Plants can regain enhanced color and aroma via increased production of aromatic amino acids. Researchers at the Weizmann institute of science discovered a key regulatory enzyme of a central metabolic pathway in bacteria and expressed it in plants, obtaining transgenic plants with increased levels of secondary metabolites including higher level of aromatic amino acids.
Farmers and researches have implemented intense selective breeding in flowering plants as an attempt to improve features of decorative flowers, focusing on appearance and shelf life. Consequently, one of the most valuable qualities of the flower such as its scent and had been severely weakened. Traditional breeding is limited in its ability to supply the market demand for creating original or enhanced colors due to genetic requirements.
The innovative method can improve scent and color of decorative flowering plants without interfering with other natural mechanisms of the plant.
- Improved esthetical value due to strong color and pleasant scent to ornamental flowers.
- The color and scent of flowers has an additional eco-systematic role in the reproduction of fruits. Manipulating both color and odor may allow future optimized ability the repulse insects or attracts pollinators.
- This method can be applied not only to enhance naturally existing color but also for the recently commercialized production of new colors of plants. For example flavonoid biosynthesis which was shown to be enhanced by this method was also found to be highly relevant in generating unique flowers colors
- Enhanced fragrance and colors utilizing natural metabolic pathways of flowering plants.
- No breeding and selection required to enhance flowers traits.
- Endogenous integration between bacteria and plant that involves no interference with other natural mechanisms in the plants.
Researches at Prof. Gad Galilis lab elicited a significant increase in the direct products of the shikimate pathway and in the aromatic amino acid Phenylalanine.
A central regulator in the shikimate pathway is the first committed enzyme of the pathway; 3-deoxy-D-arabino-heptulosonate 7-phosphate synthase (DAHPS). The bacterial DAHPS is feedback inhibited by a separate amino acid. At the core of this technology is the dominant isoform that is the AroG gene which is under the regulation of Phenylalanine and responsible for 80% of the total DAHPS activity.
By expressing a mutant bacterial AroG gene encoding a feedback insensitive DAHPS in transgenic Arabidopsis plants, researchers achieved increased levels of the shikimate direct metabolites, products and aromatic amino acids. Detailed analysis revealed that while no metabolite exhibited decreased levels in the transgenic plants, the levels of shikimate intermediate metabolites, phenylalanine, tryptophan, and a verity of secondary metabolites (such as auxin and hormones conjugates) were increased by the mutant bacterial gene.