Abstract:

【Objective】 To improve the expression of immunoreactive thymosin alpha 1(Tα1) protein in tomato plants.【Method】 The Tα1 gene was designed and synthesized according to the plant codon usage bias, then created a novel Tα1 concatemer that four copies of Tα1 gene were arranged end-to-end in tandem. Recognition site sequence of enterokinase was inserted between single Tα1 gene, so that fusion protein could be cut by enterokinase. Subsequently, Tα1 gene and Tα1 concatemer were respectively introduced into tomato via Agrobacterium tumefaciens mediated transformation. 【Result】 After the two genes transformation, 19 and 10 regenerated tomato plants resistant to kanamycin were obtained. Some of transgenic tomato plants were further confirmed by polymerase chain reaction (PCR) and Southern blot. Western blot analysis showed the expression of Tα1 concatemer protein in transgenic tomato fruits. The enzyme-linked immunosorbent assay (ELISA) analysis showed that the content of the Tα1 concatemer protein was equal to 20.2 μg Tα1?g-1 fresh weight in mature tomato fruit, which was higher than the expression of Tα1 gene. 【Conclusion】 The expression of Tα1 protein had increased in tomato by gene repeats.

Key words: thymosin alpha 1')">thymosin alpha 1, transgenic tomato, bioreactor, gene repeat, enterokinase