Abstract
GTH4, cultured cells of interspecific F1 hybrid of N. gossei and N. tabacum, both reproductively isolated, dies at 26 C transferred from 37 C in cultures. We have shown that cell death at 26 C was controlled by quantitative balance between reactive oxygen species (ROS) and nitrogen monoxide (NO), especially presence of both NO and H2O2 were critical to initiation of cell death. Involvement of MAPK signalling in ROS generation was also verified. However, little is known about how NO generate in cell under impermissible temperature. We present here effects of inhibitors on NO generation. L-NAME, inhibitors of animal nitrogen monoxide synthetase (NOS), suppressed cell death but had no effect on extracellular NO amount. Neither NO amount nor cell death was affected by AG, inhibitor of inducible NOS. Tungstic acid, inhibitor of nitrate reductase, did not affect NO generation, but effectively reduce rate of cell death. Analysis of these inhibitors on intracellular NO amount is in progress. We further analyzed whether ROS and NO in plants act as same way as in cultured cells, and found they act as death signal in plants under quantitative balancing way.
