Abstract

Environmental contamination with arsenic (As) is a global environmental, agricultural and health issue due to the highly toxic and carcinogenic nature of As. Exposure of plants to As, even at very low concentration, can cause many morphological, physiological, and biochemical changes. The recent research on As in the soil-plant system indicates that As toxicity to plants varies with its speciation in plants (e.g., arsenite, As(III); arsenate, As(V)), with the type of plant species, and with other soil factors controlling As accumulation in plants. Various plant species have different mechanisms of As(III) or As(V) uptake, toxicity, and detoxification. This review briefly describes the sources and global extent of As contamination and As speciation in soil. We discuss different mechanisms responsible for As(III) and As(V) uptake, toxicity, and detoxification in plants, at physiological, biochemical, and molecular levels. This review highlights the importance of the As-induced generation of reactive oxygen species (ROS), as well as their damaging impacts on plants at biochemical, genetic, and molecular levels. The role of different enzymatic (superoxide dismutase, catalase, glutathione reductase, and ascorbate peroxidase) and non-enzymatic (salicylic acid, proline, phytochelatins, glutathione, nitric oxide, and phosphorous) substances under As(III/V) stress have been delineated via conceptual models showing As translocation and toxicity pathways in plant species. Significantly, this review addresses the current, albeit partially understood, emerging aspects on (i) As-induced physiological, biochemical, and genotoxic mechanisms and responses in plants and (ii) the roles of different molecules in modulation of As-induced toxicities in plants. We also provide insight on some important research gaps that need to be filled to advance our scientific understanding in this area of research on As in soil-plant systems.

Highlights

  • Contamination of air, soil, and water resources with potentially toxic elements (PTEs) is a global environmental issue [1,2]

  • Livanos et al [216] reported that several root cells of a mutant Arabidopsis thaliana (RHD2), which lacks the RHD2/AtRBOHC protein function, exhibited aberrations, compared to those induced by low reactive oxygen species (ROS) levels

  • Singh et al [196] observed higher accumulation of MDA in Pteris ensiformis than that of Pteris vittata and suggested that Pteris vittata was able to maintain homeostatic control over photosynthetic light reactions under As stress. This entails that Pteris vittata could not produce more ROSs and as such resulted in a low amount of MDA generation

Read more

Summary

Introduction

Contamination of air, soil, and water resources with potentially toxic elements (PTEs) is a global environmental issue [1,2]. In the soil and water environments, As can exist in four different oxidation states: As(-III), As(0), As(III), or As(V) [16] Both organic (e.g., monomethyl arsonic acid, arsenobetaine, and arsenosugars) and inorganic species of As are present, the latter being more toxic and mobile than organic As species. Among non-enzyme antioxidants, proline is a well-known osmoprotectant that is largely accumulated in plants under As stress [6,32,47] It serves as a cell wall plasticizer and helps maintain a minimum level of hydration needed for the normal functioning of cell and protects plants against ROS-mediated damages [22,32,48,49]. The protective role of the exogenous supplies of proline, SA, NO, and Pi for plants under As stress are addressed

Arsenic Content in Soil
Arsenic Concentration in Water
Speciation of Arsenic in Soil
Translocation of Arsenic from Soil to Plant
Uptake
Uptake and Transport of Organic Arsenic Species
Arsenic Transporters in Plants
Effect of of Arsenic
Arsenic
Impact of Arsenic on Photosynthesis of Plants
Effect of Arsenic on ATP Synthesis
Effect of Arsenic Toxicity on Membrane Integrity
Biochemical and Molecular Effects of Arsenic on Plants
ROS Homeostasis and Plant Development
Impact of Arsenic on Carbohydrate Metabolism in Plants
Arsenic Effect on Lipid Metabolism
Arsenic Effects on Protein Metabolism
Arsenic Impact on Changes in DNA Structure
Detoxification Mechanisms of Arsenic in Plants
Arsenic Complexation and Sequestration in Plants
Role of Antioxidant Enzymes in Arsenic Detoxification in Plants
Role of Proline in Arsenic Detoxification in Plants
Role of Nitric Oxide in Arsenic Detoxification Processes in Plants
Role of Salicylic Acid in Arsenic Detoxification
Findings
10. Conclusions

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.