Photosythetic responses of two salt-tolerant plants, Tamarix gallica and Arthrocnemum indicum against arsenic stress: A case study

Abstract

In recent years, the level of arsenic in soil has increased dramatically in many countries, which has raised concern to develop new environmentally friendly techniques to solve problems such as arsenic, which is highly soluble and has toxic effects. It is an environmental issue and a global health matter because of its poisonous and carcinogenic characteristics. It is known that arsenic influenced farmland and plant productivity by disturbing their most essential activity like photosynthesis. Plants subjected to arsenic cause reactive oxygen species' (ROS') generation and engender lipid peroxidation leading to plant cell membrane destruction and its connected component replacing chlorophyll's Mg ion through which arsenic affects chlorophyll biosynthesis and therefore altering the enzyme involved in chlorophyll biosynthesis, electron movement disruption in light mechanism, and influencing several enzymes in dark reactions. Plants subjected to arsenic show a loss in photochemical efficiency and photosynthetic electron movement indicated by parameters of chlorophyll fluorescence. "This type of photosynthetic response indicates the physiological state of the whole plant organism. Therefore, the change in photosynthetic activity assessed by chlorophyll fluorescence represents one of the most reliable and useful physiological biomarkers for the detection of toxic effects of pollutants. This leads us to determine the mechanism related to the arsenic (As) impact on physiological feedback altering plant weight and fruitfulness, inhibition of the chlorophyll biosynthetic or degradation pathway and may lead to dysfunction of plants. Therefore, this chapter contains comprehensive data in relation to the arsenic incidence on photosynthetic pigments, the photosynthetic status, and reactions to light and dark. Thus, the study looked at the incidence of metabolic stress with or without salt stress on the content of photosynthetic pigments, namely chlorophylls a and b and carotenoids and further on the photosynthetic apparatus.