eATP levels in APF from S. indica inoculated and mock-treated barley root samples collected at the predominantly biotrophic phase (3 and 5 dpi) as well as the predominantly cell death associated phase (7 and 10 dpi). Error bars show the standard error of the mean obtained from three independent biological replicates at p< 0.05 (*), 0.01 (**) analyzed by Student's t-test. 