Figure 4. Involvement of SLAC1 in the regulation of cryptogein-induced biphasic ROS production mediated by NADPH oxidases.

(A) Cryptogein (0.25 µM)-induced rapid transient ROS production within 15 min in BY-2 cells. Data is representative of three experiments (B) The effects of inhibitors on cryptogein-induced ROS production within 15 min. To quantify the effects of inhibitors on ROS production, the peak intensity of luminol chemiluminescence was compared with the control. DIDS or an NADPH oxidase inhibitor, DPI, was added to BY-2 cells 15 min prior to the elicitor treatment. DMSO was used as a control. Data are the mean ± SE of three independent experiments. ** p<0.005, significantly different from the control line. (C) Effect of SLAC1-overexpression on cryptogein-induced prolonged ROS production. BY-2 cells were treated with cryptogein (0.25 µM). Data are the mean ± SE of three independent experiments. * p<0.05, ** p<0.005, *** p<0.001, significantly different from the control line. (D) Quantitative expression levels of NtRbohD mRNAs in SLAC1-overexpressing cells by real-time quantitative PCR. Total RNA was isolated from BY-2 cells harvested 5 h after the addition of cryptogein at various concentrations. The amount of each mRNA was calculated from the threshold point located in the log-linear range of the RT-PCR. The relative level of each gene in the control cells at time 0. Data are the mean ± SE of four independent experiments. * p<0.005, ** p<0.005, significantly different from the control line.