Mechanism of Arsenic Toxicity and Tolerance in Plants: Role of Silicon and Signalling Molecules

Abstract

Arsenic (As) contamination is a major environmental problem. It has become a major limiting factor in the growth and yield of crop plants, affecting the sustainability of agriculture production. Arsenic taken up by the plant tissue causes severe damage to important cellular components, such as lipids, protein, DNA and RNA. Mostly, inorganic forms of As, arsenate and arsenite, are found to be more toxic. To mitigate and reduce the negative effects of As, various prospects have been evaluated. Silicon (Si) has been found to serve as a beneficial element for plant growth and development, and its accumulation is helpful in maintaining sustainable production. Studies have revealed the ability of Si to mitigate various biotic and abiotic stresses in crop plants. It is also known that phosphate transporter recognizes arsenate while arsenite is taken up as a Si transporter. There is a lack of information available on the interactive effects of As and Si, especially in terrestrial or crop plants. On the other hand, signalling molecules are also known to regulate plant metabolism, growth and development under various stresses. The signal pathways either operate independently or may positively or negatively modulate other pathways. This chapter examines the participation and interaction of As and Si in plants. Furthermore, role of signalling molecules is also discussed to mitigate As-induced damages.