Responses of nitric oxide and hydrogen sulfide in regulating oxidative defence system in wheat plants grown under cadmium stress

Abstract

We conducted a study to evaluate the interactive effect of NO and H2S on the cadmium (Cd) tolerance of wheat. Cadmium stress considerably reduced total dry weight, chlorophyll a and b content and ratio of Fv/Fm by 36.7, 48.6, 26.7 and 19.5%, respectively, but significantly enhanced the levels of hydrogen peroxide (H2O2) and malondialdehyde (MDA), endogenous H2S and NO, and the activities of antioxidant enzymes. Exogenously applied sodium nitroprusside (SNP) and sodium hydrosulfide (NaHS), donors of NO and H2S, respectively, enhanced total plant dry matter by 47.8 and 39.1%, chlorophyll a by 92.3 and 61.5%, chlorophyll b content by 29.1 and 27.2%, Fv/Fm ratio by 19.7 and 15.2%, respectively, and the activities of antioxidant enzymes, but lowered oxidative stress and proline content in Cd‐stressed wheat plants. NaHS and SNP also considerably limited both the uptake and translocation of Cd, thereby improving the levels of some key mineral nutrients in the plants. Enhanced levels of NO and H2S induced by NaHS were reversed by hypotuarine application, but they were substantially reduced almost to 50% by cPTIO (a NO scavenger) application. Hypotuarine was not effective, but cPTIO was highly effective in reducing the levels of NO and H2S produced by SNP in the roots of Cd‐stressed plants. The results showed that interactive effect of NO and H2S can considerably improve plant resistance against Cd toxicity by reducing oxidative stress and uptake of Cd in plants as well as by enhancing antioxidative defence system and uptake of some essential mineral nutrients.

Exogenous acetylcholine alleviates cadmium-induced phytotoxicity by modulating photosynthetic metabolism and antioxidant potential in tobacco (Nicotiana benthamiana)

“…Photosynthetic attributes are considered as sensitive indicators of abiotic stress, which can be negatively affected by heavy metal toxicity. Reduction in Chl content and gas-exchange parameters was consistent with the finding of Kaya et al (2020), who revealed that Cd-induced a decrease of those indexes in wheat plants exposed to Cd stress. Parmar et al (2013) reported that reduced Chl content in Cd-stressed plants is due to inhibited synthesis of Chl precursor (aminolevulinic acid), which is linked to the reduction of protochlorophyllide to chlorophyllide.…”

Zinc Oxide Nanoparticles Application Alleviates Arsenic (As) Toxicity in Soybean Plants by Restricting the Uptake of as and Modulating Key Biochemical Attributes, Antioxidant Enzymes, Ascorbate-Glutathione Cycle and Glyoxalase System

“…Arsenic stress enhanced the proline accumulation in the soybean plants as has been reported by Choudhury, et al [38] in Oryza sativa and Siddiqui, et al [39] in Withania somnifera. The enhanced accumulation of proline and GB protects biochemical processes, promotes ROS scavenging, and maintains redox homeostasis and functions of different enzymes [40]. According to Hasanuzzaman, et al [41], proline and GB help maintain the plant antioxidant and glyoxalase systems thereby enhancing tolerance against stress.…”

Treatment of nitric oxide supplemented with nitrogen and sulfur regulates photosynthetic performance and stomatal behavior in mustard under salt stress

“…These are the chemical messengers that interrelate with nutrients synergistically or antagonistically and play an imperative role for modulating the physiological responses that lead to salt tolerance (Fatma et al ). Particularly, nitric oxide (NO) has emerged as an ubiquitous important free radical gaseous signaling molecule involved in plant development, various physiological functions and nutrient assimilatory processes and has also been reported to improve plant tolerance to environmental stresses including salt stress, toxic metals, low and high temperature, ultraviolet (UV)‐B, ozone, excess light and various pathogens (Fatma et al , Asgher et al , Per et al , Hasanuzzaman et al , Kaya et al , ). NO plays a pivotal role in alleviating the oxidative damage and improves the antioxidant defense machinery in several salt‐affected plant species (Guo et al , Hasanuzzaman et al , Ahmad et al , , Sehar et al ).…”