flowered, and produced seeds normally.