Physiological Response of Indoor Plants according to Formaldehyde Concentrations

Physiological response of indoor plants was investigated according to formaldehyde concentrations. Epipremnum aureum, Fatsia japonica, and Rhapis exelsa were exposed 0, 2(2.5), 10(12.3), 100(123) ppm(mgㆍm⁻³)of formaldehyde. Necrosis was a visible injury symptom in leaves and stem with exposure to 100 ppm formaldehyde for 5 h. Apparent injury appeared in young and old leaves of every plant, but displayed in stems of only Fatsia japonica. Cells in tissue of injury leaves were altered or demolished, and resulted in destruction of palisade and spongy parenchyma. Peroxidase and catalase content were highest in R. exelsa but lowest in E. aureum. Catalase activity increased with increasing formaldehyde concentrations. Stomata of E. aureum that was severely damaged in leaves closed up to 80% with exposing 100 ppm of formaldehyde, and catalase activity of E. aureum increased highest. As a result, stomata were closed and enzyme activity were changed in order to become tolerance when indoor plants were exposed in high concentration of formaldehyde, while it was not showed in low concentration of formaldehyde.