Jasmonate,act as insect herbivore and wounding related plant hormone,play pivotal roles in plant defense and development.However,the mechanism of plant defense induced by MeJA remains unclear.Our studies preliminary reveals the regulation relationship between PM H⁺-ATPase and H₂O₂ accumulation.We showed that:MeJA activated the PM H⁺-ATPase firstly,which resulted the H⁺ efflux out of cell and cytosolic alkalinization.Further,the increase of cytosolic pH activated the NADPH oxidase,which promoted the accumulation of H₂O₂.These results suggested that the accumulation of H₂O₂ were regulated by PM H⁺-ATPase,which would benefit plants for defending against insect attack and pathogen infection.