Seed-specific expression of the isopentenyl transferase gene (ipt) in transgenic tobacco

The Agrobacterium tumefaciens gene encoding isopentenyl transferase (ipt), a cytokinin biosynthetic gene, was fused to a promoter from a seed-specific gene, vicilin, and introduced into tobacco cells. Intact fertile plants were generated. The expression of the vicilin-ipt gene was shown to be confined to seed and resulted in enhanced levels of cytokinins in the developing seeds and increased seed protein content. Using a simplified quantification method, a significant increase in the levels of endogenous cytokinins was recorded at 16–21 days after flowering. The growth of the transgenic plants and the development of the seeds appeared to be normal.