Effect of 14% H₂O₂ on the leaf discs of NtSAT4 single and double overexpression lines. Leaf discs from three compartment-specific single overexpressor lines cytosolic (C), mitochondrial (M), and plastidic (P) and double overexpressor lines mitochondrial×plastidic (M×P) and mitochondrial×cytosolic (M×C) lines and wild-type plants treated with 14% H₂O₂ for 24 hours. Scale bar = 1 cm.