Road traffic emits a cocktail of pollutants that can influence the vegetation and plant diversity in neighboring areas. However, the effects of pollutants on the physiological parameters and production of plant secondary metabolites are still little explored. In this study, we compared the physiological parameters in leaves of dog rose (Rosa canina L.) at two locations – degraded site near the high frequency road (DS) and preserved meadow site isolated from traffic and direct urban impact (MS). Also, we compared the content of 45 selected phenolic compounds and antioxidant activity of leaves extract of R. canina samples collected at these two locations. Photosynthetic rate (the basic parameter of bioproduction), transpiration rate, stomatal conductance and substomatal CO2 concentration were measured in leaves of intact plants. The concentration of macroelements was determined in leaves (nitrogen by Kjeldahl's method, phosphorus by spectrophotemetric method, potassium by flame photometry). Phenolics were quantified by LC-MS-MS [1]. The assessment of antioxidant activity was done by several assays (FRAP, DPPH, NO, OH· assays and ability to inhibit lipid peroxidation). The higher transpiration rate was observed at MS (1.67 vs. 1.46 mmol H2O m-2·s-1 at DS), indicating more stabile water regime (6.22 vs. 5.76 µmol CO2 mmol-1 H2O at DS), corresponding to higher photosynthetic activity (9.60 vs. 8.43 µmol CO2 m-2 s-1) and higher bioproduction in plants at unpolluted location. The concentration of P was at the lower limit (0.09%) in plants at DS. There was no significant difference in content of 45 phenolics and antioxidant activity between two investigated sites.
References:
[1] Orčić D, Francišković M, Bekvalac K, Svirčev E, Beara I, Lesjak M, Mimica-Dukić N. Quantitative determination of plant phenolics in Urtica dioica extracts by high-performance liquid chromatography coupled with tandem mass spectrometric detection. Food Chem 2014; 143: 48 – 53
