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Functions of silicon in plant drought stress responses

Abstract

Silicon (Si), the second most abundant element in Earth’s crust, exerts beneficial effects on the growth and productivity of a variety of plant species under various environmental conditions. However, the benefits of Si and its importance to plants are controversial due to differences among the species, genotypes, and the environmental conditions. Although Si has been widely reported to alleviate plant drought stress in both the Si-accumulating and nonaccumulating plants, the underlying mechanisms through which Si improves plant water status and maintains water balance remain unclear. The aim of this review is to summarize the morphoanatomical, physiological, biochemical, and molecular processes that are involved in plant water status that are regulated by Si in response to drought stress, especially the integrated modulation of Si-triggered drought stress responses in Si accumulators and intermediate- and excluder-type plants. The key mechanisms influencing the ability of Si to mitigate the effects of drought stress include enhancing water uptake and transport, regulating stomatal behavior and transpirational water loss, accumulating solutes and osmoregulatory substances, and inducing plant defense- associated with signaling events, consequently maintaining whole-plant water balance. This study evaluates the ability of Si to maintain water balance under drought stress conditions and suggests future research that is needed to implement the use of Si in agriculture. Considering the complex relationships between Si and different plant species, genotypes, and the environment, detailed studies are needed to understand the interactions between Si and plant responses under stress conditions.

Introduction

Silicon (Si) is the second most abundant mineral element present in the soil, and silicon dioxide composes approximately 50–70% of the soil mass1,2,3,4. Si has various ecological functions, with complex roles in plant processes and in mediating interactions with the environment and other organisms5,6,7. Si accumulation varies greatly among plant species, ranging from 0.1 to 10% dry weight. Based on the Si content in tissues, plants can be classified as accumulator (e.g., rice, wheat, maize, and sorghum), intermediate (e.g., cucumber, bitter gourd, and melon), or excluder (e.g., tomato, potato, canola, and lentil) types8,9. The differences are attributed to the different modes of Si uptake (active, passive, and rejective)10,11. In addition, these differences are largely due to the abilities of the roots of various plant species to absorb Si4, which is related to Si transporter expression and function. Below a pH of nine, Si is generally taken up by plant roots in the form of silicic acid [Si(OH)4], an uncharged monomeric molecule4 that is dependent primarily on a specific Si influx transporter (Lsi1) and a specific efflux transporter (Lsi2). Another influx transporter, Lsi6, regulates the unloading of Si from the xylem to leaf tissues and further facilitates root-to-shoot translocation4,12,13. In addition to Si taken up by roots, Si fertilizer can also be efficiently supplied to leaves to increase plant dry matter production14,15,16,17 and is absorbed mainly via cuticular pathways, stomata, and trichomes18. Foliar application of Si-containing solutions is a viable alternative Si fertilization method to increase Si accumulation, especially for intermediate and Si nonaccumulator plants15,16,19,20.

During their growth and development, plants are subjected to various environmental stresses. Si has been widely reported to enhance plant tolerance to various abiotic and biotic stresses, such as drought, salt, freezing, nutrient imbalance, radiation damage, metal toxicity, pests, and pathogens5,21,22,23,24,25,26. Drought, a recurring phenomenon with major impacts on both humans and natural ecosystems, is the most widespread climatic extreme that hinders primarily crop growth and productivity27. In this context, the alleviating effects of Si on drought stress has been observed in a wide variety of crop plants species, including both monocots (e.g., rice, wheat, maize, and sorghum) and dicots (e.g., tomato, cucumber, sunflower, soybean, cotton, mango, and canola)28,29,30,31,32,33,34,35,36,37,38. Interestingly, Si has been shown to counteract the effects of drought stress in plant species that have a weakly ability to accumulate Si (Si excluders), such as tomato and canola. Additionally, wheat landraces that were high Si accumulators had higher levels of shoot Si compared to low accumulators, but no differences in growth or stress tolerance were observed underwater stress39. This suggests that the effects of Si are not proportional to its accumulation in plants and that a low amount of Si accumulation does not equate to poor function40. The role of Si in low Si-accumulating plants is attributed mainly to the biochemical function of Si, while mechanical/physical barriers induced by Si deposition in high Si-accumulating plants are important for the stress response7,32,41. For example, Si also was shown to induce resistance to bacterial wilt disease caused by Ralstonia solanacearum in Si-nonaccumulating tomato plants, which was mediated mainly via signaling pathways, such as those involving ethylene (ET), jasmonic acid (JA), and/or reactive oxygen species (ROS)42.

Although Si is not considered an essential element for plants, it is well known to be beneficial for plant growth and development, especially under stress conditions2,5,43. Si stimulates seed germination in wheat, maize, lentil, and tomato under drought stress41,44,45,46, the effects of which are attributed to the increased antioxidant defense and decreased oxidative stress induced by Si41,47. During plant growth, Si has been found to increase plant biomass and grain yields of several crop species under drought stress29,35,48,49, which is attributed to increases in total root length, surface area, and volume as well as increases in plant height, dry matter, panicle length, and tiller number28,48,50. Another important feature due to the possible role of Si is reducing spikelet sterility and subsequently increasing the grain yields of rice supplied with Si28,48,50.

Given the obvious benefits of Si on drought tolerance (Fig. 1), it may be expected that its process has been extensively characterized. However, the detailed mechanisms remain unknown and appear to vary according to genotype and environment. In this review, the morphoanatomical, physiological, biochemical, and molecular processes by which Si alleviates plant drought stress, especially the potential functions of Si in the accumulator, intermediate, and excluder plants, are summarized. This study provides an overview of the currently available information on Si-mediated root water uptake, leaf water loss, and plant defense responses under drought stress.

Fig. 1: Beneficial effects of silicon (Si) on the growth and development of plants under drought stress.
figure 1

a Plant growth and yield production in the absence of Si application (-Si). Seed germination, root growth, shoot growth, and crop yields are suppressed by drought without Si application. b Plant growth and yield production in the presence of Si application (+Si). c The beneficial effects of Si under drought stress include stimulating seed germination (1) and increasing both root (2) and shoot growth (3), thus increasing plant biomass and yield (4) under drought stress

Si increases root water uptake under drought stress

Improving root/shoot ratios

Increasing root water uptake by regulating the root surface and anatomy is important for plant stress tolerance51. Si is essential for root development and water uptake under drought stress conditions49,52. It was suggested that Si application regulates polyamine (PA) and 1-aminocyclopropane-1-carboxylic acid (ACC) levels under drought stress conditions to increase root growth and the root/shoot ratio53, thus improving root water uptake28,32,53,54,55,56. Such Si-mediated changes in root development also increase root endodermal silicification and suberization54,55, therefore enhancing the capability of water retention to overcome the effects of drought stress. Root endodermal development involves three main stages: Casparian band formation, deposition of suberin lamellae, and thickening of cell walls. Si has been shown to promote Casparian band development by crosslinking phenols with the cell wall or by inducing precipitation of phenols56. Endodermal silicification associated with cell walls in the roots is arranged in a specific pattern that initiates in endodermal cells adjacent to the phloem, continues to the xylem poles, and is ultimately observed in so-called passage cells57. However, in a study of sorghum, endodermal silicification-induced drought resistance was not driven through an improved root water retention capability, and root silicification might help overcome drought stress by decreasing root growth inhibition caused by desiccation58.

In contrast, several researchers have reported no effects of Si on the root/shoot ratio but have reported increases in both the root and shoot dry weight under stress conditions32,52,59, and these authors suggested that Si was effective at improving plant resistance to osmotic stress and that root hydraulic conductance is important for Si-promoted root water uptake31. Thus, Si-enhanced water uptake under drought stress conditions could be specific to plant species, genotype, or even environmental conditions. In the following section, the functions of Si in water uptake and transport are discussed.

Promoting the root osmotic driving force

Osmotic adjustment and accumulation of compatible cellular solutes are considered plant physiological processes that occur in response to drought stress60,61. These adjustments are attributed mainly to turgor maintenance and the protection of specific cellular functions by the accumulation of compatible organic solutes such as amino acids, soluble sugars, and minerals62,63, resulting in a favorable osmotic gradient between the plant roots and the growth medium to facilitate water uptake51,64,65.

An increasing number of studies have indicated that applying Si promotes osmolyte accumulation in many plant species, especially Si accumulators, such as rice, wheat, maize, and sorghum, under drought stress28,29,30,66, thus improving the osmotic driving force for water uptake66. In line with this point, Si has been reported to regulate the activities of enzymes involved in carbohydrate metabolism and affect the lignification of cell walls, consequently regulating assimilate synthesis and transport efficiency28,29,30,38,66,67,68. Other osmotic responses are exhibited by cucumber and wheat plants, which show increased protein content when exposed to salt and drought stress together with Si29,69, and also in chickpea and sunflower plants, in which proline accumulation is induced by Si under drought stress34,70. The accumulation of these osmolytes involves not only osmotic adjustment but also detoxification of ROS, maintenance of membrane integrity, and stabilization of proteins/enzymes, which contribute to drought tolerance. However, another study in tomato (a Si excluder) showed that osmotic events were not affected by Si under drought32, suggesting that the Si-mediated increase in root water uptake was not due to an increase in the osmotic driving force under drought stress but rather was due to an improved root hydraulic conductance. In addition, Si application alleviated drought stress by decreasing the content of osmolytes in lentil and potato plant species (Si excluders)46,67, suggesting that the role of the osmotic driving force in Si-mediated improvement of water uptake differs between the Si accumulators and excluders. Therefore, the osmotic driving force was not the only important response, and the role of the osmotic driving force in the Si-mediated enhancement of water uptake does not appear to be deployed in all situations.

The abovementioned studies implied that Si application increased plant drought tolerance by regulating osmotic adjustments based on organic solute accumulation. However, since little is known about the mechanisms of Si-mediated osmotic adjustment in plants, the relationship between the Si application and plant-compatible solute metabolism needs future investigation, especially the difference between the Si accumulators and excluders.

Increasing root hydraulic conductance

The root water uptake capacity is largely determined by hydraulic conductance71, and Si application has been reported to improve root hydraulic conductance in Si accumulators, intermediates, and excluders plants underwater and salt stress31,32,59,66,72,73,74,75. Root hydraulic conductance can be inhibited by high exogenous hydrogen peroxide (H2O2) levels, which are correlated with membrane electrolyte leakage and ROS levels76. H2O2 is involved in the formation of suberin lamellae, which form a hydrophobic barrier in the endodermis and exodermis of roots77. Under stress conditions, Si application reduces H2O2 production and suberin lamella formation and further induces increased water permeability32. In tomato plants under drought stress, root plasma membrane integrity was improved in response to Si application, and negative correlations were found between root hydraulic conductance and the levels of both the ROS and lipid peroxidation products32. The Si-mediated alleviation of ROS production under drought stress corresponded with an increase in antioxidant defenses, mainly attributed to the improved activity of catalase (CAT) and superoxide dismutase (SOD), as well as contents of ascorbic acid (AsA) and reduced glutathione (GSH)32. Therefore, the enhanced root hydraulic conductance and water uptake in response to Si could arise from a reduction in membrane oxidative damage32. In addition, Si-mediated transcriptional upregulation of root aquaporin genes contributed to increased hydraulic conductance and water uptake under drought stress31. It has been reported that oxidative damage causes plasma membrane dysfunction; thus, the overproduction of ROS under drought stress may negatively regulate the activities of plasma membrane aquaporins32. The role of aquaporins in root water uptake regulated by Si under drought stress is discussed in the following sections.

Overall, the modification of root growth and hydraulic conductance in response to Si application enhances root water uptake under drought stress conditions. A Si-mediated reduction in membrane oxidative damage via increased antioxidant defense may contribute to enhanced root hydraulic conductance. Further studies are needed to investigate how Si regulates root development under drought stress conditions. Specifically, the complex interactions between membrane oxidative damage and ROS accumulation in root hydraulic conductance need to be determined.

Regulation of aquaporins (AQPs)

Aquaporins belong to the major intrinsic protein (MIP) family and regulate the transport of water and small solutes across membranes78,79,80,81,82, contributing to root water uptake, especially under drought stress conditions31,71,83,84. Water moves within the roots both radially from the root surface into xylem vessels and axially along the xylem85, while aquaporins mainly function in radial water movement in both the water uptake and transport. There are three main pathways for water flow in radial movement: the apoplastic, symplastic, and transcellular pathways85. The symplastic and transcellular pathways are collectively referred to as the cell-to-cell pathway86, which is mainly dependent on aquaporins87.

In the presence of Si, there is a dual role played by aquaporins under drought stress. On the one hand, Lsi1, a Si-permeable channel, belongs to a NOD26-like intrinsic protein (NIP) subfamily of aquaporins, which are involved in Si transport12,88,89. As Si accumulation in plants requires the dual action of both the influx and efflux transporters, the Si transporter Lsi1 has evolved a unique selective amino acid filter, which is one of the required features to regulate the influx of Si and the indispensable key for plants to absorb Si12,90. On the other hand, Si induces the expression of aquaporin genes to increase root water uptake73,91; for example, in sorghum plants, Si application markedly enhances aquaporin activity via the upregulation of the SbPIP1;6, SbPIP2;2, and SbPIP2;6 genes, consequently increasing root water uptake by enhancing root hydraulic conductance under drought stress31,91,92. However, inconsistent results were observed in a Si excluder (tomato), and the expression of the SlPIP1;3, SlPIP1;5, and SlPIP2;6 genes was not significantly affected after Si application under drought stress32, suggesting that Si did not improve root water uptake by upregulating aquaporin genes in tomato roots but instead did so by increasing root hydraulic conductance (as mentioned above).

Therefore, the ability of Si to alleviate drought stress is mainly attributed to its direct effect through regulating the activity of aquaporins and gene expression, as well as its indirect effect through increasing root hydraulic conductance (personal communication with Rony Wallach, Hebrew University of Jerusalem). However, the molecular mechanism of Si-mediated alleviation of drought stress is poorly understood, and the genes related to water uptake and osmotic adjustment regulated by Si need to be determined. Further studies should focus on the underlying interactions between the Si and processes related to water relations (water uptake, transport, and loss) under stress conditions.

Enhancing mineral nutrient uptake and maintaining nutrient balance

Mineral nutrient uptake and homeostasis can be disrupted by environmental stimuli, especially drought stresses34,48. It has been reported that the uptake of nitrogen (N), phosphate (P), potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), copper (Cu), and manganese (Mn) increases in response to Si application under drought stress30,34,48,93, which not only enhances plant growth but also improves plant resistance and/or tolerance. For example, K and Ca contents were considerably increased in maize in response to Si application under drought stress30, in which K benefits plant growth, osmotic adjustment, and drought tolerance94, and Ca is critical for achieving better survival with improved plant growth95, maintaining the integrity of plant membranes and regulating ion permeability and selectivity96.

The possible mechanisms for Si-induced mineral nutrient uptake include (i) increasing water uptake and transpirational driving forces31,92, thus enhancing mineral nutrient movement from soil into roots; (ii) enhancing ion mobilization in roots (e.g., Si alleviates Fe deficiency in cucumber by increasing the apoplastic Fe pool in the roots and enhancing Fe mobilization in the roots due to Si-mediated biosynthesis of Fe-chelating compounds)97; (iii) stimulating membrane H + -ATPase activity driving mineral nutrient uptake (e.g., Si increased K + uptake in barley under osmotic stress by activating H + -ATPase in the membranes)98; (iv) regulating ion transporter genes (e.g., Si modulates the activities and gene expression of enzymes involved in Fe acquisition in cucumber)97, while Si also regulates genes involved in Mn and Cd uptake and translocation in rice99,100; and (v) enhancing the translocation of metabolites that contribute to root/shoot ion transport (e.g., Si increases micronutrient transport and distribution by increasing the content of long-distance molecules, such as citrate)101. In brief, the uptake of essential nutrients in response to Si application under drought stress maintains the nutrient balance, thereby increasing water uptake and improving plant resistance to environmental stress.

In summary, the beneficial effects of Si on water uptake may be attributed to the improvement in root growth, driving force, root hydraulic conductance, aquaporin activity, and gene expression, as well as the maintenance of nutrient balance (Fig. 2). The interactions between the Si and other essential nutrients under drought stress are worthy of further study to explore the role of Si in root water uptake.

Fig. 2: Water uptake increases in response to Si application under drought stress conditions.
figure 2

a Silicon (Si) application acts via the following mechanisms: (1) increasing the root/shoot ratio; (2) inducing root endodermal silicification and suberization; (3) enhancing the root driving force; (4) improving root hydraulic conductance (Lp); (5) increasing aquaporin (AQP) activity; and (6) maintaining nutrient balance. b Root hydraulic conductance and aquaporins are regulated by Si under drought stress. Si application improves root Lp by inhibiting reactive oxygen species (ROS) and hydrogen peroxide (H2O2) production and increases AQP activity by reducing ROS production and membrane damage, thus improving water uptake

Si regulates leaf water loss under drought stress

Numerous researchers have shown that Si application regulates gas exchange, which in turn contributes to drought tolerance, in species such as maize93,102, soybean103, cucumber104, and alfalfa105; this ultimately resulted in increased water-use efficiency (WUE) and the alleviation of drought stress93. In previous studies, Si-induced reduction in transpiration was considered to be the result of physical blockade of cuticular transpiration via cuticle layer thickening from silica deposits106,107,108, which contributes to the maintenance of leaf water potential underwater-deficient conditions54. For example, wheat leaves are thicker after Si application under drought, thus reducing transpirational water loss109,110. However, in maize plants, it was suggested that the lower transpiration of Si-supplied plants was primarily due to stomatal pores rather than the cuticular layer93,102, mainly attributed to the loss of guard cell turgor and changes in the physical and mechanical properties of the cell walls111,112,113.

In contrast to the abovementioned observations, some reports have suggested that Si application increased the leaf transpiration rate in rice, tomato, pepper, mangrove, and sorghum under drought stress31,32,48,114,115. This increased transpiration was attributed to an improvement in leaf water status via increased water uptake, enhanced leaf xylem sap flow, and increased leaf water potential resulting from a larger leaf area110. Such results were also consistent with those of Zhang et al.116, who suggested that Si-improved plant growth may be attributed to increased gas exchange parameters, e.g., transpiration and stomatal conductance. However, it has also been reported that Si has no effect on the transpiration rates of cucumber and rose plants under drought stress conditions117,118, implying that Si-regulated transpiration is dynamic and depends on root water status, environmental conditions, plant species, and genotype.

The role of Si in alleviating drought stress by regulating transpiration is summarized in Fig. 3. When root water uptake was limited, this model suggested that the Si supply decreased leaf transpiration to reduce water loss by physically blocking cuticular transpiration or stomatal movement. In contrast, Si increased leaf xylem sap flow and transpiration rates under drought stress, corresponding to increased photosynthesis rates. The differential impact of Si on transpiration rates may be related to the degree of stress. Under mild stress conditions, Si could increase root water uptake, corresponding to increased transpiration rates, and consequently increase plant growth under drought stress. When root water uptake is limited under heavy stress, plant leaves close their stomata to reduce water loss, which occurs most likely through a systemic signaling event(s). More broadly, leaf transpiration exerts feedback effects on root water transport models71. With high leaf transpiration rates, the transpiration force driving water across the roots mainly depends on the hydrostatic pressure difference between the root medium and xylem, which allows both the apoplastic and cell-to-cell pathways to be used. When transpiration is reduced, only a cell-to-cell process is available, which has high hydraulic resistance71. Nonetheless, detailed studies are still needed to understand the mechanisms of Si in whole-plant water relations and to consider the complex relationship between Si supply and transpiration in plants under drought.

Fig. 3: Si influences leaf transpiration under drought stress.
figure 3

a Leaf transpiration can be reduced by Si application under drought stress via (1) physical blockade of cuticular transpiration via cuticle layer thickening caused by silica deposits and via (2) regulation of stomatal movement by turgor loss of guard cells and by changes in the physical and mechanical properties of cell walls. b In contrast, Si application increased the leaf water potential (3) and water uptake (4), thus enhancing leaf xylem sap flow and transpiration under drought stress conditions. In addition, Si has also been reported to have no effect on leaf transpiration in some cases

Si invokes plant defense responses under drought stress

Modification of signaling pathways

To alleviate environmental stress, plants have developed a complex signal transduction network. Si application has been reported to increase plant tolerance by regulating endogenous plant phytohormone balance and associated signaling events, including those involving abscisic acid (ABA), JA, salicylic acid (SA), and ET22,53,119,120,121. For example, Si addition enhanced the drought tolerance of sorghum, at least in part, by regulating the synthesis of PAs, as well as ACC, the precursor of ET53. Furthermore, Si decreased JA contents in soybean under drought122, which suggested Si inhibited an early signaling event required for JA production. ABA, a stress-responsive hormone, plays an essential role in stomatal closure when plants are exposed to various environmental stresses123. In barley plants, Si application did not affect ABA levels in the leaves under normal conditions but decreased ABA homeostasis via transcriptional regulation of ABA biosynthesis and degradation pathways, thus improving stress tolerance124.

Several studies have proposed that Si mediates the modulation of multiple genes involved in stress-responsive pathways via the JA, ABA, and phenylpropanoid pathways125,126,127,128. In rice, Si regulates the transcription factors OsNAC5 and OsDREB2A, which trigger the expression of stress-responsive genes that impart tolerance to osmotic stress via ABA-dependent and ABA-independent pathways, respectively129,130. The Si-dependent upregulation of transcription factors could interact with cis-elements located in the promoter regions of genes involved in the stress response and trigger tolerance to abiotic and biotic stresses126. Given the current knowledge of these phytohormone signaling pathways, the means through which Si impacts particular components and affects crosstalk between signals under stress conditions must be urgently addressed.

Activation of the antioxidant system

The balance between ROS and antioxidants is disrupted by environmental stresses, resulting in oxidative damage to membrane lipids131,132. The antioxidative processes that reduce ROS in plant cells include both the enzymes [e.g., SOD, CAT, peroxidase (POD) and ascorbate peroxidase (APX)] and nonenzymatic compounds [e.g., AsA, GSH, tocopherols, and carotenoids]29,41. ROS accumulation under drought stress is inversely correlated with the activities of plasma membrane aquaporins76. Indeed, aquaporin phosphorylation status and intracellular trafficking are regulated by ROS-dependent signaling mechanisms133. Therefore, the regulation of water movement by Si is directly affected by the ROS-mediated process.

Si application enhances the resistance and tolerance of plants under drought stress by increasing plant defense responses, such as those of the antioxidant system, thereby reducing drought-induced oxidative stress70,111. In particular, Si increased the activities of SOD, CAT, and APX in wheat29, tomato41, chickpea70, rapeseed, and sunflower34, which in turn induced H2O2 production and lipid peroxidation underwater-deficient conditions. However, Si application decreased CAT, POD, and SOD activities and electrolyte leakage in soybean plants under drought stress35, indicating that oxidative damage induced by drought was alleviated by Si. Nevertheless, in drought-stressed wheat leaves, Si addition increased SOD activity while decreasing H2O2 and malondialdehyde (MDA) levels and electrolyte leakage29,134,135, suggesting that the different responses of enzyme activities to drought stress might be attributed to differences in plant species, growth stage, and stress degree. An essential role in alleviating oxidative damage in plants is also played by nonenzymatic antioxidants, and Si application increased GSH and AsA contents in drought-stressed wheat29,134. Moreover, activities of nonenzymatic antioxidants (e.g., AsA) in chickpea were induced by Si under drought stress conditions70, indicating that oxidative damage induced by drought was mitigated by Si by enhancing the activity of antioxidative systems. AsA reacts nonenzymatically with superoxide, H2O2, and singlet oxygen and reacts indirectly by regenerating tocopherols or synthesizing zeaxanthin in the xanthophyll cycle, which influences several enzyme activities and reduces the damage caused by the oxidative process through synergistic functions with those of other antioxidants136. The mechanisms by which Si activates antioxidant systems under drought stress are largely unknown; but it has been suggested that Si is involved in regulating the expression of genes related to the production and activation of antioxidant enzymes, such as TaSOD, TaCAT, and TaAPX137 under stress conditions. Moreover, exogenous application of Si alleviates drought stress through transcriptional regulation of enzymes involved in the ascorbate-glutathione (ASC–GSH) cycle (e.g., GS, GR, MDHAR, and DHAR) and in flavonoid secondary metabolism (e.g., PAL, CHS, F3H, DFR, and ANS)137.

To date, it has been found that Si can alleviate oxidative damage under drought stress by modulating plant antioxidant defense systems based on enzymatic or nonenzymatic constituents, which contributes to increased plant growth and whole-plant water balance. However, the importance of Si-mediated antioxidant defense largely depends upon plant species, cultivar, and growth stage, as well as the degree of stress and growth conditions. The underlying mechanisms by which Si alleviates oxidative damage under drought still need to be investigated, especially the role of Si in regulating the balance between ROS accumulation and antioxidant production.

Conclusion and implications

Drought stress is one of the major environmental factors that limits plant growth and crop productivity; this review summarizes the effects of Si on plant resistance and tolerance to drought stress (Table 1). Si application alleviates plant drought stress by (i) enhancing root water uptake, mainly through improving root growth, osmotic driving forces, hydraulic conductance, and mineral nutrient uptake, as well as by regulating aquaporin (AQP) activity and gene expression, (ii) regulating leaf transpirational water loss depending on root water status, and (iii) inducing plant defense responses through modification of signaling pathways and activation of antioxidant systems (Fig. 4). This makes Si application an attractive approach to improving plant water status and maintaining plant water balance under drought stress conditions. Understanding the interactions between Si application and plant responses will contribute to more efficient fertilization practices or enhanced stress tolerance of crop plants.

Table 1 Morphoanatomical, physiological, biochemical, and molecular processes involved in Si alleviation of drought stress in plants
Fig. 4: Key mechanisms involved in Si-triggered drought stress in plants.
figure 4

Plant water relations regulated by Si under drought stress conditions include (1) activation of antioxidant systems, (2) stimulation of gene expression and defense responses, (3) adjustment of osmotic processes and maintenance of homeostasis, (4) increases in nutrient uptake and maintenance of mineral balance, (5) regulation of photosynthesis and gas exchange, and (6) improvements in plant growth and water uptake

Based on the current knowledge, the distribution of Si and its functions under stress conditions need further investigation, especially the differences among Si accumulators, intermediates, and excluders and the strategies for alleviating drought stress. In addition, published works are inconsistent, which may reflect the absence of a “one-size-fits-all” model for Si effects, with differences in mechanisms depending on species, genotypes, and the environment. This needs to be recognized before Si can be successfully applied to agriculture. Therefore, a systematic assessment of Si effects is needed, in which the effects could be linked to, for example, specific quantitative trait loci (QTLs) and/or transcriptomic assessments. In addition, to overcome global environmental changes and improve crop production, the application method of Si (e.g., soil-based or foliar) and its effect on plant tolerance and/or resistance under field conditions still need to be extensively investigated.

References

  1. Epstein, E. Silicon. Annu. Rev. Plant Physiol. 50, 641–664 (1999).

    CAS  Google Scholar 

  2. Epstein, E. The anomaly of silicon in plant biology. P. Natl Acad. Sci. USA 91, 11–17 (1994).

    CAS  Google Scholar 

  3. Savant, N. K., Snyder, G. H. & Datnoff, L. E. Silicon management and sustainable rice production. Adv. Agron. 58, 151–199 (1997).

    CAS  Google Scholar 

  4. Ma, J. F. & Yamaji, N. Silicon uptake and accumulation in higher plants. Trends Plant Sci. 11, 392–397 (2006).

    PubMed  CAS  Google Scholar 

  5. Coskun, D., Britto, D. T., Huynh, W. Q. & Kronzucker, H. J. The role of silicon in higher plants under salinity and drought stress. Front. Plant Sci. 7, 1072 (2016).

    PubMed  PubMed Central  Google Scholar 

  6. Cooke, J., DeGabriel, J. L. & Hartley, S. E. The functional ecology of plant silicon: geoscience to genes. Funct. Ecol. 30, 1270–1276 (2016).

    Google Scholar 

  7. Coskun, D. et al. The controversies of silicon’s role in plant biology. N. Phytol. 221, 67–85 (2019).

    Google Scholar 

  8. Luyckx, M., Hausman, J., Lutts, S. & Guerriero, G. Silicon and plants: current knowledge and technological perspectives. Front. Plant Sci. 8, 411 (2017).

    PubMed  PubMed Central  Google Scholar 

  9. Liang, Y. et al. Importance of plant species and external silicon concentration to active silicon uptake and transport. N. Phytol. 172, 63–72 (2006).

    CAS  Google Scholar 

  10. Takahashi, E., Ma, J. F. & Miyake, Y. The possibility of silicon as an essential element for higher plants. J. Agric. Food Chem. 2, 99–102 (1990).

    CAS  Google Scholar 

  11. Richmond, K. E. & Sussman, M. Got silicon? The non-essential beneficial plant nutrient. Curr. Opi. Plant Biol. 6, 268–272 (2003).

    CAS  Google Scholar 

  12. Ma, J. F. & Yamaji, N. A cooperative system of silicon transport in plants. Trends Plant Sci. 20, 435–442 (2015).

    PubMed  CAS  Google Scholar 

  13. Yamaji, N., Mitatni, N. & Ma, J. F. A transporter regulating silicon distribution in rice shoots. Plant Cell 20, 1381–1389 (2008).

    PubMed  PubMed Central  CAS  Google Scholar 

  14. de Oliveira, R. L. L., de Mello Prado, R., Felisberto, G. & Cruz, F. J. R. Different sources of silicon by foliar spraying on the growth and gas exchange in sorghum. J. Soil Sci. Plant Nut. 19, 948–953 (2019).

    Google Scholar 

  15. de Souza Junior, J. P. et al. Effect of different foliar silicon sources on cotton plants. J. Soil Sci. Plant Nut. 21, 95–103 (2021).

    Google Scholar 

  16. Flores, R. A. et al. Nutrition and production of Helianthus annuus in a function of application of leaf silicon. J. Plant Nutr. 42, 137–144 (2019).

    CAS  Google Scholar 

  17. Hussain, S. et al. Foliar application of silicon improves stem strength under low light stress by regulating lignin biosynthesis genes in soybean (Glycine max (L.) Merr.). J. Hazard. Mater. 401, 123256 (2021).

    PubMed  CAS  Google Scholar 

  18. Puppe, D. & Sommer, M. Experiments, uptake mechanisms, and functioning of silicon foliar fertilization-a review focusing on maize, rice, and wheat. Adv. Agron. 152, 1–49 (2018).

    Google Scholar 

  19. Morato de Moraes, D. H. et al. Combined effects of induced water deficit and foliar application of silicon on the gas exchange of tomatoes for processing. Agron. 10, 1715 (2020).

    Google Scholar 

  20. Pilon, C., Soratto, R. P., Broetto, F. & Fernandes, A. M. Foliar or soil applications of silicon alleviate water-deficit stress of potato plants. Agron. J. 106, 2325–2334 (2014).

    CAS  Google Scholar 

  21. Cooke, J., Leishman, M. R. & Hartley, S. Consistent alleviation of abiotic stress with silicon addition: a meta-analysis. Funct. Ecol. 30, 1340–1357 (2016).

    Google Scholar 

  22. Wang, M. et al. Role of Silicon on Plant-Pathogen Interactions. Front. Plant Sci. 8, 701 (2017).

    PubMed  PubMed Central  Google Scholar 

  23. Meharg, C. & Meharg, A. A. Silicon, the silver bullet for mitigating biotic and abiotic stress, and improving grain quality, in rice? Environ. Exp. Bot. 120, 8–17 (2015).

    CAS  Google Scholar 

  24. Debona, D., Rodrigues, F. A. & Datnoff, L. E. Silicon’s role in abiotic and biotic plant stresses. Annu. Rev. Phytopathol. 55, 85–107 (2017).

    PubMed  CAS  Google Scholar 

  25. Thorne, S. J., Hartley, S. E. & Maathuis, F. J. M. Is silicon a panacea for alleviating drought and salt stress in crops? Front. Plant Sci. 11, 1221 (2020).

    PubMed  PubMed Central  Google Scholar 

  26. Vandegeer, R. K. et al. Leaf silicification provides herbivore defence regardless of the extensive impacts of water stress. Funct. Ecol. 35, 1200–1211 (2021).

    Google Scholar 

  27. Schwalm, C. R. et al. Global patterns of drought recovery. Nature 548, 202 (2017).

    PubMed  CAS  Google Scholar 

  28. Ming, D. F., Pei, Z. F., Naeem, M. S., Gong, H. J. & Zhou, W. J. Silicon alleviates PEG-induced water-deficit stress in upland rice seedlings by enhancing osmotic adjustment. J. Agron. Crop Sci. 198, 14–26 (2012).

    CAS  Google Scholar 

  29. Gong, H., Zhu, X., Chen, K., Wang, S. & Zhang, C. Silicon alleviates oxidative damage of wheat plants in pots under drought. Plant Sci. 169, 313–321 (2005).

    CAS  Google Scholar 

  30. Kaya, C., Tuna, L. & Higgs, D. Effect of silicon on plant growth and mineral nutrition of maize grown under water-stress conditions. J. Plant Nutr. 29, 1469–1480 (2006).

    CAS  Google Scholar 

  31. Liu, P. et al. Aquaporin-mediated increase in root hydraulic conductance is involved in silicon-induced improved root water uptake under osmotic stress in Sorghum bicolor L. J. Exp. Bot. 65, 4747–4756 (2014).

    PubMed  PubMed Central  CAS  Google Scholar 

  32. Shi, Y. et al. Silicon enhances water stress tolerance by improving root hydraulic conductance in Solanum lycopersicum L. Front. Plant Sci. 7, 196 (2016).

    PubMed  PubMed Central  Google Scholar 

  33. Ma, J. F. Role of silicon in enhancing the resistance of plants to biotic and abiotic stresses. Soil Sci. Plant Nutr. 50, 11–18 (2004).

    CAS  Google Scholar 

  34. Gunes, A., Pilbeam, D. J., Inal, A. & Coban, S. Influence of silicon on sunflower cultivars under drought stress, I: Growth, antioxidant mechanisms, and lipid peroxidation. Commun. Soil Sci. Plant Anal. 39, 1885–1903 (2008).

    CAS  Google Scholar 

  35. Shen, X. et al. Silicon effects on photosynthesis and antioxidant parameters of soybean seedlings under drought and ultraviolet-B radiation. J. Plant Physiol. 167, 1248–1252 (2010).

    PubMed  CAS  Google Scholar 

  36. Farooq, M. A. et al. Alleviation of cadmium toxicity by silicon is related to elevated photosynthesis, antioxidant enzymes; suppressed cadmium uptake and oxidative stress in cotton. Ecotox. Environ. Safe. 96, 242–249 (2013).

    CAS  Google Scholar 

  37. Helaly, M. N., El-Hoseiny, H., El-Sheery, N. I., Rastogi, A. & Kalaji, H. M. Regulation and physiological role of silicon in alleviating drought stress of mango. Plant Physiol. Biochem. 118, 31–44 (2017).

    PubMed  CAS  Google Scholar 

  38. Habibi, G. Silicon supplementation improves drought tolerance in canola plants. Russ. J. Plant Physiol. 61, 784–791 (2014).

    CAS  Google Scholar 

  39. Thorne, S. J., Hartley, S. E. & Maathuis, F. J. M. The effect of silicon on osmotic and drought stress tolerance in wheat landraces. Plants 10, 814 (2021).

    PubMed  PubMed Central  CAS  Google Scholar 

  40. Katz, O. Beyond grasses: the potential benefits of studying silicon accumulation in non-grass species. Front. Plant Sci. 5, 376 (2014).

    PubMed  PubMed Central  Google Scholar 

  41. Shi, Y. et al. Silicon improves seed germination and alleviates oxidative stress of bud seedlings in tomato under water deficit stress. Plant Physiol. Biochem. 78, 27–36 (2014).

    PubMed  CAS  Google Scholar 

  42. Ghareeb, H. et al. Transcriptome of silicon-induced resistance against Ralstonia solanacearum in the silicon non-accumulator tomato implicates priming effect. Physiol. Mol. Plant P. 75, 83–89 (2011).

    CAS  Google Scholar 

  43. Hodson, M. J., White, P. J., Mead, A. & Broadley, M. R. Phylogenetic variation in the silicon composition of plants. Ann. Bot. -Lond. 96, 1027–1046 (2005).

    CAS  Google Scholar 

  44. Hameed, A., Sheikh, M. A., Jamil, A. & Basra, S. M. A. Seed priming with sodium silicate enhances seed germination and seedling growth in wheat (Triticum aestivum L.) under water deficit stress induced by polyethylene glycol. Pak. J. Life Soc. Sci. 11, 19–24 (2013).

    Google Scholar 

  45. Zargar, S. M. & Agnihotri, A. Impact of silicon on various agro-morphological and physiological parameters in maize and revealing its role in enhancing water stress tolerance. Emir. J. Food Agr. 25, 138–141 (2013).

    Google Scholar 

  46. Biju, S., Fuentes, S. & Gupta, D. Silicon improves seed germination and alleviates drought stress in lentil crops by regulating osmolytes, hydrolytic enzymes and antioxidant defense system. Plant Physiol. Biochem. 119, 250–264 (2017).

    PubMed  CAS  Google Scholar 

  47. Zia, Z. et al. Effect of water management and silicon on germination, growth, phosphorus and arsenic uptake in rice. Ecotox. Environ. Safe. 144, 11–18 (2017).

    CAS  Google Scholar 

  48. Chen, W., Yao, X., Cai, K. & Chen, J. Silicon alleviates drought stress of rice plants by improving plant water status, photosynthesis and mineral nutrient absorption. Biol. Trace Elem. Res. 142, 67–76 (2011).

    PubMed  CAS  Google Scholar 

  49. Hattori, T. et al. Silicon-induced changes in viscoelastic properties of sorghum root cell walls. Plant Cell Physiol. 44, 743–749 (2003).

    PubMed  CAS  Google Scholar 

  50. Emam, M. M., Khattab, H. E., Helal, N. M. & Deraz, A. E. Effect of selenium and silicon on yield quality of rice plant grown under drought stress. Aust. J. Crop Sci. 8, 596–605 (2014).

    Google Scholar 

  51. Javot, H. & Maurel, C. The role of aquaporins in root water uptake. Ann. Bot. -Lond. 90, 301–313 (2002).

    CAS  Google Scholar 

  52. Hattori, T. et al. Silicon application by sorghum through the alleviation of stress-induced increase in hydraulic resistance. J. Plant Nutr. 31, 1482–1495 (2008).

    CAS  Google Scholar 

  53. Yin, L. et al. Silicon-mediated changes in polyamine and 1-aminocyclopropane-1-carboxylic acid are involved in silicon-induced drought resistance in Sorghum bicolor L. Plant Physiol. Biochem. 80, 268–277 (2014).

    PubMed  CAS  Google Scholar 

  54. Lux, A., Luxová, M., Hattori, T., Inanaga, S. & Sugimoto, Y. Silicification in sorghum (Sorghum bicolor) cultivars with different drought tolerance. Physiol. Plant. 115, 87–92 (2002).

    PubMed  CAS  Google Scholar 

  55. Fleck, A. T. et al. Silicon enhances suberization and lignification in roots of rice (Oryza sativa). J. Exp. Bot. 62, 2001–2011 (2010).

    PubMed  PubMed Central  Google Scholar 

  56. Fleck, A. T. et al. Silicon promotes exodermal casparian band formation in si-accumulating and si-excluding species by forming phenol complexes. PLoS ONE 10, e0138555 (2015).

    PubMed  PubMed Central  Google Scholar 

  57. Lux, A. et al. Silicification of root tissues. Plants 9, 111 (2020).

    PubMed Central  CAS  Google Scholar 

  58. Soukup, M. et al. Formation of silica aggregates in sorghum root endodermis is predetermined by cell wall architecture and development. Ann. Bot. -Lond. 120, 739–753 (2017).

    CAS  Google Scholar 

  59. Sonobe, K. et al. Diurnal variations in photosynthesis, stomatal conductance and leaf water relation in sorghum grown with or without silicon under water stress. J. Plant Nutr. 32, 433–442 (2009).

    CAS  Google Scholar 

  60. Sharp, R. E., Silk, W. K. & Hsiao, T. C. Growth of the maize primary root at low water potentials: I. Spatial distribution of expansive growth. Plant Physiol. 87, 50–57 (1988).

    PubMed  PubMed Central  CAS  Google Scholar 

  61. Blum, A. Osmotic adjustment is a prime drought stress adaptive engine in support of plant production. Plant Cell Environ. 40, 4–10 (2017).

    PubMed  CAS  Google Scholar 

  62. Morgan, J. M. Osmoregulation and water stress in higher plants. Annu. Rev. Plant Physiol. 35, 299–319 (1984).

    Google Scholar 

  63. Hare, P. & Cress, W. Metabolic implications of stress-induced proline accumulation in plants. Plant Growth Regul. 21, 79–102 (1997).

    CAS  Google Scholar 

  64. Ashraf, M. & Foolad, M. Roles of glycine betaine and proline in improving plant abiotic stress resistance. Environ. Exp. Bot. 59, 206–216 (2007).

    CAS  Google Scholar 

  65. Hsiao, T. C. & Xu, L. K. Sensitivity of growth of roots versus leaves to water stress: biophysical analysis and relation to water transport. J. Exp. Bot. 51, 1595–1616 (2000).

    PubMed  CAS  Google Scholar 

  66. Sonobe, K. et al. Effect of silicon application on sorghum root responses to water stress. J. Plant Nutr. 34, 71–82 (2010).

    Google Scholar 

  67. Crusciol, C. A., Pulz, A. L., Lemos, L. B., Soratto, R. P. & Lima, G. P. Effects of silicon and drought stress on tuber yield and leaf biochemical characteristics in potato. Crop Sci. 49, 949–954 (2009).

    CAS  Google Scholar 

  68. Zhu, Y. et al. The regulatory role of silicon on carbohydrate metabolism in Cucumis sativus L. under salt stress. Plant Soil 406, 231–249 (2016).

    CAS  Google Scholar 

  69. Zhu, Z., Wei, G., Li, J., Qian, Q. & Yu, J. Silicon alleviates salt stress and increases antioxidant enzymes activity in leaves of salt-stressed cucumber (Cucumis sativus L.). Plant Sci. 167, 527–533 (2004).

    CAS  Google Scholar 

  70. Gunes, A., Pilbeam, D. J., Inal, A., Bagci, E. G. & Coban, S. Influence of silicon on antioxidant mechanisms and lipid peroxidation in chickpea (Cicer arietinum L.) cultivars under drought stress. J. Plant Interact. 2, 105–113 (2007).

    CAS  Google Scholar 

  71. Steudle, E. Water uptake by roots: effects of water deficit. J. Exp. Bot. 51, 1531–1542 (2000).

    PubMed  CAS  Google Scholar 

  72. Wang, S. et al. Silicon enhanced salt tolerance by improving the root water uptake and decreasing the ion toxicity in cucumber. Front. Plant Sci. 6, 759 (2015).

    PubMed  PubMed Central  Google Scholar 

  73. Zhu, Y. X. et al. Silicon improves salt tolerance by increasing root water uptake in Cucumis sativus L. Plant Cell Rep. 34, 1629–1646 (2015).

    PubMed  CAS  Google Scholar 

  74. Hattori, T., Ishii, K., An, P. & Inanaga, S. Growth enhancement of rye by silicon application under two different soil water regimes. J. Plant Nutr. 32, 187–196 (2009).

    CAS  Google Scholar 

  75. Hattori, T. et al. Short term stomatal responses to light intensity changes and osmotic stress in sorghum seedlings raised with and without silicon. Environ. Exp. Bot. 60, 177–182 (2007).

    CAS  Google Scholar 

  76. Benabdellah, K., Ruiz-Lozano, J. M. & Aroca, R. Hydrogen peroxide effects on root hydraulic properties and plasma membrane aquaporin regulation in Phaseolus vulgaris. Plant Mol. Biol. 70, 647 (2009).

    PubMed  CAS  Google Scholar 

  77. Razem, F. A. & Bernards, M. A. Hydrogen peroxide is required for poly(phenolic) domain formation during wound-induced suberization. J. Agr. Food Chem. 50, 1009–1015 (2002).

    CAS  Google Scholar 

  78. Chrispeels, M. J. & Maurel, C. Aquaporins: the molecular basis of facilitated water movement through living plant cells? Plant Physiol. 105, 9 (1994).

    PubMed  PubMed Central  CAS  Google Scholar 

  79. Kruse, E., Uehlein, N. & Kaldenhoff, R. The aquaporins. Genome Biol. 7, 206 (2006).

    PubMed  PubMed Central  Google Scholar 

  80. Hove, R. M. & Bhave, M. Plant aquaporins with non-aqua functions: deciphering the signature sequences. Plant Mol. Biol. 75, 413–430 (2011).

    PubMed  CAS  Google Scholar 

  81. Wang, R. et al. Exploring the roles of aquaporins in plant–microbe interactions. Cells 7, 267 (2018).

    PubMed Central  CAS  Google Scholar 

  82. Wang, M. et al. The interactions of aquaporins and mineral nutrients in higher plants. Int. J. Mol. Sci. 17, 1229 (2016).

    PubMed Central  Google Scholar 

  83. Maurel, C., Verdoucq, L., Luu, D. T. & Santoni, V. Plant aquaporins: membrane channels with multiple integrated functions. Annu. Rev. Plant Biol. 59, 595–624 (2008).

    PubMed  CAS  Google Scholar 

  84. Kaldenhoff, R. et al. Aquaporins and plant water balance. Plant Cell Environ. 31, 658–666 (2008).

    PubMed  CAS  Google Scholar 

  85. Steudle, E. & Peterson, C. A. How does water get through roots? J. Exp. Bot. 49, 775–788 (1998).

    CAS  Google Scholar 

  86. Chaumont, F. & Tyerman, S. D. Aquaporins: highly regulated channels controlling plant water relations. Plant Physiol. 164, 1600–1618 (2014).

    PubMed  PubMed Central  CAS  Google Scholar 

  87. Vandeleur, R. K. et al. The role of plasma membrane intrinsic protein aquaporins in water transport through roots: diurnal and drought stress responses reveal different strategies between isohydric and anisohydric cultivars of grapevine. Plant Physiol. 149, 445–460 (2009).

    PubMed  PubMed Central  CAS  Google Scholar 

  88. Ma, J. F. et al. A silicon transporter in rice. Nature 440, 688 (2006).

    PubMed  CAS  Google Scholar 

  89. Chiba, Y., Mitani, N., Yamaji, N. & Ma, J. F. HvLsi1 is a silicon influx transporter in barley. Plant J. 57, 810–818 (2009).

    PubMed  CAS  Google Scholar 

  90. Deshmukh, R. & Belanger, R. R. Molecular evolution of aquaporins and silicon influx in plants. Funct. Ecol. 30, 1277–1285 (2016).

    Google Scholar 

  91. Liu, P. et al. Enhanced root hydraulic conductance by aquaporin regulation accounts for silicon alleviated salt-induced osmotic stress in Sorghum bicolor L. Environ. Exp. Bot. 111, 42–51 (2015).

    CAS  Google Scholar 

  92. Chen, D., Wang, S., Yin, L. & Deng, X. How does silicon mediate plant water uptake and loss under water deficiency? Front. Plant Sci. 9, 281 (2018).

    PubMed  PubMed Central  CAS  Google Scholar 

  93. Gao, X., Zou, C., Wang, L. & Zhang, F. Silicon improves water use efficiency in maize plants. J. Plant Nutr. 27, 1457–1470 (2005).

    Google Scholar 

  94. Ahmed, M., Qadeer, U. & Aslam, M. A. Silicon application and drought tolerance mechanism of sorghum. Afr. J. Agr. Res. 6, 594–607 (2011).

    Google Scholar 

  95. Cachorro, P., Ortiz, A. & Cerdá, A. Implications of calcium nutrition on the response of Phaseolus vulgaris L. to salinity. Plant Soil 159, 205–212 (1994).

    CAS  Google Scholar 

  96. Marschner, P. Marschner’s Mineral nutrition of higher plants. 3rd edn (Academic Press, 2012).

  97. Pavlovic, J. et al. Silicon alleviates iron deficiency in cucumber by promoting mobilization of iron in the root apoplast. N. Phytol. 198, 1096–1107 (2013).

    CAS  Google Scholar 

  98. Liang, Y. Effects of silicon on enzyme activity and sodium, potassium and calcium concentration in barley under salt stress. Plant Soil 209, 217 (1999).

    CAS  Google Scholar 

  99. Che, J., Yamaji, N., Shao, J. F., Ma, J. F. & Shen, R. F. Silicon decreases both uptake and root-to-shoot translocation of manganese in rice. J. Exp. Bot. 67, 1535–1544 (2016).

    PubMed  PubMed Central  CAS  Google Scholar 

  100. Shao, J. F., Che, J., Yamaji, N., Shen, R. F. & Ma, J. F. Silicon reduces cadmium accumulation by suppressing expression of transporter genes involved in cadmium uptake and translocation in rice. J. Exp. Bot. 68, 5641–5651 (2017).

    CAS  Google Scholar 

  101. Hernandez-Apaolaza, L. Can silicon partially alleviate micronutrient deficiency in plants? A review. Planta 240, 447–458 (2014).

    PubMed  CAS  Google Scholar 

  102. Gao, X., Zou, C., Wang, L. & Zhang, F. Silicon decreases transpiration rate and conductance from stomata of maize plants. J. Plant Nutr. 29, 1637–1647 (2006).

    CAS  Google Scholar 

  103. Küpfer, C. & Kahnt, G. Effects of the application of amorphous silica on transpiration and photosynthesis of soybean plants under varied soil and relative air humidity conditions. J. Agron. Crop Sci. 168, 318–325 (1992).

    Google Scholar 

  104. Ma, C. C., Li, Q. F., Gao, Y. B. & Xin, T. R. Effects of silicon application on drought resistance of cucumber plants. Soil Sci. Plant Nutr. 50, 623–632 (2004).

    Google Scholar 

  105. Liu, H. X. & Guo, Z. G. Forage Yield and water use efficiency of alfalfa applied with silicon under water deficit conditions. Philipp. Agric. Sci. 96, 370–376 (2013).

    Google Scholar 

  106. Agarie, S., Uchida, H., Agata, W., Kubota, F. & Kaufman, P. B. Effects of silicon on transpiration and leaf conductance in rice plants (Oryza sativa L.). Plant Prod. Sci. 1, 89–95 (1998).

    Google Scholar 

  107. Savant, N., Snyder, G. & Datnoff, L. Silicon management and sustainable rice production. Adv. Agron. 58, 151–199 (1996).

    Google Scholar 

  108. Savant, N. K., Korndörfer, G. H., Datnoff, L. E. & Snyder, G. H. Silicon nutrition and sugarcane production: a review. J. Plant Nutr. 22, 1853–1903 (1999).

    CAS  Google Scholar 

  109. Gong, H., Chen, K., Chen, G., Wang, S. & Zhang, C. Effects of silicon on growth of wheat under drought. J. Plant Nutr. 26, 1055–1063 (2003).

    CAS  Google Scholar 

  110. Hattori, T. et al. Application of silicon enhanced drought tolerance in Sorghum bicolor. Physiol. Plant. 123, 459–466 (2005).

    CAS  Google Scholar 

  111. Zhu, Y. & Gong, H. Beneficial effects of silicon on salt and drought tolerance in plants. Agron. Sustain. Dev. 34, 455–472 (2014).

    CAS  Google Scholar 

  112. Ueno, O. & Agarie, S. Silica deposition in cell walls of the stomatal apparatus of rice leaves. Plant Prod. Sci. 8, 71–73 (2005).

    Google Scholar 

  113. Savvas, D. & Ntatsi, G. Biostimulant activity of silicon in horticulture. Sci. Hortic. 196, 66–81 (2015).

    CAS  Google Scholar 

  114. Pereira, T. S. et al. Positive interference of silicon on water relations, nitrogen metabolism, and osmotic adjustment in two pepper (Capsicum annuum) cultivars under water deficit. Aust. J. Crop Sci. 7, 1064 (2013).

    Google Scholar 

  115. Zhang, Q. et al. Silicon alleviation of cadmium toxicity in mangrove (Avicennia marina) in relation to cadmium compartmentation. J. Plant Growth Regul. 33, 233–242 (2014).

    CAS  Google Scholar 

  116. Zhang, C. et al. Foliar application of Sili-K® increases chestnut (Castanea spp.) growth and photosynthesis, simultaneously increasing susceptibility to water deficit. Plant Soil 365, 211–225 (2013).

    CAS  Google Scholar 

  117. Hattori, T., Sonobe, K., Inanaga, S., An, P. & Morita, S. Effects of silicon on photosynthesis of young cucumber seedlings under osmotic stress. J. Plant Nutr. 31, 1046–1058 (2008).

    CAS  Google Scholar 

  118. Savvas, D. et al. Interactions between silicon and NaCl-salinity in a soilless culture of roses in greenhouse. Eur. J. Hortic. Sci. 72, 73 (2007).

    CAS  Google Scholar 

  119. Fauteux, F., Chain, F., Belzile, F., Menzies, J. G. & Bélanger, R. R. The protective role of silicon in the Arabidopsis–powdery mildew pathosystem. P. Natl Acad. Sci. USA 103, 17554–17559 (2006).

    CAS  Google Scholar 

  120. Brunings, A. et al. Differential gene expression of rice in response to silicon and rice blast fungus Magnaporthe oryzae. Ann. Appl. Biol. 155, 161–170 (2009).

    CAS  Google Scholar 

  121. Kim, Y. H. et al. Silicon application to rice root zone influenced the phytohormonal and antioxidant responses under salinity stress. J. Plant Growth Regul. 33, 137–149 (2014).

    CAS  Google Scholar 

  122. Hamayun, M. et al. Silicon alleviates the adverse effects of salinity and drought stress on growth and endogenous plant growth hormones of soybean (Glycine max L.). Pak. J. Bot. 42, 1713–1722 (2010).

    CAS  Google Scholar 

  123. Lee, S. C. & Luan, S. ABA signal transduction at the crossroad of biotic and abiotic stress responses. Plant Cell Environ. 35, 53–60 (2012).

    PubMed  CAS  Google Scholar 

  124. Hosseini, S. A. et al. Induction of barley silicon transporter HvLsi1 and HvLsi2, increased silicon concentration in the shoot and regulated starch and ABA homeostasis under osmotic stress and concomitant potassium deficiency. Front. Plant Sci. 8, 1359 (2017).

    PubMed  PubMed Central  Google Scholar 

  125. Kim, Y. H. et al. Regulation of jasmonic acid biosynthesis by silicon application during physical injury to Oryza sativa L. J. Plant Res. 127, 525–532 (2014).

    PubMed  CAS  Google Scholar 

  126. Manivannan, A. & Ahn, Y. K. Silicon regulates potential genes involved in major physiological processes in plants to combat stress. Front. Plant Sci. 8, 1346 (2017).

    PubMed  PubMed Central  Google Scholar 

  127. Shetty, R. et al. Silicon-induced changes in antifungal phenolic acids, flavonoids, and key phenylpropanoid pathway genes during the interaction between miniature roses and the biotrophic pathogen Podosphaera pannosa. Plant Physiol. 157, 2194–2205 (2011).

    PubMed  PubMed Central  CAS  Google Scholar 

  128. Song, A. et al. The role of silicon in enhancing resistance to bacterial blight of hydroponic- and soil-cultured rice. Sci. Rep. 6, 24640–24640 (2016).

    PubMed  PubMed Central  CAS  Google Scholar 

  129. Dubouzet, J. G. et al. OsDREB genes in rice, Oryza sativa L., encode transcription activators that function in drought-, high-salt- and cold-responsive gene expression. Plant J. 33, 751–763 (2003).

    PubMed  CAS  Google Scholar 

  130. Hussain, S. S., Kayani, M. A. & Amjad, M. Transcription factors as tools to engineer enhanced drought stress tolerance in plants. Biotechnol. Progr. 27, 297–306 (2011).

    CAS  Google Scholar 

  131. Egert, M. & Tevini, M. Influence of drought on some physiological parameters symptomatic for oxidative stress in leaves of chives (Allium schoenoprasum). Environ. Exp. Bot. 48, 43–49 (2002).

    CAS  Google Scholar 

  132. Smirnoff, N. The role of active oxygen in the response of plants to water deficit and desiccation. N. Phytol. 125, 27–58 (1993).

    CAS  Google Scholar 

  133. Boursiac, Y. et al. The response of Arabidopsis root water transport to a challenging environment implicates reactive oxygen species-and phosphorylation-dependent internalization of aquaporins. Plant Signal. Behav. 3, 1096–1098 (2008).

    PubMed  PubMed Central  Google Scholar 

  134. Pei, Z. F. et al. Silicon improves the tolerance to water-deficit stress induced by polyethylene glycol in wheat (Triticum aestivum L.) Seedlings. J. Plant Growth Regul. 29, 106–115 (2009).

    CAS  Google Scholar 

  135. Gong, H., Chen, K., Zhao, Z., Chen, G. & Zhou, W. Effects of silicon on defense of wheat against oxidative stress under drought at different developmental stages. Biol. Plant. 52, 592–596 (2008).

    CAS  Google Scholar 

  136. Ahmad, P., Jaleel, C. A., Salem, M. A., Nabi, G. & Sharma, S. Roles of enzymatic and nonenzymatic antioxidants in plants during abiotic stress. Crit. Rev. Biotechnol. 30, 161–175 (2010).

    PubMed  CAS  Google Scholar 

  137. Ma, D. et al. Silicon application alleviates drought stress in wheat through transcriptional regulation of multiple antioxidant defense pathways. J. Plant Growth Regul. 35, 1–10 (2016).

    CAS  Google Scholar 

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Acknowledgements

This work was financially supported by the National Key R&D Program (2016YFD0200900), the Fundamental Research Funds for the Central Universities (KYGD202007), the National Natural Science Foundation of China (32072673), and the Young Elite Scientists Sponsorship Program by CAST (2018QNRC001).

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Wang, M., Wang, R., Mur, L.A.J. et al. Functions of silicon in plant drought stress responses. Hortic Res 8, 254 (2021). https://doi.org/10.1038/s41438-021-00681-1

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