Silicon mediated abiotic stress tolerance in plants using physio-biochemical, omic approach and cross-talk with phytohormones

Melatonin Interaction with Other Phytohormones in the Regulation of Abiotic Stresses in Horticultural Plants

Horticultural crops play a vital role in global food production, nutrition, and the economy. Horticultural crops are highly vulnerable to abiotic stresses. These abiotic stresses hinder plant growth and development by affecting seed germination, impairing photosynthetic activity, and damaging root development, thus leading to a decrease in fruit yield, quality, and productivity. Scientists have conducted extensive research to investigate the mechanisms of resilience and the ability to cope with environmental stresses. In contrast, the use of phytohormones to alleviate the detrimental impacts of abiotic stresses on horticulture plants has been generally recognized as an effective method. Among phytohormones, melatonin (MT) is a novel plant hormone that regulates various plants' physiological functions such as seedling development, root system architecture, photosynthetic efficiency, balanced redox homeostasis, secondary metabolites production, accumulation of mineral nutrient uptake, and activated antioxidant defense system. Importantly, MT application significantly restricted heavy metals (HMs) uptake and increased mineral nutrient accumulation by modifying the root architecture system. In addition, MT is a naturally occurring, multifunctional, nontoxic biomolecule having antioxidant properties. Furthermore, this review described the hormonal interaction between MT and other signaling molecules in order to enhance abiotic stress tolerance in horticulture crops. This review focuses on current research advancements and prospective approaches for enhancing crop tolerance to abiotic stress.

Silicon: A valuable soil element for improving plant growth and CO2 sequestration

BACKGROUND

Silicon (Si), the second most abundant and quasi-essential soil element, is locked as a recalcitrant silicate mineral in the Earth's crust. The physical abundance of silicates can play an essential role in increasing plant productivity. Plants store Si as biogenic silica (phytoliths), which is mobilized through a chemical weathering process in the soil.

AIM OF REVIEW

Although Si is a critical element for plant growth, there is still a considerable need to understand its dissolution, uptake, and translocation in agroecosystems. Here, we show recent progress in understanding the interactome of Si, CO2, the microbiome, and soil chemistry, which can sustainably govern silicate dissolution and cycling in agriculture.

KEY SCIENTIFIC CONCEPTS OF THIS REVIEW

Si cycling is directly related to carbon cycling, and the resulting climate stability can be enhanced by negative feedback between atmospheric CO2 and the silicate uptake process. Improved Si mobilization in the rhizosphere by the presence of reactive elements (for example, Ca, Na, Al, Zn, and Fe) and Si uptake through genetic transporters in plants are crucial to achieving the dual objectives of (i) enhancing crop productivity and (ii) abiotic stress tolerance. Furthermore, the microbiome is a symbiotic partner of plants. Bacterial and fungal microbiomes can solubilize silicate minerals through intriguingly complex bioweathering mechanisms by producing beneficial metabolites and enzymes. However, the interaction of Si with CO2 and the microbiome's function in mobilization have been understudied. This review shows that enhancing our understanding of Si, CO2, the microbiome, and soil chemistry can help in sustainable crop production during climatic stress events.

Silicon regulates phosphate deficiency through involvement of auxin and nitric oxide in barley roots

MAIN CONCLUSION

Silicon application mitigates phosphate deficiency in barley through an interplay with auxin and nitric oxide, enhancing growth, photosynthesis, and redox balance, highlighting the potential of silicon as a fertilizer for overcoming nutritional stresses. Silicon (Si) is reported to attenuate nutritional stresses in plants, but studies on the effect of Si application to plants grown under phosphate (Pi) deficiency are still very scarce, especially in barley. Therefore, the present work was undertaken to investigate the potential role of Si in mitigating the adverse impacts of Pi deficiency in barley Hordeum vulgare L. (var. BH902). Further, the involvement of two key regulatory signaling molecules--auxin and nitric oxide (NO)--in Si-induced tolerance against Pi deficiency in barley was tested. Morphological attributes, photosynthetic parameters, oxidative stress markers (O2·-, H2O2, and MDA), antioxidant system (enzymatic--APX, CAT, SOD, GR, DHAR, MDHAR as well as non-enzymatic--AsA and GSH), NO content, and proline metabolism were the key traits that were assessed under different treatments. The P deficiency distinctly declined growth of barley seedlings, which was due to enhancement in oxidative stress leading to inhibition of photosynthesis. These results were also in parallel with an enhancement in antioxidant activity, particularly SOD and CAT, and endogenous proline level and its biosynthetic enzyme (P5CS). The addition of Si exhibited beneficial effects on barley plants grown in Pi-deficient medium as reflected in increased growth, photosynthetic activity, and redox balance through the regulation of antioxidant machinery particularly ascorbate-glutathione cycle. We noticed that auxin and NO were also found to be independently participating in Si-mediated improvement of growth and other parameters in barley roots under Pi deficiency. Data of gene expression analysis for PHOSPHATE TRANSPORTER1 (HvPHT1) indicate that Si helps in increasing Pi uptake as per the need of Pi-deficient barley seedlings, and also auxin and NO both appear to help Si in accomplishing this task probably by inducing lateral root formation. These results are suggestive of possible application of Si as a fertilizer to correct the negative effects of nutritional stresses in plants. Further research at genetic level to understand Si-induced mechanisms for mitigating Pi deficiency can be helpful in the development of new varieties with improved tolerance against Pi deficiency, especially for cultivation in areas with Pi-deficient soils.

Silicon a key player to mitigate chromium toxicity in plants: Mechanisms and future prospective

Chromium is a serious heavy metal (HM) and its concentration in plant-soil interface is soaring due to anthropogenic activities, unregulated disposals, and lack of efficient treatments. High concentration of Cr is toxic to ecosystems and human health. Cr stress also diminishes the plant performance by changing the plant's vegetative and reproductive development that ultimately affects sustainable crop production. Silicon (Si) is the second-most prevalent element in the crust of the planet, and has demonstrated a remarkable potential to minimize the HM toxicity. Amending soils with Si mitigates adverse effects of Cr by improving plant physiological, biochemical, and molecular functioning and ensuring better Cr immobilization, compartmentation, and co-precipitation. However, there is no comprehensive review on the role of Si to mitigate Cr toxicity in plants. Thus, in this present review; the discussion has been carried on; 1) the source of Cr, 2) underlying mechanisms of Cr uptake by plants, 3) how Si affects the plant functioning to reduce Cr toxicity, 4) how Si can cause immobilization, compartmentation, and co-precipitation 5) strategies to improve Si accumulation in plants to counter Cr toxicity. We also discussed the knowledge gaps and future research needs. The present review reports up-to-date knowledge about the role of Si to mitigate Cr toxicity and it will help to get better crop productivity in Cr-contaminated soils. The findings of the current review will educate the readers on Si functions in reducing Cr toxicity and will offer new ideas to develop Cr tolerance in plants through the use of Si.

Multiomics Explore the Detoxification Mechanism of Nanoselenium and Melatonin on Bensulfuron Methyl in Wheat Plants

Combining nanoselenium (nano-Se) and melatonin (MT) was more effective than treatment alone against abiotic stress. However, their combined application mitigated the toxic effects of bensulfuron methyl, and enhanced wheat growth and metabolism has not been studied. Metabolomics and proteomics revealed that combining nano-Se and MT markedly activated phenylpropanoid biosynthesis pathways, elevating the flavonoid (quercetin by 33.5 and 39.8%) and phenolic acid (vanillic acid by 38.8 and 48.7%) levels in leaves and roots of wheat plants. Interstingly, beneficial rhizosphere bacteria in their combination increased (Oxalobacteraceae, Nocardioidaceae, and Xanthomonadaceae), which positively correlated with the enhancement of soil urease and fluorescein diacetate enzyme activity (27.0 and 26.9%) and the allelopathic substance levels. To summarize, nano-Se and MT mitigate the adverse effects of bensulfuron methyl by facilitating interactions between the phenylpropane metabolism of the plant and the beneficial microbial community. The findings provide a theoretical basis for using nano-Se and MT to remediate herbicide-contaminated soil.

Silicon nanoparticles confer hypoxia tolerance in citrus rootstocks by modulating antioxidant activities and carbohydrate metabolism

Citrus is a remarkable fruit crop, extremely sensitive to flooding conditions, which frequently trigger hypoxia stress and cause severe damage to citrus plants. Silicon nanoparticles (SiNPs) are beneficial and have the potential to overcome this problem. Therefore, the present study aimed to investigate the effect of silicon nanoparticles to overcome hypoxia stress through modulating antioxidant enzyme activity and carbohydrate metabolism. Three citrus rootstocks (Carrizo citrange, Roubidoux, and Rich 16-6) were exposed to flooding (with and without oxygen) through different SiNP treatments via foliar and root zone. SiNPs applied treatment plants showed a significant increase in photosynthesis, leaf greenness, antioxidant enzymes, and carbohydrate metabolic activities, besides the higher accumulation of proline and glycine betaine. The rate of lipid peroxidation was drastically higher in flooded plants; however, SiNPs application reduced it significantly, ultimately reducing oxidative damage. Overall, Rich16-6 rootstock showed good performance via root zone application compared to other rootstocks, possibly due to genotypical variation in silicon uptake. Our outcomes demonstrate that SiNPs significantly affect plant growth during hypoxia stress conditions, and their use is an optimal strategy to overcome this issue. This study laid the foundation for future research to use at the commercial level to overcome hypoxia stress and a potential platform for future research.

The silicon regulates microbiome diversity and plant defenses during cold stress in Glycine max L

Introduction

With climate change, frequent exposure of bioenergy and food crops, specifically soybean (Glycine max L.), to low-temperature episodes is a major obstacle in maintaining sustainable plant growth at early growth stages. Silicon (Si) is a quasi-essential nutrient that can help to improve stress tolerance; however, how Si and a combination of cold stress episodes influence plant growth, plant physiology, and microbiome diversity has yet to be fully discovered.

Methods

The soybean plants were exposed to cold stress (8-10°C) with or without applying Si, and the different plant organs (shoot and root) and rhizospheric soil were subjected to microbiome analysis. The plant growth, physiology, and gene expression analysis of plant defenses during stress and Si were investigated.

Results and discussion

We showed that cold stress significantly retarded soybean plants' growth and biomass, whereas, Si-treated plants showed ameliorated negative impacts on plant growth at early seedling stages. The beneficial effects of Si were also evident from significantly reduced antioxidant activities - suggesting lower cold-induced oxidative stress. Interestingly, Si also downregulated critical genes of the abscisic acid pathway and osmotic regulation (9-cis-epoxy carotenoid dioxygenase and dehydration-responsive element binding protein) during cold stress. Si positively influenced alpha and beta diversities of bacterial and fungal microbiomes with or without cold stress. Results showed significant variation in microbiome composition in the rhizosphere (root and soil) and phyllosphere (shoot) in Si-treated plants with or without cold stress exposures. Among microbiome phyla, Proteobacteria, Bacteroidota, and Ascomycota were significantly more abundant in Si treatments in cold stress than in control conditions. For the core microbiome, we identified 179 taxa, including 88 unique bacterial genera in which Edaphobacter, Haliangium, and Streptomyces were highly abundant. Enhanced extracellular enzyme activities in the cold and Si+cold treatments, specifically phosphatase and glucosidases, also reflected the microbiome abundance. In conclusion, this work elucidates cold-mediated changes in microbiome diversity and plant growth, including the positive impact Si can have on cold tolerance at early soybean growth stages - a step toward understanding crop productivity and stress tolerance.

Deciphering the mechanisms, hormonal signaling, and potential applications of endophytic microbes to mediate stress tolerance in medicinal plants

The global healthcare market in the post-pandemic era emphasizes a constant pursuit of therapeutic, adaptogenic, and immune booster drugs. Medicinal plants are the only natural resource to meet this by supplying an array of bioactive secondary metabolites in an economic, greener and sustainable manner. Driven by the thrust in demand for natural immunity imparting nutraceutical and life-saving plant-derived drugs, the acreage for commercial cultivation of medicinal plants has dramatically increased in recent years. Limited resources of land and water, low productivity, poor soil fertility coupled with climate change, and biotic (bacteria, fungi, insects, viruses, nematodes) and abiotic (temperature, drought, salinity, waterlogging, and metal toxicity) stress necessitate medicinal plant productivity enhancement through sustainable strategies. Plants evolved intricate physiological (membrane integrity, organelle structural changes, osmotic adjustments, cell and tissue survival, reclamation, increased root-shoot ratio, antibiosis, hypersensitivity, etc.), biochemical (phytohormones synthesis, proline, protein levels, antioxidant enzymes accumulation, ion exclusion, generation of heat-shock proteins, synthesis of allelochemicals. etc.), and cellular (sensing of stress signals, signaling pathways, modulating expression of stress-responsive genes and proteins, etc.) mechanisms to combat stresses. Endophytes, colonizing in different plant tissues, synthesize novel bioactive compounds that medicinal plants can harness to mitigate environmental cues, thus making the agroecosystems self-sufficient toward green and sustainable approaches. Medicinal plants with a host set of metabolites and endophytes with another set of secondary metabolites interact in a highly complex manner involving adaptive mechanisms, including appropriate cellular responses triggered by stimuli received from the sensors situated on the cytoplasm and transmitting signals to the transcriptional machinery in the nucleus to withstand a stressful environment effectively. Signaling pathways serve as a crucial nexus for sensing stress and establishing plants' proper molecular and cellular responses. However, the underlying mechanisms and critical signaling pathways triggered by endophytic microbes are meager. This review comprehends the diversity of endophytes in medicinal plants and endophyte-mediated plant-microbe interactions for biotic and abiotic stress tolerance in medicinal plants by understanding complex adaptive physiological mechanisms and signaling cascades involving defined molecular and cellular responses. Leveraging this knowledge, researchers can design specific microbial formulations that optimize plant health, increase nutrient uptake, boost crop yields, and support a resilient, sustainable agricultural system.

Combined application of SiO2 and TiO2 nanoparticles enhances growth characters, physiological attributes and essential oil production of Coleus aromatics Benth

Nanoparticles (NPs) have gained considerable interest among researchers in the field of plant biology, particularly in the agricultural sector. Among the numerous NPs, the individual application of silicon (Si) or titanium (Ti), in their oxide forms, had a positive influence on growth, physiochemical and yield attributes of plants. However, the synergetic application of both these NPs has not been studied yet. Therefore, the current study was aimed to investigate the effect of combined application of silicon dioxide (SiO2) and titanium dioxide (TiO2) NPs on the growth characters, physiological parameters, and essential oil quality and production of Coleus aromatics Benth. Aqueous solutions of nanoparticles were applied to the foliage of the plants at varying combinations (Si50+Ti50, Si100+Ti50, Si100+Ti100, Si200+Ti100, Si100+Ti200 and Si200+Ti200 mg L-1). Various morpho-physiological, biochemical and yield attributes were assessed at 120 days after planting. The results demonstrated that both Si and Ti NPs improved the growth and photosynthetic efficiency in a dose dependent manner. The best results were obtained by the combined application of Si100+Ti100 mg L-1, and thereafter, the values declined progressively. The maximum improvement in fresh weight (39.5 %) and dry weight (40.8 %) of shoot, fresh weight (45.7 %) and dry weight (49.4 %) of root was observed as compared to respective controls. Moreover, the exogenous application of Si100+Ti100 mg L-1 increased photosynthetic attributes such as total content of chlorophyll (41.7 %), carotenoids (43.7 %), chlorophyll fluorescence (7.1 %), and carbonic anhydrase (23.8 %). All of these contributed to the highest accumulation in the content (129.0 %) and yield (215.5 %) of essential oil (EO), in comparison to the control. Thus, results encouraged the use of SiO2 and TiO2 NPs to be applied in combined form to boost the essential oil production of Coleus aromaticus. The findings of this study may serve agronomists to determine the optimal concentrations of NPs for enhanced production of bioactive compounds with a wide range of industrial applications.

Silicon nanoparticles in higher plants: Uptake, action, stress tolerance, and crosstalk with phytohormones, antioxidants, and other signalling molecules

Silicon is absorbed as uncharged mono-silicic acid by plant roots through passive absorption of Lsi1, an influx transporter belonging to the aquaporin protein family. Lsi2 then actively effluxes silicon from root cells towards the xylem from where it is exported by Lsi6 for silicon distribution and accumulation to other parts. Recently, it was proposed that silicon nanoparticles (SiNPs) might share a similar route for their uptake and transport. SiNPs then initiate a cascade of morphophysiological adjustments that improve the plant physiology through regulating the expression of many photosynthetic genes and proteins along with photosystem I (PSI) and PSII assemblies. Subsequent improvement in photosynthetic performance and stomatal behaviour correspond to higher growth, development, and productivity. On many occasions, SiNPs have demonstrated a protective role during stressful environments by improving plant-water status, source-sink potential, reactive oxygen species (ROS) metabolism, and enzymatic profile. The present review comprehensively discusses the crop improvement potential of SiNPs stretching their role during optimal and abiotic stress conditions including salinity, drought, temperature, heavy metals, and ultraviolet (UV) radiation. Moreover, in the later section of this review, we offered the understanding that most of these upgrades can be explained by SiNPs intricate correspondence with phytohormones, antioxidants, and signalling molecules. SiNPs can modulate the endogenous phytohormones level such as abscisic acid (ABA), auxins (IAAs), cytokinins (CKs), ethylene (ET), gibberellins (GAs), and jasmonic acid (JA). Altered phytohormones level affects plant growth, development, and productivity at various organ and tissue levels. Similarly, SiNPs regulate the activities of catalase (CAT), ascorbate peroxidase (APX), superoxide dismutase (SOD), and ascorbate-glutathione (AsA-GSH) cycle leading to an upgraded defence system. At the cellular and subcellular levels, SiNPs crosstalk with various signalling molecules such as Ca²⁺, K⁺, Na⁺, nitric oxide (NO), ROS, soluble sugars, and transcription factors (TFs) was also explained.

Impact of 24-epibrassinolide, spermine, and silicon on plant growth, antioxidant defense systems, and osmolyte accumulation of maize under water stress

The effect of triad application of the phytohormone 24-epibrassinolide (EBL), the polyamine spermine (Spm), and the element silicon (Si) has not yet been considered on plant growth and behavior in water-stressed conditions. We aimed to evaluate the impact of single/dual/triad application of 24-epibrassinolide (EBL), spermine (Spm), and silicon (Si) on the growth, photosynthetic metabolites, and antioxidant enzymes in the maize plant exposed to water stress. This study was conducted as a potential drought resistance system and plants' maintenance against oxidative damage. In this regard, one maize hybrid (Paya) was grown under well-watered and water-deficit conditions (interrupted irrigation at the flowering and the filling seed stages) with and without foliar spraying of EBL, Spm, and/or Si. Drought conditions remarkably reduced growth, productivity, water-related content (RWC), and chlorophyll content. However, the dual and triad applications of EBL (0.1 mg L^-1), Spm (25 mg L^-1), and Si (7 mg L^-1) significantly improved the above parameters. Water stress considerably augmented the levels of H₂O₂ and MDA. Their content in stress-subjected plants was significantly reduced by triad application. In water-stressed circumstances and after foliar treatments, the activities of superoxide dismutase, catalase, and peroxidase as well as the amounts of total soluble proteins, phenolic compounds, proline, and glycine betaine all improved. Overall, triad application increased the plant's drought resistance and diminished ROS accumulation by raising the scavenging via the enhanced activity of the antioxidant enzymes.

Sodium silicate promotes wound healing by inducing the deposition of suberin polyphenolic and lignin in potato tubers

Wound healing is a postharvest characteristic of potato tubers through accumulating suberin and lignin, which could reduce decay and water loss during storage. This study aimed to explore the impact and mechanisms of sodium silicate on wound healing of potatoes. After being wounded, "Atlantic" potato tubers were treated with water or 50 mM sodium silicate. The results showed that sodium silicate treatment accelerated the formation of wound healing structures and significantly reduced the weight loss and disease index of tubers. Furthermore, sodium silicate induced the genes expression and enzyme activity of phenylalanine ammonia lyase (PAL), 4-coumarate: coenzyme A ligase (4CL), and cinnamyl alcohol dehydrogenase (CAD) involved in the phenylpropane metabolism, enhancing the synthesis of the main precursors of suberin polyphenolic (SPP) and lignin, such as coniferyl alcohol, sinapyl alcohol, and cinnamyl alcohol. Meanwhile, the gene expression of StPOD and StNOX was activated, and the production of O^2- and H₂O₂ was promoted, which could be used for injury signal transmission and oxidative crosslinking of SPP monomers and lignin precursors. Besides, antimicrobial compounds, total phenolics, and flavonoids were also induced. We suggest that sodium silicate could promote wound healing by inducing the deposition of SPP, lignin, and antimicrobial compounds in potato tubers.

Exogenous silicon alleviates the adverse effects of cinnamic acid-induced autotoxicity stress on cucumber seedling growth

Autotoxicity is a key factor that leads to obstacles in continuous cropping systems. Although Si is known to improve plant resistance to biotic and abiotic stresses, little is known about its role in regulating leaf water status, mineral nutrients, nitrogen metabolism, and root morphology of cucumber under autotoxicity stress. Here, we used cucumber seeds (Cucumis sativus L. cv. "Xinchun No. 4") to evaluate how exogenous Si (1 mmol L^-1) affected the leaf water status, mineral nutrient uptake, N metabolism-related enzyme activities, root morphology, and shoot growth of cucumber seedlings under 0.8 mmol L^-1 CA-induced autotoxicity stress. We found that CA-induced autotoxicity significantly reduced the relative water content and water potential of leaves and increase their cell sap concentration. CA-induced stress also inhibited the absorption of major (N, P, K, Ca, Mg) and trace elements (Fe, Mn, Zn). However, exogenous Si significantly improved the leaf water status (relative water content and water potential) of cucumber leaves under CA-induced stress. Exogenous Si also promoted the absorption of mineral elements by seedlings under CA-induced stress and alleviated the CA-induced inhibition of N metabolism-related enzyme activities (including nitrate reductase, nitrite reductase, glutamine synthetase, glutamate synthase, glutamate dehydrogenase). Moreover, exogenous Si improved N uptake and utilization, promoted root morphogenesis, and increased the growth indexes of cucumber seedlings under CA-induced stress. Our findings have far-reaching implications for overcoming the obstacles to continuous cropping in cucumber cultivation.

Transcriptome Analysis of Endogenous Hormone Response Mechanism in Roots of Styrax tonkinensis Under Waterlogging

As a promising oil species, Styrax tonkinensis has great potential as a biofuel due to an excellent fatty acid composition. However, frequent flooding caused by global warming and the low tolerance of the species to waterlogging largely halted its expansion in waterlogged areas. To explore endogenous hormones and phytohormone-related molecular response mechanism of S. tonkinensis under waterlogging, we determined 1-aminocyclopropane-1-carboxylic acid (ACC) and three phytohormone content (ABA, abscisic acid; SA, salicylic acid; IAA, indole-3-acetic acid) and analyzed the transcriptome of its seedlings under waterlogged condition of 3-5 cm. The sample collecting time was 0, 9, 24, and 72 h, respectively. It was concluded that ACC presented an upward trend, but other plant hormones showed a downward trend from 0 to 72 h under waterlogging stress. A total of 84,601 unigenes were assembled with a total length of 81,389,823 bp through transcriptome analysis. The GO enrichment analysis of total differentially expressed genes (DEGs) revealed that 4,637 DEGs, 8,238 DEGs, and 7,146 DEGs were assigned into three main GO functional categories in 9 vs. 0 h, 24 vs. 0 h, and 72 vs. 0 h, respectively. We also discovered several DEGs involved in phytohormone synthesis pathway and plant hormone signaling pathway. It was concluded that the decreased transcription of PYL resulted in the weak ABA signal transduction pathway. Moreover, decreased SA content caused by the low-expressed PAL might impact the resistance of S. tonkinensis seedlings under waterlogging stress. Our research may provide a scientific basis for the understanding of the endogenous hormone response mechanism of S. tonkinensis to waterlogging and lay a foundation for further exploration of the waterlogging defect resistance genes of S. tonkinensis and improving its resistance to waterlogging stress.

Multidimensional Role of Silicon to Activate Resilient Plant Growth and to Mitigate Abiotic Stress

Sustainable agricultural production is critically antagonistic by fluctuating unfavorable environmental conditions. The introduction of mineral elements emerged as the most exciting and magical aspect, apart from the novel intervention of traditional and applied strategies to defend the abiotic stress conditions. The silicon (Si) has ameliorating impacts by regulating diverse functionalities on enhancing the growth and development of crop plants. Si is categorized as a non-essential element since crop plants accumulate less during normal environmental conditions. Studies on the application of Si in plants highlight the beneficial role of Si during extreme stressful conditions through modulation of several metabolites during abiotic stress conditions. Phytohormones are primary plant metabolites positively regulated by Si during abiotic stress conditions. Phytohormones play a pivotal role in crop plants' broad-spectrum biochemical and physiological aspects during normal and extreme environmental conditions. Frontline phytohormones include auxin, cytokinin, ethylene, gibberellin, salicylic acid, abscisic acid, brassinosteroids, and jasmonic acid. These phytohormones are internally correlated with Si in regulating abiotic stress tolerance mechanisms. This review explores insights into the role of Si in enhancing the phytohormone metabolism and its role in maintaining the physiological and biochemical well-being of crop plants during diverse abiotic stresses. Moreover, in-depth information about Si's pivotal role in inducing abiotic stress tolerance in crop plants through metabolic and molecular modulations is elaborated. Furthermore, the potential of various high throughput technologies has also been discussed in improving Si-induced multiple stress tolerance. In addition, a special emphasis is engrossed in the role of Si in achieving sustainable agricultural growth and global food security.