Air pollutants and photosynthetic efficiency of plants

Abstract

Absorption and accumulation/integration of air pollutants by leaves induce physiological and biochemical alterations in plants. Photosynthesis is the basic physiological event affected in plants exposed to air pollutants. Reduction in leaf area, closure of stomata and the damage to the photosynthetic apparatus limit the photosynthetic capacity of plants. High concentrations of sulphur dioxide (SO2), ozone (O3) and nitrogen oxides (NOx) induce stomatal closure limiting the availability of carbon dioxide (CO2) for photosynthesis. Reactive oxygen species (ROS) generated during oxidative stress damage photosynthetic apparatus via alteration in thylakoid structure and function. The photosynthetic electron transport, carboxylation efficiency of RuBisco and chlorophyll biosynthesis are the major processes negatively affecting the photosynthetic efficiency of plants.