A hidden second option plants have for making an essential amino acid that could be the first step in boosting plants' nutritional value and improving biofuel production potential, has been discovered by scientists at Purdue University, it was announced today (31st March). The amino acid phenylalanine is required to build proteins and is a precursor for more than 8,000 other compounds essential to plants, including lignin, which allows plants to stand upright but acts as a barrier in the production of cellulosic ethanol.