Impact of heavy metals on physiological processes of plants: With special reference to photosynthetic system

Abstract

Heavy metal pollution is one of the major environmental problems which is caused by unchecked and uncontrolled discharge of hazardous chemicals consisting of heavy metals. Heavy metals affect agricultural land and plant’s productivity by affecting its most vital process, i.e., photosynthesis. Exposure of plants to heavy metals leads to generation of ROS, and few heavy metals are directly involved in electron transport. It also leads to lipid peroxidation destroying plant’s cell membrane and its associated organelles. Chlorophyll biosynthesis is affected by heavy metals as it substitutes Mg ion from chlorophyll. Few heavy metals also affect enzyme involved in chlorophyll biosynthesis as well as disturb electron transport in light reactions and affect various enzymes in dark reactions. This detailed information helps us to understand the mechanism linked with the impact of heavy metals on physiological responses affecting plant biomass and productivity which is of concern for agriculture. Therefore, the present chapter consists of whole information regarding the impact of heavy metals on photosynthetic pigments, photosynthetic apparatus, and light and dark reactions.