Involvement of glutathione and glutathione metabolizing enzymes in Pistia stratiotes tolerance to arsenite

• Published in: International journal of phytoremediation Vol. 22; no. 4; pp. 404 - 411
• Main Authors: Campos, Fernanda Vidal de, Oliveira, Juraci Alves de, Silva, Adinan Alves da, Ribeiro, Cleberson, Montoya, Sebastián Giraldo, Farnese, Fernanda dos Santos
• Format: Journal Article
• Language: English
• Published: United States Taylor & Francis 20.03.2020; Taylor & Francis Ltd
• Subjects: Araceae; Arsenic; Arsenite; Arsenites; Biodegradation, Environmental; Cell membranes; Coordination; Cysteine; Enzymatic activity; Enzymes; Glutathione; glutathione metabolism; Glutathione peroxidase; Glutathione reductase; Glutathione transferase; Homeostasis; Integrity; macrophytes; Membranes; Metabolism; Oxidation; Peroxidase; phytoremediation; Pistia stratiotes; Reductases; Toxicity; water contamination; macrophytes; glutathione metabolism; water contamination; phytoremediation; Arsenic
• ISSN: 1522-6514; 1549-7879
• DOI: 10.1080/15226514.2019.1667951

Glutathione is essential for plant tolerance to arsenic but few studies have focused on the coordination between the enzymes involved in its metabolism. We exposed Pistia stratiotes to four treatments (control, 5, 10 and 20 µM As III ) for 24 h to evaluate the role of glutathione metabolism in arsenic response and determined the arsenic uptake, growth, membrane integrity, glutathione concentration and enzyme activities (γ-glutamyl-cysteine synthetase, glutathione reductase, glutathione peroxidase, and glutathione-S-transferase). Despite absorbing high concentrations of As III , plants maintained growth and cell membrane integrity when exposed to concentrations of up to 10 µM As III . The maintenance of these parameters involved glutathione concentration increase due to an increase in its biosynthetic pathway (higher γ-glutamyl-cysteine synthetase). In addition, an increase in the activity of glutathione reductase, glutathione peroxidase and glutathione-S-transferase also contributed to the conserve the cellular homeostasis. However, at the concentration of 20 µM As III , the high toxicity of As III affected glutathione concentration and glutathione metabolizing enzymes activities, which resulted in drastic decrease in growth and damage to cell membranes. These results showed that not only the glutathione concentration but also the coordination of the enzymes involved in the synthesis, oxidation and reduction pathways of glutathione is essential for As III tolerance.