New findings on how plants fight disease could be a breakthrough in the battle against crop- killing bacteria such as Pseudomonas syringae (Psa), which has been destroying kiwifruit vines around the world, a New Zealand scientist said Monday. Massey University molecular plant biology Dr Kee Sohn said he and colleagues from New Zealand, the United Kingdom, Australia and Germany had uncovered one of the activation mechanisms that plants used to protect themselves from invading pathogens. Plants had highly specialized immune receptors within every cell that could detect the presence of molecules released by disease-causing pathogens and activate immune responses, Sohn said in a statement. The study had revealed the structure of paired immune receptors and the mechanisms by which they conferred disease resistance to important bacterial and fungal pathogens such as Psa. The two immune receptors, previously thought to work alone, joined to recognize molecules from invading organisms. After detecting pathogen-derived molecules, one of the receptors then induced immune responses such as the death of cells. "We believe that our discoveries will not only significantly enhance our understanding of plant immunity, but also help develop advanced strategies to engineer disease resistance in future crop breeding programs," Sohn said.