Cloning, Transformation and Expression of Proinsulin Gene in Tomato (Lycopersicum esculentum Mill.).

Background: Plants are among promising and suitable platform systems for production of recombinant biopharmaceutical proteins due to several features such as safety, no need for fermentation, inexpensive investment, and fast and easy scale-up. Human insulin is one of the most widely used medicines in the world. Up to now different expression systems including Escherichia coli, yeast and CHO have been exploited for producing recombinant human insulin and a variety of different recombinant insulin are extensively used.

Objectives: This study reports on the transformation and expression of proinsulin gene in tomato plants for the first time in Iran.

Materials And Methods: This study reports the cloning, transformation and expression of proinsulin gene in tomato plants. Specific primers were designed and used for PCR amplification and cloning of the proinsulin gene in the plant expression vector pCAMBIA1304. The recombinant construct was transferred into Agrobacterium tumefaciens strain LBA4404, and used for Agrobacterium mediated stable transformation of tomato plants. Presence of the desired gene in transgenic lines was confirmed through colony PCR and sequencing. The expression of the protein in transgenic lines was confirmed by immunodot blot assay.

Results: The presence of the proinsulin gene in the genomic DNA of transgenic tomato was confirmed by PCR. Also total protein of transgenic tomato was extracted and the expression of proinsulin was detected using dotblot assay.

Conclusions: This survey addresses the possibility of proinsulin gene transfer and expression in tomato transgenic lines. This study can be used as a basis for future researches to produce human proinsulin in tomato and other candidate plants.