Effect of silicon on morpho-physiological attributes, yield and cadmium accumulation in two maize genotypes with contrasting root system size and health risk assessment

Abstract

Background and aims Cadmium (Cd) contamination is a serious threat to plants and humans. Silicon (Si) was reported to have some alleviative effects on Cd stress in plants. However, whether Si alleviates Cd toxicity in maize genotypes with contrasting root system size are unknown. Methods Effects of Si application (200 mg kg−1 soil) on shoot and root growth, Cd uptake and transportation under Cd stress (20 mg kg−1 soil) were assessed at the silking and maturity stages of maize genotypes Zhongke11 (deep-rooted) and Shengrui999 (shallow-rooted) in a pot experiment. Results Application of Si significantly increased root dry weight, plant height and root length. Root volume and average root diameter were significantly positively correlated with root Cd concentration, bioaccumulation and translocation factor, respectively, of two maize genotypes at the silking stage. Addition of Si significantly increased Cd concentration, content, bioconcentration and translocation factor in roots of Zhongke11, but reduced the values of these parameters in Shengrui9999 at both growth stages. Grain Cd concentration in the combined Cd and Si treatment was decreased by 14.4% (Zhongke11) and 21.4% (Shengrui999) than that in Cd treatment. Grain yield was significantly negatively correlated with root Cd accumulation. Moreover, addition of Si significantly reduced Cd daily intake and health risk index in maize. Conclusions This study demonstrated that addition of Si reduced health risk by eliminating Cd accumulation in maize shoot and grain, and alleviated Cd stress with more profound effects in the shallow-rooted genotype Shengrui999.

Silicon-mediated improvement of biomass yield and physio-biochemical attributes in heat-stressed spinach (

“…Both types of injury or death can lead to the shedding or shortening of leaves, reduction in fresh and dry biomass, or even death of the entire plant (Abdelrahman et al 2017;Das et al 2017;Fahad et al 2017;Hussain et al 2019). The results presented here concur with those of previous reports by Mahdieh et al (2015), Abbas et al (2017), andAn et al (2022), where the application of exogenous Si alleviated the negative effects of abiotic stress and restored plant growth. In the present investigation, we found improved leaf area, better growth, and greater fresh and dry weights in response to application of Si (Fig.…”

“…This suggests the involvement of Si in cell division and expansion, which might lead to internodal elongation and influence the height of the plant (Soundararajan et al 2014;Hussain et al 2019;Younis et al 2020). The literature reveals that Si is considered a plant-growth-regulator-like compound that is necessary for cell division and expansion (Hwang et al 2007;Khan et al 2020a;An et al 2022), and has a defensive role against a wide range of environmental stresses (Tripathi et al 2013;Shalaby et al 2021). In all green plants, the most fundamental physiological process is photosynthesis, and all of its components are sensitive to stress conditions; any type of stress at any stage of life affects overall photosynthetic efficiency of green plants (Alabdallah et al 2021).…”

Alleviation of Cadmium Stress by Silicon Supplementation in Peas by the Modulation of Morpho-Physio-Biochemical Variables and Health Risk Assessment

“…These findings indicate that Si treatment using various Si salts under Cd stress showed a significant reduction in Cd 2+ to its optimum concentration in various plant tissues of peas. This demonstrates that Si restricted the uptake of Cd 2+ by pea roots and limited movement into plant leaves [ 61 ]. Likewise, similar outcomes were also accounted for in alfalfa [ 56 ], maize ( Zea mays ) [ 61 ], wheat [ 2 ] and rice [ 1 ].…”

“…This demonstrates that Si restricted the uptake of Cd 2+ by pea roots and limited movement into plant leaves [ 61 ]. Likewise, similar outcomes were also accounted for in alfalfa [ 56 ], maize ( Zea mays ) [ 61 ], wheat [ 2 ] and rice [ 1 ]. The rise in plant resistance to Cd 2+ might be due to a decline in Cd 2+ uptake and transport and to advances in plant resilience [ 62 ].…”

Abscisic acid: Metabolism, transport, crosstalk with other plant growth regulators, and its role in heavy metal stress mitigation

“…In another Brassica juncea L. study, Cr, Pb, Cd, and Hg application at 100, 200, 10, and 50 mg kg –1 soil, respectively, decreased root and stem dry weights ( Sheetal et al, 2016 ). Two Zea mays L. genotypes with contrasting root systems exhibited differential growth responses to moderate Cd stress (20 mg kg –1 soil) with less growth reduction in small-rooted genotypes than large-rooted genotypes ( An et al, 2022a , b ).…”