Contribution of glutathione to the control of cellular redox homeostasis under toxic metal and metalloid stress.
The accumulation of toxic metals and metalloids, such as cadmium (Cd), mercury (Hg), or arsenic (As), as a consequence of various anthropogenic activities, poses a serious threat to the environment and human health. The ability of plants to take up mineral nutrients from the soil can be exploited to develop phytoremediation technologies able to alleviate the negative impact of toxic elements in terrestrial ecosystems. However, we must select plant species or populations capable of tolerating exposure to hazardous elements. The tolerance of plant cells to toxic elements is highly dependent on glutathione (GSH) metabolism. GSH is a biothiol tripeptide that plays a fundamental dual role: first, as an antioxidant to mitigate the redox imbalance caused by toxic metal(loid) accumulation, and second as a precursor of phytochelatins (PCs), ligand peptides that limit the free ion cellular concentration of those pollutants. The sulphur assimilation pathway, synthesis of GSH, and production of PCs are tightly regulated in order to alleviate the phytotoxicity of different hazardous elements, which might induce specific stress signatures. This review provides an update on mechanisms of tolerance that depend on biothiols in plant cells exposed to toxic elements, with a particular emphasis on the Hg-triggered responses, and considering the contribution of hormones to their regulation.
Laboratory of Plant Physiology, Department of Biology, Universidad Autónoma de Madrid, Cantoblanco, ES-28049 Madrid, Spain luise.hernandez@uam.es.
Luis E
http://orcid.org/0000-0003-3492-5813
LE
Hernández
Laboratory of Plant Physiology, Department of Biology, Universidad Autónoma de Madrid, Cantoblanco, ES-28049 Madrid, Spain Department of Environmental Sciences, Universidad de Castilla-La Mancha, Campus Fábrica de Armas, ES-45070 Toledo, Spain.
Juan
J
Sobrino-Plata
Laboratory of Plant Physiology, Department of Biology, Universidad Autónoma de Madrid, Cantoblanco, ES-28049 Madrid, Spain Department of Environmental Sciences, Universidad de Castilla-La Mancha, Campus Fábrica de Armas, ES-45070 Toledo, Spain.
M Belén
MB
Montero-Palmero
Laboratory of Plant Physiology, Department of Biology, Universidad Autónoma de Madrid, Cantoblanco, ES-28049 Madrid, Spain † Present address: Aula Dei Experimental Research Station-CSIC, Avd. Montañana, ES- 50059 Zaragoza, Spain.
Sandra
S
Carrasco-Gil
Laboratory of Plant Physiology, Department of Biology, Universidad Autónoma de Madrid, Cantoblanco, ES-28049 Madrid, Spain.
M Laura
ML
Flores-Cáceres
Laboratory of Plant Physiology, Department of Biology, Universidad Autónoma de Madrid, Cantoblanco, ES-28049 Madrid, Spain.
Cristina
C
Ortega-Villasante
Department of Environmental Sciences, Universidad de Castilla-La Mancha, Campus Fábrica de Armas, ES-45070 Toledo, Spain.
Carolina
C
Escobar
D005978:Glutathione / Q000378:metabolism*; D006706:Homeostasis; D008628:Mercury / Q000633:toxicity; D058955:Metalloids / Q000633:toxicity*; D008670:Metals / Q000633:toxicity*; D010084:Oxidation-Reduction; D010937:Plant Growth Regulators / Q000378:metabolism*; D018521:Plant Physiological Phenomena / Q000187:drug effects*; D013438:Sulfhydryl Compounds / Q000378:metabolism*
D058955:Metalloids; D008670:Metals; D010937:Plant Growth Regulators; D013438:Sulfhydryl Compounds; D008628:Mercury; D005978:Glutathione
Detoxification; glutathione; hormones; metal(loid)s; phytochelatins; phytotoxicity; redox homeostasis; sulphur.