When harmful insects attack a plant, it defends itself. It forms protective substances that are poisonous for the insects. This defense response is activated by messengers, jasmonates. Their biosynthesis had been deemed to have been elucidated for almost two decades. But now plant physiologists from the University of Hohenheim in Stuttgart and the National Center for Biotechnology (CNB-CSIC) in Madrid have found an alternative synthesis pathway for jasmonates. This means that plant physiologists will now have to rethink many explanations of resistances and hormonal activity. The researchers have published their findings in the scientific journal Nature Chemical Biology.