Effect of nano-silicon on the regulation of ascorbate-glutathione contents, antioxidant defense system and growth of copper stressed wheat (Triticum aestivum L.) seedlings

Muhammad Riaz; Shaopeng Zhao; Muhammad Kamran; Naveed Ur Rehman; Freddy Mora-Poblete; Carlos Maldonado; Muhammad Hamzah Saleem; Aasma Parveen; Abdullah Ahmed Al-Ghamdi; Fahad M Al-Hemaid; Shafaqat Ali; Mohamed S Elshikh

doi:10.3389/fpls.2022.986991

Effect of nano-silicon on the regulation of ascorbate-glutathione contents, antioxidant defense system and growth of copper stressed wheat (Triticum aestivum L.) seedlings

Front Plant Sci. 2022 Oct 13:13:986991. doi: 10.3389/fpls.2022.986991. eCollection 2022.

Authors

Affiliations

¹ College of Resources and Environment, Zhongkai University of Agriculture and Engineering, Guangzhou, China.
² College of Natural Resources and Environment, South China Agricultural University, Guangzhou, China.
³ School of Agriculture, Food and Wine, The University of Adelaide, Adelaide, SA, Australia.
⁴ Provincial Key Laboratory of Plant Molecular Breeding, South China Agricultural University, Guangzhou, China.
⁵ Institute of Biological Sciences, University of Talca, Talca, Chile.
⁶ Centro de Genómica y Bioinformática, Facultad de Ciencias, Universidad Mayor, Santiago, Chile.
⁷ College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China.
⁸ Department of Soil Science, Faculty of Agriculture and Environmental Sciences, The Islamia University of Bahawalpur, Bahawalpur, Pakistan.
⁹ Department of Botany and Microbiology, College of Science, King Saud University, Riyadh, Saudi Arabia.
¹⁰ Department of Environmental Sciences and Engineering, Government College University, Faisalabad, Pakistan.
¹¹ Department of Biological Sciences and Technology, China Medical University, Taichung, Taiwan.

Abstract

Copper (Cu²⁺) toxicity can inhibit plant growth and development. It has been shown that silicon (Si) can relieve Cu²⁺ stress. However, it is unclear how Si-nanoparticles (SiNPs) relieve Cu²⁺ stress in wheat seedlings. Therefore, the current study was conducted by setting up four treatments: CK, SiNP: (2.5 mM), Cu²⁺: (500 µM), and SiNP+Cu²⁺: (2.5 mM SiNP+500 µM Cu²⁺) to explore whether SiNPs can alleviate Cu²⁺ toxicity in wheat seedlings. The results showed that Cu²⁺ stress hampered root and shoot growth and accumulated high Cu²⁺ concentrations in roots (45.35 mg/kg) and shoots (25.70 mg/kg) of wheat as compared to control treatment. Moreover, Cu²⁺ treatment inhibited photosynthetic traits and chlorophyll contents as well as disturbed the antioxidant defense system by accumulating malondialdehyde (MDA) and hydrogen peroxidase (H₂O₂) contents. However, SiNPs treatment increased root length and shoot height by 15.1% and 22%, respectively, under Cu²⁺ toxicity. Moreover, SiNPs application decreased MDA and H₂O₂ contents by 31.25% and 19.25%, respectively. SiNPs increased non-enzymatic compounds such as ascorbic acid-glutathione (AsA-GSH) and enhanced superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbic peroxidase (APX) activities by 77.5%, 141.7%, 68%, and 80%, respectively. Furthermore, SiNPs decreased Cu²⁺ concentrations in shoots by 26.2%, as compared to Cu²⁺ treatment alone. The results concluded that SiNPs could alleviate Cu²⁺ stress in wheat seedlings. The present investigation may help to increase wheat production in Cu²⁺ contaminated soils.

Keywords: AsA-GSH; copper toxicity; oxidative stress; silicon; wheat.