Figure 3.

ROS generation process and localization in plant cells. In different cell organelles, ROS are produced through metabolic reactions where different enzymatic and non-enzymatic pathways are involved. ROS—reactive oxygen species; H₂O₂—hydrogen peroxide; ¹O₂—singlet oxygen; ETC—electron transport chain; ^•OH—hydroxyl radical; ³Chl*—triplet chlorophyll; PS I—photosystem I; PS II—photosystem II; O₂^•−—superoxide anion; XOD—xanthine oxidase; SOD—superoxide dismutase; NADPH—nicotinamide adenine dinucleotide phosphate; UO—urate oxidase [24].