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12 pages, 1930 KB

Open AccessArticle

Plant Silicon Defences Suppress Herbivore Growth but Trigger Compensatory Feeding in a Moderate-Accumulating Grass

by Scott N. Johnson, Ximena Cibils-Stewart and Jannatul Ferdous

Plants 2026, 15(9), 1380; https://doi.org/10.3390/plants15091380 - 30 Apr 2026

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Silicon (Si) accumulation is a widespread anti-herbivore defence in grasses, yet little is known about how insects counteract silicification, including via compensatory feeding, or whether Si-mediated changes in plant stoichiometry also influence herbivore performance. We examined how Si supplementation alters foliar Si, carbon [...] Read more.

Silicon (Si) accumulation is a widespread anti-herbivore defence in grasses, yet little is known about how insects counteract silicification, including via compensatory feeding, or whether Si-mediated changes in plant stoichiometry also influence herbivore performance. We examined how Si supplementation alters foliar Si, carbon (C), nitrogen (N), and phosphorus (P) in two grasses with contrasting accumulation strategies, Brachypodium distachyon (high accumulator) and Lolium arundinaceum (moderate accumulator), and the consequences for growth and feeding by Helicoverpa armigera. Plants were grown hydroponically with or without Si, and herbivore relative growth rate (RGR), relative consumption (RC), and Efficiency of Conversion of Ingested food (ECI) were measured. Si supplementation had stronger effects on herbivore performance in B. distachyon compared with L. arundinaceum. RGR declined by 126% on B. distachyon compared with 40% on L. arundinaceum. Herbivores increased RC on Si-supplemented L. arundinaceum, with RC positively correlated with foliar Si concentrations, but no compensatory feeding occurred on B. distachyon. N and P concentrations were positively correlated with RGR in L. arundinaceum and ECI in B. distachyon. In conclusion, the degree of Si accumulation in grasses influences both plant stoichiometry and has contrasting impacts on herbivore feeding strategies. Full article

(This article belongs to the Special Issue Silicon and Its Physiological Role in Plant Growth and Development)

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22 pages, 4360 KB

Open AccessArticle

Silicon Nanoparticles Modulate C:N:P Homeostasis and the Efficiencies of Nutrient Uptake, Translocation, and Use in Sugarcane Under Calcium Deficiency and Sufficiency

by João Victor da Silva Santos, Milton Garcia Costa, João Vitor Silva e Silva, Francisco Sales Ferreira dos Santos, Júnior and Renato de Mello Prado

Plants 2026, 15(6), 971; https://doi.org/10.3390/plants15060971 - 21 Mar 2026

Viewed by 404

Abstract

Calcium (Ca) deficiency is a major nutritional constraint for sugarcane, impairing stoichiometric homeostasis and biomass accumulation. In this context, silicon dioxide nanoparticles (nSiO₂) have emerged as a promising alternative due to their high reactivity and potential to modulate mineral homeostasis. This [...] Read more.

Calcium (Ca) deficiency is a major nutritional constraint for sugarcane, impairing stoichiometric homeostasis and biomass accumulation. In this context, silicon dioxide nanoparticles (nSiO₂) have emerged as a promising alternative due to their high reactivity and potential to modulate mineral homeostasis. This study evaluated the effects of nSiO₂ on C:N:P:Si homeostasis and on nutrient uptake, translocation, and use efficiencies in sugarcane plants grown under Ca deficiency and sufficiency. The experiment was conducted in a greenhouse using a 2 × 2 factorial design, with two Ca conditions (0 and 3 mmol L⁻¹) and two nSiO₂ conditions (0 and 1.77 mmol L⁻¹ of Si), with four replications. Calcium deficiency reduced nutrient accumulation and nutritional efficiencies of several macro- and micronutrients, disrupted stoichiometric ratios, and decreased shoot dry mass. The application of nSiO₂ under Ca deficiency increased Si concentration and accumulation along with other nutrients, reduced C:Si ratios, enhanced nutrient uptake, translocation, and use efficiencies, and resulted in increased shoot biomass. Under Ca-sufficient conditions, nSiO₂ promoted nutritional adjustments and improved nutrient efficiencies but did not affect biomass production. Overall, the results demonstrate that nSiO₂ acts as a nutritional modulator and is more effective in mitigating the adverse effects of Ca deficiency through stoichiometric rebalancing and improved nutrient use efficiencies. Full article

(This article belongs to the Special Issue Silicon and Its Physiological Role in Plant Growth and Development)

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18 pages, 6101 KB

Open AccessArticle

Genotype-Dependent Effects of Silicon on Cell Wall Composition and Antioxidant Responses in Oats Under Nitrogen Deficiency

by Isis Vega, Sofia Pontigo, Patricia Poblete-Grant, Adriano Nunes-Nesi, Paula Cartes and Antonieta Ruiz

Plants 2026, 15(5), 777; https://doi.org/10.3390/plants15050777 - 3 Mar 2026

Viewed by 521

Abstract

Nitrogen (N) availability strongly regulates plant growth and metabolism, and its deficiency constrains plant development and yield. Silicon (Si) has been reported to enhance plant tolerance to multiple stresses; however, its influence on N metabolism in oats remains poorly understood. This study aimed [...] Read more.

Nitrogen (N) availability strongly regulates plant growth and metabolism, and its deficiency constrains plant development and yield. Silicon (Si) has been reported to enhance plant tolerance to multiple stresses; however, its influence on N metabolism in oats remains poorly understood. This study aimed to investigate the effects of Si on cell wall composition and antioxidant responses in oat genotypes grown under N limitation. Two oat genotypes with contrasting N tolerance were hydroponically cultivated under N-deficient (0.5 mM) or N-sufficient (5 mM) conditions in combination with 0 or 2 mM Si. Growth parameters, N and Si uptake, cell wall structural components, phenylalanine ammonia-lyase (PAL) and tyrosine ammonia-lyase (TAL) activities, antioxidant responses, and oxidative damage were evaluated. In both genotypes grown under N deficiency, Si supply reduced shoot N content while enhancing Si accumulation. Moreover, Si application decreased lipid peroxidation in both genotypes under N-deficient conditions. In the N-sensitive genotype, Si increased cellulose deposition and antioxidant activity, whereas in the N-tolerant genotype, Si reduced lignin content and TAL activity. We conclude that Si supplementation improves the metabolic performance of oat genotypes under N-deficient conditions by modulating nutrient uptake, antioxidant responses, and cell wall composition. Full article

(This article belongs to the Special Issue Silicon and Its Physiological Role in Plant Growth and Development)

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22 pages, 4206 KB

Open AccessArticle

Sorbitol-Stabilized Silicon Formulation Improve Root Traits and Antioxidant Response in Drought-Stressed Soybean

by Felipe Sousa Franco, Jonas Pereira de Souza Júnior, Renato de Mello Prado, Milton Garcia Costa, Cid Naudi Silva Campos, Leonardo Motta Berzaghi Junior, Nícolas Leite Capucin, Gustavo Paparotto Lopes, Gabriel Sgarbiero Montanha, Marcia Leticia Monteiro Gomes, Ana Carina da Silva Cândido Seron, Hudson Wallace Pereira de Carvalho, José Lavres and Renan Caldas Umburanas

Plants 2026, 15(2), 197; https://doi.org/10.3390/plants15020197 - 8 Jan 2026

Cited by 1 | Viewed by 708

Abstract

Silicon (Si) plays a critical role in regulating plant physiological processes, particularly through its influence on non-enzymatic antioxidant systems and amino acid metabolism. This study aims to assess soybean performance in response to both soil and foliar Si applications under well-watered and drought [...] Read more.

Silicon (Si) plays a critical role in regulating plant physiological processes, particularly through its influence on non-enzymatic antioxidant systems and amino acid metabolism. This study aims to assess soybean performance in response to both soil and foliar Si applications under well-watered and drought conditions, with the goal of enhancing Si accumulation in plant tissues and potentially strengthening the crop’s physiological responses to water deficit stress. This is especially pertinent given that the mechanisms underlying Si fertilization and its contribution to drought tolerance in soybean remain poorly understood. Greenhouse experiments were conducted using a 3 × 2 factorial design. The factors were: (i) three foliar Si treatments: control (no Si), potassium silicate (SiK; 128 g L⁻¹ Si, 126.5 g L⁻¹ K₂O, pH 12.0), and sorbitol-stabilized potassium silicate (SiKe; 107 g L⁻¹ Si, 28.4 g L⁻¹ K₂O, 100 mL L⁻¹ sorbitol, pH 11.8); and (ii) two soil water levels: well-watered (80% field capacity) and water-restricted (40% field capacity), the latter simulating tropical dry spells. Silicon was applied to the soil via irrigation and to the leaves via foliar spraying prior to the onset water restriction. All Si solutions were adjusted to pH 7.0 with 1 M HCl immediately before application. Potassium (K) levels were standardized across treatments through supplementary applications of KCl to both soil and foliage. Biometric and physiological parameters were subsequently measured. Sorbitol-stabilized Si enhanced Si accumulation in soybean tissues and improved plant resilience under both well-watered and drought conditions by promoting key physiological traits, including increased levels of daidzein and ascorbic acid levels, along with reduced amino acid concentrations. It also improved biometric parameters such as leaf area, root development, and number of pods per plant. These findings further support the role of Si as a beneficial element in enhancing stress tolerance and contributing to sustainable agricultural practices. Full article

(This article belongs to the Special Issue Silicon and Its Physiological Role in Plant Growth and Development)

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17 pages, 3174 KB

Open AccessArticle

Silicon-Mediated Mitigation of Moderate Ammonium Stress in Maize Seedlings

by Hilário Júnior de Almeida, Anelisa de Aquino Vidal Lacerda Soares, Victor Manuel Vergara Carmona and Renato de Mello Prado

Plants 2025, 14(24), 3793; https://doi.org/10.3390/plants14243793 - 12 Dec 2025

Cited by 2 | Viewed by 508

Abstract

Intensive irrigated agriculture relies heavily on nitrogen fertilization, which may cause ammonium accumulation, highly detrimental to sensitive seedlings. Silicon application has emerged as a potential strategy to mitigate this stress, although the underlying mechanisms remain poorly understood. To evaluate this effect, maize seedlings [...] Read more.

Intensive irrigated agriculture relies heavily on nitrogen fertilization, which may cause ammonium accumulation, highly detrimental to sensitive seedlings. Silicon application has emerged as a potential strategy to mitigate this stress, although the underlying mechanisms remain poorly understood. To evaluate this effect, maize seedlings were grown in nutrient solution under five N concentrations (1.4, 3.6, 7.1, 14.3, and 28.6 mmol L⁻¹), applied in the presence or absence of silicon (1.8 mmol L⁻¹ Si). The nitrogen source was a mixture of nitrate and ammonium in a N-NO₃⁻: N-NH₄⁺ ratio of 4:5. Silicon was supplied as monosilicic acid (H₂SiO₃). Plant growth, leaf area, root morphology (length, diameter, density), N and Si accumulation, uptake and utilization efficiency, SPAD index, nitrate reductase activity, and proline content were evaluated. Silicon supplementation enhanced nitrate reductase activity, SPAD values, leaf area, and root traits, reduced proline in roots and shoots, and improved N uptake and partitioning. Among the tested N concentrations, 14.3 mmol L⁻¹ achieved the highest efficiency of nutrient absorption and biomass production, highlighting silicon as a sustainable strategy to mitigate ammonium stress in maize seedlings. Full article

(This article belongs to the Special Issue Silicon and Its Physiological Role in Plant Growth and Development)

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23 pages, 2287 KB

Open AccessArticle

Silicon as a Strategy to Mitigate Abiotic Stresses and Improve Physiological Performance and Grain Yield of Maize Grown Under Tropical Climate Conditions

by Mateus de Leles Lima, Rilner Alves Flores, Maxuel Fellipe Nunes Xavier, Renato Gomide de Sousa, Derblai Casaroli, Felipe Puff Dapper, Frank Freire Capuchinho, Glenio Guimarães Santos, Klaus de Oliveira Abdala and Letusa Momesso

Plants 2025, 14(17), 2755; https://doi.org/10.3390/plants14172755 - 3 Sep 2025

Cited by 2 | Viewed by 1663

Abstract

Although the beneficial effects of silicon on plant resistance to biotic and abiotic stresses are recognized, there is a lack of knowledge regarding its application in field conditions and its direct impact on physiological metabolism, root development, and, most importantly, the economic return [...] Read more.

Although the beneficial effects of silicon on plant resistance to biotic and abiotic stresses are recognized, there is a lack of knowledge regarding its application in field conditions and its direct impact on physiological metabolism, root development, and, most importantly, the economic return of corn production in tropical regions. This study is justified by the need to quantify the effects of foliar silicon application on these variables, providing a scientific and economic basis for optimizing corn productivity and profitability in tropical environments. The objective of this study was to evaluate the effect of silicon on physiological metabolism, root system development, grain yield, and the potential economic return of maize production in a tropical region. The study was conducted under field conditions in two growing seasons (2020 and 2021), using a randomized block design in a 2 × 5 factorial arrangement with four replications. The first factor consisted of the maize growing seasons, and the second factor was foliar silicon fertilization (0 (control), 150, 300, 450, and 600 g ha⁻¹). Foliar fertilization with silicon at a dose of 150 g ha⁻¹ increases transpiration rate by up to 9%, net photosynthetic rate by 13%, and grain yield of maize by 10% after two growing seasons, regardless of the water deficit experienced during the crop cycle. At this dose, silicon application is economically viable, yielding the highest differential profit (USD 97.11 ha⁻¹). In conclusion, foliar fertilization with silicon is an agronomically and economically viable strategy for efficient maize grain production during the second growing season in tropical regions. Full article

(This article belongs to the Special Issue Silicon and Its Physiological Role in Plant Growth and Development)

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18 pages, 8048 KB

Open AccessArticle

Silicon Nanoparticles Alter Soybean Physiology and Improve Nitrogen Fixation Potential Under Atmospheric Carbon Dioxide (CO₂)

by Jingbo Tong

Plants 2025, 14(13), 2009; https://doi.org/10.3390/plants14132009 - 30 Jun 2025

Cited by 3 | Viewed by 1529

Abstract

The interactive effects between nano-silicon dioxide (n-SiO₂) and elevated CO₂ (eCO₂; 645 ppm) on soybean physiology, nitrogen fixation, and nutrient dynamics under climate stress remain underexplored. This study elucidates their combined effects under ambient (aCO₂ [...] Read more.

The interactive effects between nano-silicon dioxide (n-SiO₂) and elevated CO₂ (eCO₂; 645 ppm) on soybean physiology, nitrogen fixation, and nutrient dynamics under climate stress remain underexplored. This study elucidates their combined effects under ambient (aCO₂; 410 ppm) and eCO₂ conditions. eCO₂ + n-SiO₂ synergistically enhanced shoot length (30%), total chlorophyll (112.15%), and photosynthetic rate (103.23%), alongside improved stomatal conductance and intercellular CO₂ (17.19%), optimizing carbon assimilation. Nodulation efficiency increased, with nodule number and biomass rising by 48.3% and 53.6%, respectively, under eCO₂ + n-SiO₂ versus aCO₂. N-assimilation enzymes (nitrate reductase, nitrite reductase, glutamine synthetase, glutamate synthase) surged by 38.5–52.1%, enhancing nitrogen metabolism. Concurrently, phytohormones (16–21%) and antioxidant activities (15–22%) increased, reducing oxidative markers (18–22%), and bolstering stress resilience. Nutrient homeostasis improved, with P, K, Mg, Cu, Fe, Zn, and Mn elevating in roots (13–41%) and shoots (13–17%), except shoot Fe and Zn. These findings demonstrate that n-SiO₂ potentiates eCO₂-driven benefits, amplifying photosynthetic efficiency, nitrogen fixation, and stress adaptation through enhanced biochemical and nutrient regulation. This synergy underscores n-SiO₂ role in optimizing crop performance under future CO₂-rich climates, advocating nano-fertilizers as sustainable tools for climate-resilient agriculture. Full article

(This article belongs to the Special Issue Silicon and Its Physiological Role in Plant Growth and Development)

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15 pages, 1742 KB

Open AccessArticle

Silicon Reduce Structural Carbon Components and Its Potential to Regulate the Physiological Traits of Plants

by Baiying Huang, Danghui Xu, Wenhong Zhou, Yuqi Wu and Wei Mou

Plants 2025, 14(12), 1779; https://doi.org/10.3390/plants14121779 - 11 Jun 2025

Cited by 5 | Viewed by 1289

Abstract

Phosphorus (P) and silicon (Si) could profoundly affect the net primary productivity (ANPP) of grassland ecosystems. However, how ecosystem biomass will respond to different Si addition, especially under a concurrent increase in P fertilization, remains limited. With persistent demand for grassland utilization, there [...] Read more.

Phosphorus (P) and silicon (Si) could profoundly affect the net primary productivity (ANPP) of grassland ecosystems. However, how ecosystem biomass will respond to different Si addition, especially under a concurrent increase in P fertilization, remains limited. With persistent demand for grassland utilization, there is a need to enhance and sustain the productivity of grasslands on the Qinghai–Tibet Plateau. Three P addition rates (0, 400, 800, and 1200 kg Ca(H₂PO₄)₂ ha⁻¹ yr⁻¹) without Si and with Si (14.36 kg H₄SiO₄ ha⁻¹ yr⁻¹) were applied to alpine grassland on the Qinghai–Tibet Plateau to evaluate the responses of aboveground biomass and the underlying mechanisms linking to structural carbon composition and physiological traits of grasses and forbs. Our results show that the application of Si significantly reduced the lignin, cellulose, hemicellulose, and total phenol contents of both grasses and forbs. Additionally, the addition of P, Si, and phosphorus and silicon (PSi) co-application significantly increased the net photosynthetic rate (Pn) and light use efficiency (LUE) of grasses and forbs. Moreover, Si promoted the absorption of N and P by plants, resulting in significant changes in the Si:C, Si:P, and Si:N ratios and increasing the aboveground biomass. Our findings suggest that Si can replace structural carbohydrates and regulate the absorption and utilization of N and P to optimize the photosynthetic process of leaves, thereby achieving greater biomass. In summary, Si supplementation improves ecosystem stability in alpine meadows by optimizing plant functions and increasing biomass accumulation. Full article

(This article belongs to the Special Issue Silicon and Its Physiological Role in Plant Growth and Development)

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