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

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