Figure 4.

Effect of Ca²⁺ chelator (EGTA) on cytosolic Ca²⁺ fluorescence intensity in NPPB-treated tea roots. Control, NPPB and EGTA indicate distilled water, 50 µM NPPB, and 1 mM EGTA for 0.5 h respectively; EGTA + NPPB refers to tea roots were placed in 1 mM EGTA for 0.25 h, then subjected to a direct 50 µM NPPB for 0.5 h; Ca²⁺ fluorescence was determined after control, NPPB, EGTA and EGTA + NPPB treatment in tea lateral roots. Data indicate mean ± SD (n = 4). Error bars indicate difference among the treatments and different low case numbers near the chart bars indicate the level of significance as compared with control at p < 0.05.