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.