Fine Tuning Enzymes to Produce Fruits with More Flavors

By manipulating the expression of two enzymes, scientists from the University of Texas say that they can develop fruits and vegetables with improved flavors and crops with enhanced pest resistance. The enzymes—allene oxide synthase (AOS) and hydroperoxide lyase (HPL)—produce jasmonate (responsible for the unique scent of jasmine flowers) and green leaf volatiles (GLV), respectively. Plants produce jasmonate and GLVs to ward-off predators. These compounds also confer characteristic aromas to fruits and vegetables.

In the advance online publication of Nature, Raman and his colleagues reported that they were able to manipulate the flavor enzymes found in Arabidopsis thaliana by genetic engineering. The scientists made 3D images of the enzymes, which allowed them to make a small, but specific, genetic change in AOS, leading to the generation of HPL. By doing this, the scientists showed how a single amino acid substitution (point mutation) can contribute to the evolution of different biosynthetic pathways.

The paper is available to subscribers at http://www.nature.com/nature/journal/vaop/ncurrent/full/nature07307.html For more information, read http://publicaffairs.uth.tmc.edu/Media/newsreleases/nr2008/fruitflavor.htm