2018 ASHS Annual Conference

Gaseous nitrogen dioxide (NO₂) can disturb normal plant growth and trigger complex physiological response. In this study, we investigated epidermis and stomata related physicochemical responses of Carpinus putoensis leaves when exposed to NO₂ (6 ml/l) for seven time periods (0, 1, 6, 12, 24, 48, and 72 h) and 30 d of recover without NO₂ exposure. Our results showed that NO₂ exposure for 72 h led to the decline of chlorophyll content, maximal PSII quantum yield (Fv/Fm), net photosynthetic rate (Pn) compared with the control and other exposure time. Moreover, NO₂ exposure significantly increased the thicknesses of palisade/spongy tissue, caused swelling of the thylakoids within the chloroplasts, this thylakoid swelling could be reversed by removing the pollutant from the air flow. Recovery alleviated NO₂-caused toxic effects as indicated by increased chlorophyll content, and high values of Pn and Fv/Fm. This result could provide a reference of recovering method when road greening trees exposed to NO₂ as the road main pollutants.

Gaseous nitrogen dioxide (NO₂) can disturb normal plant growth and trigger complex physiological response. In this study, we investigated epidermis and stomata related physicochemical responses of Carpinus putoensis leaves when exposed to NO₂ (6 ml/l) for seven time periods (0, 1, 6, 12, 24, 48, and 72 h) and 30 d of recover without NO₂ exposure. Our results showed that NO₂ exposure for 72 h led to the decline of chlorophyll content, maximal PSII quantum yield (Fv/Fm), net photosynthetic rate (Pn) compared with the control and other exposure time. Moreover, NO₂ exposure significantly increased the thicknesses of palisade/spongy tissue, caused swelling of the thylakoids within the chloroplasts, this thylakoid swelling could be reversed by removing the pollutant from the air flow. Recovery alleviated NO₂-caused toxic effects as indicated by increased chlorophyll content, and high values of Pn and Fv/Fm. This result could provide a reference of recovering method when road greening trees exposed to NO₂ as the road main pollutants.