Phenolic compounds function as stress indicators because they accumulate to high levels in many plant tissues in response to a wide range of biotic and abiotic signals. These compounds are involved in pollen development, pollination, pollen germination, and pollen tube growth. | F. REZANEJAD Research Article Turk J Bot 36 (2012) 49-54 © TÜBİTAK doi: Air pollution effects on flavonoids in pollen grains of some ornamental plants Farkhondeh REZANEJAD* Department of Biology, Shahid Bahounar University, Kerman - IRAN Received: Accepted: Abstract: Phenolic compounds function as stress indicators because they accumulate to high levels in many plant tissues in response to a wide range of biotic and abiotic signals. These compounds are involved in pollen development, pollination, pollen germination, and pollen tube growth. The mature pollen grains of Spartium junceum L., Lagerstroemia indica L., Thuja orientalis L., and Petunia hybrida L. collected from control (less polluted) and polluted areas [mainly SO2, NO2, CO, hydrocarbons (HC), and airborne particulate material (APM)]. The ethanolic aquatic extracts of pollen grains were prepared. The extracts were analysed by high pressure liquid chromatography (HPLC). HPLC analysis demonstrated that air pollution induces flavonoids accumulation to significantly higher levels in the polluted pollen of Spartium junceum, Lagerstroemia indica, and Thuja orientalis than in the controls. In Petunia hybrida the flavonoids level increased more slightly in the pollen grains exposed to air pollutants compared to controls. Key words: Air pollution, flavonoids, ornamental plants, pollen Introduction Increase in the levels of air pollution due to the increase in industrial and agricultural technology has prompted investigation of the mechanisms that contribute to air pollution tolerance in plants. The quality of the air is now monitored daily in sensitive areas by numerous organisations specialising in air quality control (Bortnick & Stetzer, 2002). However, the impact of the various atmospheric pollutants on living organisms remains a poorly understood phenomenon. Observation of the reactions of a living organism exposed to air pollution under natural conditions is .
