Biomonitoring of air pollution using antioxidative enzyme system in two genera of family Pottiaceae (Bryophyta)

Bryophyte particularly mosses, have been found to serve as reliable indicators of air pollution and can serve as bryometers–biological instruments for measuring air pollution. They are remarkable colonizers, as they have the ability to survive in adverse environments and are also particular in their requirement of environmental conditions, which makes them appropriate ecological indicators. The purpose of this study was to evaluate the activity of antioxidative enzymes in two mosses viz., Hyophila rosea R.S. Williams and Semibarbula orientalis (Web.) Wijk. & Marg. and assess their suitability as biomonitors. Three different locations viz., Lucknow University, Residency (contaminated sites) and Dilkusha Garden (reference site) within Lucknow city with different levels of air pollutants were used for comparison. Our results indicate that air pollution caused marked enhancement in activity of antioxidative enzymes viz., catalase, peroxidase and superoxide dismutase. All the three are capable of scavenging reactive oxygen species. In the genus S. orientalis, catalase, peroxidase and superoxide dismutase activity was minimum at the reference site Dilkusha Garden and was significantly higher at the two contaminated sites for catalase and peroxidase, whereas the difference was non significant for superoxide dismutase. In H. rosea the activity of catalase and peroxidase at the three locations was almost similar, however superoxide dismutase activity showed a significant increase in the two contaminated sites when compared to the reference site, the value being highest for Lucknow University site. It was thus observed that the two genera, from the same location, showed difference in the activity of the antioxidative enzymes. Based on our results, we recommend bryophytes as good monitors of air pollution. - Highlights: • In urban areas, traffic congestion leads to significant increase in air pollutants. • Adverse impact of air pollution is increased oxidative stress which activates the plants antioxidant response system. • Bryophytes were tested as biomonitors of pollution in three localities based on altered expression of antioxidative enzymes. • Bryophytes growing in polluted areas show higher activity of antioxidative enzymes as compared to reference sites. • Bryophytes can serve as suitable bioindicators of air pollution. - Role of bryophytes as passive biomonitors of the pollution level in a locality based on altered expression of antioxidative enzymes has been investigated and promising results obtained.