We detected 5-LOX (arachidonate 5-lipoxygenase) in the homogenate of Marchantia polymorpha by spectrophotometry and mass spectrometry. LC/MS/MS analysis indicated that the liverwort 5-LOX produced 5-hydroperoxy-6,8,11,14-eicosatetraenoic acid (5-HPETE) with arachidonic acid as a substrate. The 5-LOX activity showed a Ca2+ response, as demonstrated for human 5-LOX. These findings suggest that the liverwort utilizes an arachidonate cascade in a defense signal response.
