Catalyzes the oxidation of aldehydes to the corresponding carboxylate by coupling the reaction to the reduction of dioxygen to hydrogen peroxide. Substrates include glyoxal and other aldehydes (By similarity). May be regulated by the transcription factor MYB80 during anther development and play a role in tapetum and pollen development (PubMed:21673079). an aldehyde + H2O + O2 = a carboxylate + H(+) + H2O2 During anther development, expressed from stage 10 to the latest stage 14 in tapetal cells, developing microspores and mature pollen grains and released pollen grains.