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 SO_2, NO_2, 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.
"Air pollution effects on flavonoids in pollen grains of some ornamental plants,"
Turkish Journal of Botany: Vol. 36:
1, Article 6.
Available at: https://journals.tubitak.gov.tr/botany/vol36/iss1/6