By studying how plants change their production of amino acids in response to a simulated attack, scientists at the DOE's Brookhaven National Lab have uncovered clues that may help engineer more pest-resistant crops and feedstocks that are easily convertible to ethanol, a burnable biofuel. The scientists were studying the effects of jasmonate when insects start chewing on a leaf. The Brookhaven team was particularly interested in understanding the role jasmonate plays in altering the composition of cell walls - structures comprised primarily of polysaccharides such as cellulose and hemicelluloses and other complex macromolecules such as lignin. Using a radioactive form of nitrogen (13N) as ammonia gas, they recently developed a way to rapidly infuse radiotracer into intact plant leaves and follow the uptake of labeled nitrogen into amino acids, the building blocks of proteins. The technique revealed increased movement of amino acids away from mature leaves into younger, developing leaves and roots shortly after jasmonate treatment. Most significantly, the team detected increased production of the amino acids glycine and serine in response to jasmonate.