Role of Exogenous and Endogenous Hydrogen Sulfide (H2S) on Functional Traits of Plants Under Heavy Metal Stresses: A Recent Perspective

Abstract

Improving growth and productivity of plants that are vulnerable to environmental stresses, such as heavy metals, is of significant importance for meeting global food and energy demands. Because heavy metal toxicity not only causes impaired plant growth, it has also posed many concerns related to human well-being, so mitigation of heavy metal pollution is a necessary priority for a cleaner environment and healthier world. Hydrogen sulfide (H2S), a gaseous signaling molecule, is involved in metal-related oxidative stress mitigation and increased stress tolerance in plants. It performs multifunctional roles in plant growth regulation while reducing the adverse effects of abiotic stress. Most effective function of H2S in plants is to eliminate metal-related oxidative toxicity by regulating several key physiobiochemical processes. Soil pollution by heavy metals presents significant environmental challenge due to the absence of vegetation cover and the resulting depletion of key soil functions. However, the use of stress alleviators, such as H2S, along with suitable crop plants, has considerable potential for an effective management of these contaminated soils. Overall, the present review examines the imperative role of exogenous application of different H2S donors in reducing HMs toxicity, by promoting plant growth, stabilizing their physiobiochemical processes, and upregulating antioxidative metabolic activities. In addition, crosstalk of different growth regulators with endogenous H2S and their contribution to the mitigation of metal phytotoxicity have also been explored.

Biochar supplementation regulates growth and heavy metal accumulation in tomato grown in contaminated soils

“…The same findings were also documented by Opeolu et al (2010), they also demonstrated that the number of branches per tomato plant was reduced with increased heavy metal contamination of the soil. It has been suggested that reduction in plant growth and biomass may be due to heavy metal accumulation in the plant system, which disturbs biochemical and physiological activities and eventually leads to a reduction in growth and yield (Arif et al, 2021; Singh & Agarwal, 2010).…”

Hydrogen sulfide: an emerging component against abiotic stress in plants

“…The oxidative damage caused by heavy metals can be counteracted by maintaining redox homeostasis and levels of antioxidant enzymes (Gautam et al 2020;Raza et al 2021b). H 2 S, as a vital gaseous molecule, interacts with other molecules to reduce abiotic stresses, including heavy metal stress (Arif et al 2020;Huang et al 2021;Liu & Xue 2021). The tolerance to abiotic stresses, such as heavy metals in plants, can be boosted by H 2 S addition, regulating the transport of metal ions (Huang et al 2021;Liu & Xue, 2021).…”

Hydrogen sulphide and salicylic acid regulate antioxidant pathway and nutrient balance in mustard plants under cadmium stress

“…hydrogen sulphide (H 2 S) and plant growth regulators (PGR) like salicylic acid (SA), to Cd stressed plants has received attention from researchers worldwide (Wang et al 2019;Luo et al 2020). To cope up with heavy metals, sulphur-induced defence mechanisms are among the most important strategies adopted by plants (Keyster et al 2020;Arif et al 2021). Hydrogen sulphide (H 2 S), a sulphurcontaining compound, has manifold functions in regulating key plant metabolic processes, e.g.…”

“…2020; Arif et al . 2021). Hydrogen sulphide (H 2 S), a sulphur‐containing compound, has manifold functions in regulating key plant metabolic processes, e.g .…”