Alleviatory effects of Silicon on the morphology, physiology, and antioxidative mechanisms of wheat (Triticum aestivum L.) roots under cadmium stress in acidic nutrient solutions

Abstract

Silicon (Si), as a quasi-essential element, has a vital role in alleviating the damaging effects of various environmental stresses on plants. Cadmium (Cd) stress is severe abiotic stress, especially in acidic ecological conditions, and Si can demolish the toxicity induced by Cd as well as acidic pH on plants. Based on these hypotheses, we demonstrated 2-repeated experiments to unfold the effects of Si as silica gel on the root morphology and physiology of wheat seedling under Cd as well as acidic stresses. For this purpose, we used nine treatments with three levels of Si nanoparticles (0, 1, and 3 mmol L−1) derived from sodium silicate (Na2SiO3) against three concentrations of Cd (0, 50, and 200 µmol L−1) in the form of cadmium chloride (CdCl2) with three replications were arranged in a complete randomized design. The pH of the nutrient solution was adjusted at 5. The averages of three random replications showed that the mutual impacts of Si and Cd in acidic pH on wheat roots depend on the concentrations of Si and Cd. The collective or particular influence of low or high levels of Si (1 or 3 mM) and acidic pH (5) improved the development of wheat roots, and the collective influence was more significant than that of a single parallel treatment. The combined effects of low or high concentrations of Cd (50 or 200 µM) and acidic pH significantly reduced root growth and biomass while increased antioxidants, and reactive oxygen species (ROS) contents. The incorporation of Si (1 or 3 mmol L−1) in Cd-contaminated acidic nutrient solution promoted the wheat root growth, decreased ROS contents, and further increased the antioxidants in the wheat roots compared with Cd single treatments in acidic pH. The demolishing effects were better with a high level of Si (3 mM) than the low level of Si (1 Mm). In conclusion, we could suggest Si as an effective beneficial nutrient that could participate actively in several morphological and physiological activities of roots in wheat plants grown under Cd and acidic pH stresses.

The interactive effect of pH variation and cadmium stress on wheat (Triticum aestivum L.) growth, physiological and biochemical parameters

“…The root and shoot samples were digested by adding nitric acid at the rate of 10 mL in each tube and covered the samples with a lid. After that, the digestion process was started using a microwave digestion instrument with appropriate programming, as mentioned by Ur Rahman [2]. The digested samples were removed from the microwave digestion instrument and put into the PTFE digestion cup.…”

“…Among heavy metals, cadmium (Cd) is declared as hazardous to the environment by the Agency for Toxic Substances and Disease Registry (ATSDR) [1]. It might be due to its high mobility, leaching capacity, and ability to contaminate aquifers [2]. Plants grown in polluted soil actively absorb and accumulate Cd in different plant parts, resulting in plant toxicity, growth abnormalities, reduce yield, and adverse effects even at low concentrations [3].…”

Iron Oxide and Silicon Nanoparticles Modulate Mineral Nutrient Homeostasis and Metabolism in Cadmium-Stressed Phaseolus vulgaris

“…In the present study, IONPs and SiNPs treatment increased LRWC in P. vulgaris seedling ( Table 1 ). Before, it was also reported that SiNP treatment enhanced gas exchange characteristics in plants exposed to Cd-contaminated media ( Ur Rahman et al, 2021 ). Cadmium stress destabilized photosynthetic apparatus, yet IONPs and SiNPs application reduced injury to photosynthetic machinery.…”

Effect of Organic Amendments in Soil on Physiological and Biochemical Attributes of Vachellia nilotica and Dalbergia sissoo under Saline Stress

“…The mixture was passed through the process of centrifugation at 12,000× g resolution for a period of 20 min. The detailed procedure for determining the activities of SOD and POD is described earlier in [96,97], while CAT activity was determined according to the procedure described earlier in [98].…”