High-Lysine Corn Generated by RNAi

Lysine is one of the most limiting amino acids in plants consumed by humans and livestock. In corn, among other crops, synthetic supplements are being added to increase its lysine content. A group of scientists from Monsanto reported that they were able to obtain transgenic maize with increased lysine concentration in its kernels using RNA mediated interference (RNAi).

In RNAi, gene expression, in this case a gene coding for the enzyme responsible for lysine degradation, is inhibited by introducing double stranded RNA with base sequences complementary to the gene of interest. The team proved that lysine catabolism and not its biosynthesis impacts lysine accumulation in corn grains.

Their study showed that unlike traditional breeding, wherein improved traits are often recessive and lack tissue specificity, RNAi offers a more useful technology to down-regulate the expression of endogenous genes in a dominant and specific manner.

For details, the paper published by the Plant Biotechnology Journal can be accessed by subscribers at http://www.blackwell-synergy.com/doi/full/10.1111/j.1467-7652.2007.00265.x