Abstract
Adenosine 5'-triphosphate (ATP) involved in many cellular biological processes. It has been known that concentration of intracellular ATP ([ATP]i) is decreased with time after induction of cell death in plant, suggesting that the reduction of [ATP]i might lead to activation of cell death pathway in plants. To further investigate possible involvement of ATP in the plant cell death, we tried visualization of [ATP]i dynamics in live plant at single cell level by using a FRET-based ATP indicator, ATeam, which has been recently developed by us. We examined whether pathogen-induced hypersensitive cell death (HCD) is associated with reduction of [ATP]i in Arabidopsis plants. When the plant was inoculated with virulent bacteria, the [ATP]i did not changed. On the other hand, inoculation of avirulent bacteria induced small [ATP]i reduction, which preceded the changes in morphological features of HCD, and then the reduction of [ATP]i still continued after the morphological changing. This result raised two opposing possibilities, i.e., small reduction of [ATP]i is essential to activate cell death pathway in HCD, or ATP is not involved in HCD.
