Activities of caspase3-like protease in root tip cells treated by 100 μM AlCl
for 0, 4, 8 and 12 h in 99-1507 and ZH2. Caspase3-like protease activity was expressed as the absorbance in 405 nm. Data represent the mean (±SD) of three independent measurements. ** means significance at P < 0.01 ( Student’s t test) in 99-1507 compared with ZH2.