“…Two lectin receptor kinases, P2K1 and P2K2, were identified to be eATP receptors in Arabidopsis thaliana [ 19 , 20 ] involved in eATP-induced immune responses [ 13 , 14 , 21 ]. Signal transducers in the plasma membrane (PM), including heterotrimeric G proteins [ 12 , 22 ], NADPH oxidase [ 23 , 24 ], and Ca 2+ channels [ 6 , 23 , 25 , 26 ], were reported to be involved in eATP signal transduction. Several secondary messengers, e.g., ROS, H 2 O 2 , NO, and Ca 2+ may be responsible for the eATP-induced intracellular responses that eventually alter plant growth and development [ 6 , 17 , 26 , 27 , 28 , 29 ].…”