Response of glutathione pools to cadmium stress and the strategy to translocate cadmium from roots to leaves (Daucus carota L.)

Ya Gao; Haipu Li; Yang Song; Fenglin Zhang; Zhaoguang Yang; Ying Yang; Teresa Grohmann

doi:10.1016/j.scitotenv.2022.153575

Response of glutathione pools to cadmium stress and the strategy to translocate cadmium from roots to leaves (Daucus carota L.)

Sci Total Environ. 2022 Jun 1:823:153575. doi: 10.1016/j.scitotenv.2022.153575. Epub 2022 Jan 31.

Authors

Ya Gao¹, Haipu Li², Yang Song¹, Fenglin Zhang¹, Zhaoguang Yang³, Ying Yang⁴, Teresa Grohmann⁵

Affiliations

¹ Center for Environment and Water Resources, College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, PR China; Key Laboratory of Hunan Province for Water Environment and Agriculture Product Safety, Central South University, Changsha 410083, PR China.
² Center for Environment and Water Resources, College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, PR China; Key Laboratory of Hunan Province for Water Environment and Agriculture Product Safety, Central South University, Changsha 410083, PR China. Electronic address: lihaipu@csu.edu.cn.
³ Center for Environment and Water Resources, College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, PR China; Key Laboratory of Hunan Province for Water Environment and Agriculture Product Safety, Central South University, Changsha 410083, PR China. Electronic address: zgyang3@gmail.com.
⁴ Center for Environment and Water Resources, College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, PR China.
⁵ School of Agriculture and Food Science, University College Dublin, Belfield, Dublin 4, Ireland.

PMID: 35114244
DOI: 10.1016/j.scitotenv.2022.153575

Abstract

Carrots are one of the most highly consumed vegetables in the world. Due to the large area of cadmium (Cd) contaminated farmland, to abate the impact of Cd contamination on carrot quality and safety, a novel strategy is required to drive Cd translocation from the soil to the overground leafy tissues of carrots to protect the edible roots and thus ensure food security. To this end, this article presents an experimental study with mathematical models to assess the tolerance and accumulation capacity of Cd in inedible carrot leaves, as well as the regulatory factors affecting Cd distribution in carrots. The glutathione (GSH) pools were examined in carrot leaves in response to the oxidation stress induced by Cd exposures, and it was found that under low Cd stress (1 and 3 mg/L) the changes of GSH pools were dominated by the variation of GSH, showing higher GSH content and low levels of oxidized GSH content (GSSG). In contrast, both of these two indicator variables as well as the GSH/GSSG ratio all decreased under high Cd stress (5 and 9 mg/L). Combining this information with Cd concentrations in leaves, a model was established to predict the Cd accumulation capacity of leaves. The data showed that the potential Cd accumulation in carrot leaves could be as high as 514 μg/kg dry weight. Furthermore, the factors and primary physiological indicators affecting and regulating GSH pools by multiple stepwise regression were analyzed. The results showed that increasing chlorophyll a/b ratio and γ-glutamylcyclotransferase activity while inhibiting phytochelatin synthase activity could expand the tolerance of carrot leaves to Cd. These findings suggest a possible strategy for regulating the distribution of toxic metals in plants through a molecular-based approach and provide some important information that could be conducive to achieving food safety and phytoremediation of contaminated soils.

Keywords: Cadmium; Carrot leaf; Changes of enzyme activity; Contaminated soil; Glutathione pool.

MeSH terms

Cadmium / analysis
Chlorophyll A
Daucus carota*
Glutathione
Plant Leaves / chemistry
Plant Roots / chemistry
Soil Pollutants* / analysis
Soil Pollutants* / toxicity

Substances

Soil Pollutants
Cadmium
Glutathione
Chlorophyll A