2.3.3 H2O2 Content
Hydrogen peroxide content (H2O2) content was determined using a modified method of Velikova et al. (2000).S. hieraciifolia and T. parvula samples were extracted with 5 % cold TCA (w/v) with activated charcoal. After the extract was centrifuged, 10 mM potassium phosphate (K2HPO4) buffer (pH 7.0) and 1 M potassium iodide (KI) were added to 1 ml supernatant. The absorbance was then read at 390 nm.