Open research questions in Silicon Effects in Agriculture

What the literature leaves open

• This study demonstrates that Si fertilization substantially enhances soybean performance under both non-saline and saline conditions by improving plant physiology, biomass production, and soil carbon processes. Across the 30 soybean genotypes, Si application increased shoot length by 7.3%, root length by 20.8%, shoot dry biomass by 39.2%, root dry biomass by 52.8%, total dry biomass by 45.4%, and net CO₂ assimilation by 27.8% under non- saline conditions compared with the untreated control. Under salinity stress, Si application increased shoot length by 2.1%, root length by 21.9%, shoot dry biomass by 43.6%, root dry biomass by 50.5%, total dry biomass by 46.7%, and net CO₂ assimilation by 30.5% compared with salinity alone. Si often restored growth under salinity stress to levels comparable to the non- stressed control. Si amendments also elevated root Si content, soil organic carbon, soil carbonic anhydrase activity, and rhizospheric CO₂ dynamics, indicating tighter coupling between above- and below-ground carbon fluxes in Si-treated systems. Responses were strongly genotype-dependent. Lee S- 100, Biloxi, Lee68, Clemson, and Cherokee consistently combined higher Si uptake with gains in biomass, photosynthesis, and soil-C metrics, identi- fying them as top Si-responsive, salinity-tolerant candidates. Random Forest reinforced this pattern by ranking Si treatments as dominant drivers and prioritizing genotypes with the greatest Si-mediated mitigation, stability, and rhizospheric CO₂ flux potential. Overall, the G×Si×S interactions were predominantly positive (synergistic), where Si generally buffered salinity by restoring above- and below-ground growth performance toward control levels. The magnitude of benefit varied by genotype and was limited in some backgrounds. This study was conducted under controlled greenhouse conditions, which allowed precise evaluation of the G×Si×S interactions. However, greenhouse conditions may not fully represent field variability in soil type, drainage, microbial communities, and fluctuating salinity. Future work should validate these greenhouse findings under field conditions across contrasting soil types and salinity gradients, using the most promising genotypes (e.g., Lee S-100, Biloxi, Lee68, Clemson, and Cherokee) to quantify Si-mediated gains in yield, grain quality, and long-term soil carbon storage. Multi-omics approaches (transcriptomics and metabolomics) combined with targeted analysis of Si transporters and salinity-tolerant genes will be critical for unraveling the molecular networks that underlie differential Si uptake, stress mitigation, and CO₂ sequestration among genotypes. Integrating these data with hyperspectral sensing, detailed soil biogeochemistry (including reactive nutrient-Si weathering interactions), and advanced machine-learning models will enable predictive frameworks that rank genotypes and management regimes for both productivity and climate benefits. These findings support genotype-specific nutrient supplementation strategies for maintaining sustainable crop productivity and carbon management in saline ecosystems.

  Silicate-genotype interactions help improve stress tolerance of Glycine max and CO2 dynamics in saline soil · 2026 · DOI

• As a globally important vegetable crop, cucumber fruit is favored for its unique taste and nutritional value. However, with increasing global climate change and extreme low- temperature events, cucumber has been exposed to low-temperature stress during growth, severely affecting yield and quality. In response to this adversity, cucumber has developed a variety of adaptive mechanisms, including morphological, physiological, biochemical, genetic, and proteomic strategies, to enhance cold resistance. Recent advances in the understanding of plant responses to low-temperature stress —particularly discoveries related to transcription factors, signaling pathways, and regula- tory networks—have provided crucial insights into the molecular mechanisms governing cucumber’s cold tolerance. Nevertheless, compared to model plants like Arabidopsis or major crops like rice, many aspects of cucumber’s molecular regulatory networks and physiological mechanisms under low-temperature stress remain insufficiently explored. Key areas requiring further investigation include the dynamic changes in endogenous hormones, mechanisms of osmoregulatory substance accumulation, and roles of critical signaling molecules. Rapid developments in high-throughput sequencing, gene editing (e.g., CRISPR/Cas9), and multi-omics integration are poised to drive breakthroughs in identifying and char- acterizing cold-tolerance genes. These technologies will elucidate the molecular founda- tions of cucumber low-temperature responses and support the development of innovative cold-resistant germplasm and breeding strategies. Integrating genomics, transcriptomics, proteomics, and metabolomics will comprehensively reveal regulatory networks under low-temperature stress, laying a foundation for breeding high-yield, high-quality, and stress-resistant cucumber varieties. The effects of low-temperature stress on agriculture are widespread. Beyond cucumber, numerous other vital economic crops, such as pepper and citrus (Citrus sinensis), also suffer significantly from its effects. Research suggests that, despite species differences, the core physiological pathways involved in responding to low temperatures are remarkably con- served across various plant species. For example, all of these species trigger the generation of reactive oxygen species (ROS) and reactive nitrogen species (RNS), leading to oxidative and nitrosative stress, which in turn activate complex antioxidant and osmotic regulation systems [50]. Therefore, the in-depth mechanistic analysis conducted using cucumber as a model holds significant reference value for understanding the broader physiology of plant cold tolerance. Simultaneously, different crops (such as citrus, which accumulates anthocyanins in its fruits) may have evolved unique adaptive mechanisms, providing a complementary perspective for comprehensively mapping the plant cold resistance net- work. Meanwhile, emerging concepts such as “secondary metabolism (e.g., anthocyanin)” and “novel transcription factors” offer promising directions for the “Future Perspectives” section of this research [101]. Furthermore, exogenous substances (e.g., hormones, osmoprotectants, signaling molecules) show significant potential in alleviating low-temperature stress and promot- ing growth. Optimizing application strategies in conjunction with molecular breeding approaches will further enhance cold tolerance, providing sustainable solutions to the chal- lenges posed by climate change. In summary, with deepening research and technological progress, studies on cucumber cold-resistance mechanisms will advance, providing robust solutions for sustainable cucumber production. Author Contributions: Y.Z.: conceptualization, formal analysis, visualization, writing—original draft. H.H.: formal analysis, visualization, writing—original draft. M.S.: visualization, writing—original draft. A.C. and D.L.: validation, investigation. M.C.: formal analysis. W.L.: visualization, revised review. J.Y. Horticulturae 2025, 11, 1268 13 of 17 (Jiabao Ye): writing—review and editing, funding acquisition, supervision. J.Y. (Jiamei Yang): formal analysis. F.X.: writing—review and editing, supervision. All authors have read and agreed to the published version of the manuscript. Funding: This research was funded by the Key Research and Development Program of Hubei Province, China (No. 2024BBB018). Data Availability Statement: No new data were created or analyzed in this study. Conflicts of Interest: Authors Anjun Chen, Meng Chen, and Dujin Luo were employed by the company Hubei Xueyin Agricultural Science &Technology Co., Ltd., Jingzhou 434025, China. The remaining authors wish to disclose that, at the time of conducting this research and submitting the manuscript, they were not subject to any commercial or financial relationships that could be perceived as a potential conflict of interest.

  Advances in Physiological and Molecular Mechanisms of Cucumber Response to Low-Temperature Stress · 2025 · DOI

• Overall, this review summarized recent progress of SiNPs application in nano-enabled agriculture, focusing on synthesis, uptake and translocation, and application of SiNPs against various biotic and abiotic stresses. Based on these literatures, it can be concluded that SiNPs application is a cost-effective and multifunctional agronomic approach that is applicable to sustainable agriculture. However, several key issues need further investigation for the more widespread and reasonable usage of SiNPs in agricultural production including: (1) more effective synthesis approach of SiNPs using agricultural wastes; (2) the detailed effects of plant factors (e.g. plant species, plant structures and developmental stages) and SiNPs properties (e.g. size, charge property and specific modification) on the uptake and translocation of SiNPs; (3) the physiological and molecular basis of SiNPs- induced broad-spectrum resistance; (4) the effects and mechanisms of SiNPs modification on their delivery efficiency; (5) the main concerns over potential phytotoxicity induced from the application of SiNPs in agricultural ecosystem. 5.4 Synergistic effects of SiNPs in alleviating abiotic stress

  Silicon nanoparticles in sustainable agriculture: synthesis, absorption, and plant stress alleviation · 2024 · DOI

• The current evidence suggests that mainstreaming the use of Si substrate amendment to agricultural extension programs and design guidelines for urban green infrastructure is warranted.

  Harnessing Silicon-Based Growing Media for Sustainable Heavy Metal Remediation in Agricultural and Urban Green Systems: A Systematic Review · 2026 · DOI

• A single Silitec® application was associated with transient, compound- specific changes in the phenolic profile, while the roles of Si uptake, formulation, cultivar, and application timing remain to be resolved.

  Metabolic Responsiveness of Olive (Olea europaea L.) Cultivars Following Foliar Silicon Application: A Comparative LC–MS/MS Study · 2026 · DOI

• Plants have evolved diverse physiological and molecular mechanisms to cope with salinity, but salt tolerance varies widely among cultivars within the same species because of differences in genetic background and breeding/ adaptation history.

  Silicate-genotype interactions help improve stress tolerance of Glycine max and CO2 dynamics in saline soil · 2026 · DOI

• The linear reduction in substrate pH of plants irrigated with saline water, in response to increasing silicon doses (Figure 2A), is a complex phenomenon whose mechanisms are not yet fully understood.

  Silicon and potassium synergistically alleviate salt stress and enhance soil fertility, nutrition, and physiology of passion fruit seedlings · 2025 · DOI

• No pesticides were applied during this trial and future research should examine the use of Si in conjunction with pesticides and its possible value as a supplement to pesticide programs.

  The Beneficial Effects of Soluble Silicon Fertilizer in Dendrobium Orchids: Silicon-Augmented Resistance against Damage by Insect Pests and Fungal Pathogens · 2024 · DOI

• However, the mechanisms by which Si mediates rhizosphere metabolic reprogramming and microbial regulation to synergistically improve crop drought resilience remain unclear.

  Silicon fertilization drives metabolite–microbe synergy to stabilize rhizosphere nitrogen supply and improve drought resilience and yield stability in upland rice · 2026 · DOI

• Silicon (Si) amendment can achieve both objectives, yet the extent to which plant genotype modulates Si-based Cd mitigation effectiveness across different biological levels remains unclear.

  Silicon-mediated mitigation of cadmium risk in peanut-growing soil depends on cultivar-specific defense strategies · 2026 · DOI

• Silicon nanoparticles (Si NPs) are promising amendments for mitigating cadmium (Cd) toxicity and reducing Cd accumulation in crops, yet their dose-dependent effects on the rhizosphere microbiome remain unclear.

  Silicon nanoparticles promote soybean growth in Cd-contaminated soil by modulating soil bacterial networks · 2026 · DOI

• ), a C4 cereal crop domesticated in China, exhibits exceptional nitrogen use efficiency (NUtE) with marked genotypic variation; however, the molecular basis remains underexplored.

  SiLNR1 -Mediated Nitrogen Regulatory Signaling Enhances Nitrogen Use Efficiency and Grain Yield in Foxtail Millet ( Setaria italica L.) under Low-Nitrogen Stress · 2026 · DOI

• Although the silicon transport mechanisms in monocots are well characterized, the molecular basis of silicon deposition in dicots remains elusive.

  A molecular module controlling silicon efflux from glandular trichomes is required for fruit bloom formation in cucumber · 2025 · DOI

• However, the mechanisms regulating fruit bloom formation are not well understood.

  A molecular module controlling silicon efflux from glandular trichomes is required for fruit bloom formation in cucumber · 2025 · DOI

• However, the mechanisms by which BR alleviates salt stress during seed germination remain inadequately characterized.

  Multi-omics approach reveals the contribution of brassinosteroids to salt tolerance for seed germination in rice · 2025 · DOI

• However, the mechanisms by which CuNPs and SiNPs influence plant responses to root rot remain poorly understood.

  Physiological, transcriptomic and metabolomic analyses reveal the mechanism of CuO and silicon nanoparticles involved in Polygonatum kingianum response to root rot · 2025 · DOI

• Silicon (Si) and arbuscular mycorrhizal fungi (AMF) improve phosphorus (P) nutrition in crops, but the mechanisms underlying their interactive effects on P uptake by roots remain elusive.

  Interactions of silicon and arbuscular mycorrhizal fungi on phosphorus uptake during rice vegetative growth · 2025 · DOI

• Organic root exudate compounds (ORECs) can enhance mineral dissolution, releasing silicon (Si), but OREC-induced processes of Si solubilisation from different soil Si pools are poorly understood.

  Silicon solubilisation from soil minerals and soil by root exudate compounds · 2025 · DOI

• However, long-term soil erosion effects on phytolith pools in arable soils have not been analyzed along a soil catena yet.

  Effects of long-term soil erosion on phytolith assemblages along a catena in a temperate agricultural landscape · 2025 · DOI

• However, very little is known about the interactions between the weathering of soil minerals and the dissolution of Si by earthworms from phytoliths and subsequent Si uptake by plants.

  Impact of earthworms on soil Si availability and wheat Si concentration in low- and high-Si soils · 2024 · DOI

• Silicon fertilisers are widely utilised to achieve higher productivity in global terrestrial ecosystems, but their impact on the carbon cycle remains unclear.

  Silicon fertiliser application increases the terrestrial ecosystem carbon pool at the global scale · 2024 · DOI

• Phytoliths are an important component in the cycling of silicon (Si) in rice cultivation, yet little is known about their medium to long-term stability.

  Controls on phytolith stability upon exposure in paddy soils · 2024 · DOI

• While it is commonly accepted that phytolith solubility in soil decreases with time, the mechanisms that cause this decrease remain unclear.

  Controls on phytolith stability upon exposure in paddy soils · 2024 · DOI

• CONCLUSIONS: While phytolith morphology provides some distinction among palm clades, caution is warranted.

  Palms of the past: can morphometric phytolith analysis inform deep time evolution and palaeoecology of Arecaceae? · 2024 · DOI

• Although the resolution of taxonomic information they provide remains unclear, phytoliths (microscopic silica bodies) provide a possible solution because of their high preservation potential under conditions where other plant fossils are scarce.

  Palms of the past: can morphometric phytolith analysis inform deep time evolution and palaeoecology of Arecaceae? · 2024 · DOI

Most-cited papers in Silicon Effects in Agriculture

• Interactions of Silicon With Essential and Beneficial Elements in Plants · Frontiers in Plant Science · 2021 · 344 citations
• Preparation of Silica from Rice Husks · Journal of the American Ceramic Society · 1996 · 276 citations
• Functions of silicon in plant drought stress responses · Horticulture Research · 2021 · 253 citations
• Effects of silicon on heavy metal uptake at the soil-plant interphase: A review · Ecotoxicology and Environmental Safety · 2021 · 246 citations
• Silicon Cycling in Soils Revisited · Plants · 2021 · 241 citations
• Role of Silica Nanoparticles in Abiotic and Biotic Stress Tolerance in Plants: A Review · International Journal of Molecular Sciences · 2022 · 236 citations
• Effects of Silicon and Silicon-Based Nanoparticles on Rhizosphere Microbiome, Plant Stress and Growth · Biology · 2021 · 218 citations
• Impact of exogenous silicon addition on chromium uptake, growth, mineral elements, oxidative stress, antioxidant capacity, and leaf and root structures in rice seedlings exposed to hexavalent chromium · Acta Physiologiae Plantarum · 2011 · 210 citations
• Silicon-induced alleviation of NaCl toxicity in okra (Abelmoschus esculentus) is associated with enhanced photosynthesis, osmoprotectants and antioxidant metabolism · Acta Physiologiae Plantarum · 2015 · 177 citations
• Effect of foliar applications of silicon and titanium dioxide nanoparticles on growth, oxidative stress, and cadmium accumulation by rice (Oryza sativa) · Acta Physiologiae Plantarum · 2019 · 175 citations

Most recent work

• Beyond essentiality: silicon as a systems regulator of photosynthesis under stress scenarios · Frontiers in Plant Science · 2026
• Alleviating Effect of Silicon on Aluminum Toxicity in Plants · Agronomy · 2026
• Enhancing Cereal Crop Tolerance to Low-Phosphorus Conditions Through Fertilisation Strategies: The Role of Silicon in Mitigating Phosphate Deficiency · Agronomy · 2026
• Structural basis for a root silicon‐based barrier against cadmium, chromium, and salt stress in plants · New Phytologist · 2026
• Silicon fertilization drives metabolite–microbe synergy to stabilize rhizosphere nitrogen supply and improve drought resilience and yield stability in upland rice · Journal of Integrative Agriculture · 2026
• Maize cultivation and forest collapse over five centuries in southern China · Communications Earth & Environment · 2026
• Synergistic Application of Nano-micro and Macronutrients in Wheat Alleviated Drought Stress with Enhanced Physiological Response and Anti-oxidant Enzyme Activity · Journal of Plant Growth Regulation · 2026
• Seed Priming with Silicon Dioxide Nanoparticles Mediates Germination Indices and Pb-induced Oxidative Damage in Quinoa Seedlings Through NO Signaling · Journal of Plant Growth Regulation · 2026
• Growth, photosynthesis and biochemical responses of Juniperus excelsa seedlings to salicylic acid and silicon under salt stress · Forest Ecology and Management · 2026
• Role of silicon (Si) in the modulation of phenylpropanoid metabolism and lignin biosynthesis in arsenic (As)-treated different maize root categories · Plant and Soil · 2026

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