Temporal changes of polyphenols and enzyme activities in seedlings of Kandelia obovata under lead and manganese stresses

► We investigate temporal responses of K. obovata seedlings to Pb and Mn stress. ► Phenolic compounds showed no change at Day 1 but changed at Day 7 onward. ► POD activity decreased both in root and leaf at Day 1. ► POD and SOD increased under moderate levels of Pb and Mn at Day 7 onward. ► POD activity was more sensitive to Pb or Mn stresses than phenolic compounds.