Societal Impact Statement Soil organic carbon (SOC) is vital for soil health, food security and climate change mitigation. We reviewed how silicon (Si) fertilisers, commonly used to improve plant health, may also influence SOC dynamics. We developed a framework linking Si and SOC and discussed the possibility of Si‐mediated plant changes contributing to SOC sequestration. We highlight that Si fertilisation is a potential strategy to reconcile the contradiction between intensive agriculture and the need to sequester carbon, supporting both productivity and decarbonisation goals. Summary The quantity and quality of plant C inputs to soil significantly influence decomposition and stabilisation processes which primarily affect the dynamics of soil organic carbon (SOC). Si has emerged as an important element for improving plant performance, which in turn affects the quantity and quality of such plant C inputs. Research on the interaction between Si and plant biochemical processes highlights a trade‐off between Si and C. Additionally, Si alters plant stoichiometry and belowground C allocation by promoting nitrogen (N) and phosphorus (P) use efficiency, potentially impacting C cycling in rhizosphere processes. However, these processes have not been thoroughly understood to date, limiting our understanding of the role of Si in soil C cycling. This review synthesises existing literature to advance the understanding of plant silicification in soil C cycling. For the first time, we propose a framework linking plant silicification and soil C cycling, via two pathways. First, Si affects C cycling during plant litter decomposition by altering plant chemical composition. We hypothesise that Si‐mediated changes in stoichiometry and C quality reduce litter stability and accelerate processing by the soil community, ultimately promoting SOC stabilisation. Second, Si‐enhanced plant nutritional status may alter belowground C allocation, impacting rhizosphere C cycling. We expect that plant silicification would reduce native rhizosphere SOC loss by the rhizosphere priming effect, as improved plant nutritional status results in less belowground C allocation for resource acquisition. We consider that Si fertilisation could contribute to maintaining soil health, particularly in agricultural systems.
Prior research finds that firms use both accrual-based earnings management (AEM) and real earnings management (REM) to manage financial reporting outcomes and that each practice influences firm performance. We extend this research by examining how managers' choices regarding the mix of AEM and REM relate to future performance. We argue that the sequential nature of the two earnings management strategies constrains managers' ability to obtain a mix of AEM and REM that minimizes the total cost of earnings management, leading to weaker future performance. Consistent with this argument, we find evidence of deviations from the mix of AEM that would be expected based only on their costs: (1) resulting in future earnings and cash flows that are lower than the firm's historical performance, and (2) being significantly negatively associated with future buy-and-hold abnormal returns. We find similar results using commonly used measures of earnings management and recently refined measures designed to capture opportunistic earnings manipulation. Our evidence indicates that deviations from the mix of AEM and REM expected based on their relative costs are costly to firms regardless of whether managers' intent is to inform or to mislead financial statement users.
The performance of herbivorous animals depends on the nutritional and defensive traits of the plants they consume. The uptake and deposition of biogenic silicon in plant tissues is arguably the most basic and ubiquitous anti-herbivore defence used by plants, especially grasses. We conducted meta-analyses of 150 studies reporting how vertebrate and invertebrate herbivores performed when feeding on silicon-rich plants relative to those feeding on low-silicon plants. Silicon levels were 52% higher and 32% more variable in silicon-rich plants compared to plants with low silicon, which resulted in an overall 33% decline in herbivore performance. Fluid-feeding herbivore performance was less adversely impacted (-14%) than tissue-chewing herbivores, including mammals (-45%), chewing arthropods (-33%) and plant-boring arthropods (-39%). Fluid-feeding arthropods with a wide diet breadth or those feeding on perennial plant species were mostly unaffected by silicon defences. Unlike many other plant defences, where diet specialisation often helps herbivores overcome their effects, silicon negatively impacts chewing herbivores regardless of diet breadth. We conclude that silicon defences primarily target chewing herbivores and impact vertebrate and invertebrate herbivores to a similar degree.
Silicon (Si) accumulation by grasses is a key mechanism for alleviating biotic and abiotic stresses, including insect herbivory. In addition to conferring physical resistance, tissue silicification may enhance anti-herbivore phytohormone production, such as the jasmonic and salicylic (JA and SA) acid pathways, and downstream regulation of defence genes, although this is poorly understood. Elevated atmospheric carbon dioxide (eCO2) concentrations predicted by climate models are reported to reduce Si accumulation in several plant taxa and may therefore compromise Si-augmented resistance. We investigated how Si enrichment and eCO2 regulate the JA and SA pathways and expression of defence genes in wheat (Triticum aestivum) challenged by a global insect pest (Helicoverpa armigera). Si treatments increased JA production and expression of beta-1,3-ENDOGLUCANASE (GNS), and MITOGEN-ACTIVATED PROTEIN KINASE (MAPK; WCK-1) defence genes, while suppressing SA production, resulting in reduced feeding and growth of H. armigera. In contrast, under eCO2 conditions, Si accumulation was reduced, GNS downregulated, but SA production was upregulated. Despite compromised plant defences, H. armigera growth rates were reduced under eCO2. We conclude that eCO2 and Si supplementation contrastingly regulate anti-herbivore defences in wheat; these important drivers operate independently and may influence future patterns of pest resistance in wheat under projected rises in atmospheric CO2.
AIMS:The objective of this research is to evaluate the cost-effectiveness of zuranolone, the first oral treatment indicated for postpartum depression (PPD) in adults approved by the United States Food and Drug Administration. METHODS:Zuranolone and selective serotonin reuptake inhibitor (SSRI) trial-based efficacy was derived from an indirect treatment comparison. Long-term efficacy outcomes were based on a large longitudinal cohort study. Maternal health utility values were derived from trial-based, short-form 6-D responses. Other inputs were derived from literature and economic data from the US Bureau of Labor Statistics. We estimated costs (2023 US dollars) and quality-adjusted life-years (QALYs) for patients with PPD treated with zuranolone (14-day dosing) or SSRIs (chronic dosing). The indirect costs and QALYs of the children and partners were also estimated. RESULTS:The incremental cost-effectiveness ratio for zuranolone versus SSRIs was $94,741 per QALY gained over an 11-year time horizon. Maternal total direct medical costs averaged $84,318 in the zuranolone arm, compared to $86,365 in the SSRI arm. Zuranolone-treated adults averaged 6.178 QALYs compared to 6.116 QALYs for the SSRI arm. Costs and utilities for the child and partner were also included in the base case. Drug and administration costs for zuranolone averaged $15,902, compared to $30 for SSRIs over the studied time horizon. Results were sensitive to the model time horizon. LIMITATIONS:As head-to-head trials were not available to permit direct comparison, efficacy inputs were derived from an indirect treatment comparison which can be confounded by cross-trial differences. The data used are reflective of a general PPD population rather than marginalized individuals who may be at a greater risk for adverse PPD outcomes. The model likely excludes unmeasured effects for patient, child, and partner. CONCLUSIONS:This economic model's results suggest that zuranolone is a more cost-effective therapy compared to SSRIs for treating adults with PPD.
Alcohol use disorder (AUD) is a significant risk factor for severe acute respiratory distress syndrome. We found that AUD causes a phenotypic shift in gene expression in human bronchial epithelial cells, enhancing expression of epidermal genes. AUD cells infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) had higher levels of proinflammatory cytokine secretion and barrier dysfunction not present in infected non-AUD cells, consistent with increased early COVID-19 severity due to AUD.
The uptake and accumulation of silicon (Si) in grass plants play a crucial role in alleviating both biotic and abiotic stresses. Si supplementation has been reported to increase activity of defence-related antioxidant enzyme, which helps to reduce oxidative stress caused by reactive oxygen species (ROS) following herbivore attack. Atmospheric CO2 levels are known to affect Si accumulation in grasses; reduced CO2 concentrations increase Si accumulation whereas elevated CO2 concentrations often decrease Si accumulation. This can potentially affect antioxidant enzyme activity and subsequently insect herbivory, but this remains untested. We examined the effects of Si supplementation and herbivory by Helicoverpa armigera on antioxidant enzyme (catalase, CAT; superoxide dismutase, SOD; and ascorbate peroxidase, APX) activity in tall fescue grass (Festuca arundinacea) grown under CO2 concentrations of 200, 410, and 640 ppm representing reduced, ambient, and elevated CO2 levels, respectively. We also quantified foliar Si, carbon (C), and nitrogen (N) concentrations and determined how changes in enzymes and elemental chemistry affected H. armigera relative growth rates and plant consumption. Rising CO2 concentrations increased plant mass and foliar C but decreased foliar N and Si. Si supplementation enhanced APX and SOD activity under the ranging CO2 regimes. Si accumulation and antioxidant enzyme activity were at their highest level under reduced CO2 conditions and their lowest level under future levels of CO2. The latter corresponded with increased herbivore growth rates and plant consumption, suggesting that some grasses could become more susceptible to herbivory under projected CO2 conditions.
Many temperate grasses are both hyper-accumulators of silicon (Si) and hosts of Epichloe fungal endophytes, functional traits which may alleviate environmental stresses such as herbivore attack. Si accumulation and endophyte infection may operate synergistically, but this has not been tested in a field setting, nor in the context of changing environmental conditions. Predicted increases in atmospheric CO2 concentrations can affect both Si accumulation and endophyte function, but these have not been studied in combination.We investigated how elevated atmospheric CO2 (eCO(2)), Si supplementation, endophyte-presence and insect herbivory impacted plant growth, stoichiometry (C, N, P and Si), leaf gas exchange (rates of photosynthesis, stomatal conductance, transpiration rates) and endophyte production of anti-herbivore defences (alkaloids) of an important pasture grass (tall fescue; Lolium arundinaceum) in the field.eCO(2) and Si supplementation increased shoot biomass (+52% and +31%, respectively), whereas herbivory reduced shoot biomass by at least 35% and induced Si accumulation by 24%. Shoot Si concentrations, in contrast, decreased by 17%-21% under eCO(2). Si supplementation and herbivory reduced shoot C concentrations. eCO(2) reduced shoot N concentrations which led to increased shoot C:N ratios. Overall, shoot P concentrations were 26% lower in endophytic plants compared to non-endophytic plants, potentially due to decreased mass flow (i.e. observed reductions in stomatal conductance and transpiration). Alkaloid production was not discernibly affected by any experimental treatment. The negative impacts of endophytes on P uptake were particularly strong under eCO(2).We show that eCO(2) and insect herbivory reduce and promote Si accumulation, respectively, incorporating some field conditions for the first time. This indicates that these drivers operate in a more realistic ecological context than previously demonstrated. Reduced uptake of P in endophytic plants may adversely affect plant productivity in the future, particularly if increased demand for P due to improved plant growth under eCO(2) cannot be met.
An academic journal is produced by a voluntary organization of scholars who create bodies of common knowledge consisting of the journal's published articles, along with all the references that link to the sources of knowledge for those articles. Even journals in the same discipline develop distinct bodies of common knowledge. New articles simultaneously build on and contribute to this common knowledge and we argue that this interaction with a journal's common knowledge influences how an article will be cited in the future. We explore the ecosystem identified by the Financial Times 50 management journals, demonstrating the overlap and distinction in their common knowledge. We find that journals fundamentally differ in the body of knowledge that comprises them, the sources of knowledge that contribute to them, and the journals to which they make an impact. Our findings generate novel insights into how the references cited in an article affect future citations.
Purpose Silicon (Si) accumulation in plant tissues plays a vital role in alleviating biotic and abiotic stresses, including drought. Temperate regions are predicted to experience reductions in the quantity and frequency of rainfall events, potentially impacting plant Si uptake via the transpiration stream. Despite the importance for predicting plant responses to Si amendments, the effects of changes in rainfall patterns on Si uptake in cereals have not been characterised. Methods Five watering regimes were applied based on predicted precipitation scenarios, varying the quantity of water delivered (ambient, 40% or 60% reduction) and watering frequency (40% reduction in quantity, applied 50% or 25% of ambient frequency), and the effects on growth and leaf Si concentrations of a barley landrace and cultivar were determined. Results Reductions in the quantity of water reduced plant growth and yield, whereas reducing the watering frequency had little impact on growth, and in some cases partially ameliorated the negative effects of drought. Reductions in quantity of water lowered leaf Si concentrations in both the cultivar and landrace, although this effect was alleviated under the drought/deluge watering regime. The landrace had greater leaf Si concentration than the cultivar regardless of watering regime, and under ambient watering deposited Si in all cells between trichomes, whereas the cultivar exhibited gaps in Si deposition. Conclusion The impact of future reductions in rainfall on barley productivity will depend upon how the water is delivered, with drought/deluge events likely to have smaller effects on yield and on Si uptake than continuous drought.
Although some view the hiring of interim executives as evidence of poor governance, this practice represents 15 to 20 percent of all chief financial officer (CFO) appointments. We examine the determinants and consequences of interim CFO successions. We find that smaller and poorer performing firms are more likely to appoint interim CFOs, as are firms with lower financial reporting quality and those faced with unexpected CFO departures. We also find that market participants respond negatively to interim CFO appointments. Although interim CFOs are associated with higher income-increasing earnings management and underinvestment, on average, interim CFO firms with strong corporate governance do not exhibit significant earnings management. Finally, permanent CFOs appointed following interim CFOs achieve greater profitability and are less likely to underinvest. Our study provides valuable insights for directors, management teams, auditors, investors, and researchers regarding the near- and long-term effects of appointing interim CFOs.
Predicting how plants allocate to different anti-herbivore defences in response to elevated carbon dioxide (CO2) concentrations is important for understanding future patterns of crop susceptibility to herbivory. Theories of defence allocation, especially in the context of environmental change, largely overlook the role of silicon (Si), despite it being the major anti-herbivore defence in the Poaceae. We demonstrated that elevated levels of atmospheric CO2 (e[CO2]) promoted plant growth by 33% and caused wheat (Triticum aestivum) to switch from Si (-19%) to phenolic (+44%) defences. Despite the lower levels of Si under e[CO2], resistance to the global pest Helicoverpa armigera persisted; relative growth rates (RGRs) were reduced by at least 33% on Si-supplied plants, irrespective of CO2 levels. RGR was negatively correlated with leaf Si concentrations. Mandible wear was c. 30% higher when feeding on Si-supplemented plants compared to those feeding on plants with no Si supply. We conclude that higher carbon availability under e[CO2] reduces silicification and causes wheat to increase concentrations of phenolics. However, Si supply, at all levels, suppressed the growth of H. armigera under both CO2 regimes, suggesting that shifts in defence allocation under future climate change may not compromise herbivore resistance in wheat.
Herbivorous insects have evolved various anti-predator defences, including morphological, behavioural, and immune defences, which can make biocontrol of herbivorous pests challenging. Silicon (Si) accumulation in plants is a potent physical defence against mandibulate insects. However, it remains uncertain how Si affects the anti-predator defences of insect herbivores and plant defences following herbivory. We grew the model grass, Brachypodium distachyon, hydroponically with (+Si) or without (–Si) Si and investigated the plant-mediated effects of Si on the anti-predator defences of the cotton bollworm, Helicoverpa armigera, integrating morphological (i.e. integument resistance and thickness), behavioural, and immune defences. We also examined the effects of Si on plant compensatory growth and leaf trichome production. Larval growth, leaf consumption, and integument resistance were lower when feeding on +Si plants compared to when feeding on –Si plants. Larval integument thickness, defensive behaviours, haemocyte density, and lysozyme-like activity in the haemolymph were unaffected by Si. Larvae fed on +Si plants had higher haemolymph phenoloxidase (PO) and total-PO activities than larvae fed on –Si plants, although this did not enhance the melanisation response of larvae. Furthermore, Si supplies increased plant compensation for herbivory and constitutive trichome production, whereas herbivory induced trichome production only on –Si plants. We provide the first evidence for plant-mediated effects of Si on anti-predator defences of an insect herbivore. We suggest that the lower integument resistance of larvae when feeding on Si-supplemented plants could contribute to their vulnerability to natural enemies and that high PO activity may impose fitness costs (e.g. delayed development).
1. Grasses have developed a wide range of morphological and physiological mechanisms to resist herbivory. For instance, they accumulate silicon (Si) in tissue, as physical defence, and associate symbiotically with foliar Epichloe-endophytes that provide chemical defence via antiherbivore alkaloids. Recent evidence showed that some Epichloe-endophytes increase foliar Si in forage grasses; however, whether this impacts insect herbivores is unknown. Furthermore, while Si is primarily a physical defence, it also affects production of plant defensive secondary metabolites; Si supply might therefore affect Epichloe-alkaloids, although this remains untested. 2. We grew endophyte-free (Nil) and Epichloe-infected tall fescue and perennial ryegrass in a factorial combination with or without Si supplementation, in the absence or presence of Helicoverpa armigera. Epichloe-endophyte strains were AR584 for tall fescue, and AR37, AR1 or Wild-type (WT) for perennial ryegrass. We assessed how Si supply and Epichloe-endophytes in interaction with herbivory affected foliar Si and mutualist-derived alkaloid concentrations. Subsequently, their effects on H. armigera relative growth rates (RGRs) were evaluated. 3. Endophytes generally increased Si concentrations in Si-supplied plants. In tall fescue AR584 and perennial ryegrass AR37, endophytes increased constitutive ( herbivore-free) and induced (herbivore-inoculated) Si concentrations by at least 25%; in contrast, in perennial ryegrass, the AR1 endophyte only increased constitutive levels. Si supply did not affect alkaloids produced by AR584 or AR1/WT endophytes; however, in the presence of herbivory, Si supply decreased the induction of alkaloids produced by AR37 endophytes by 33%. For tall fescue, Si supply reduced H. armigera RGR by at least 76%, regardless of endophytic status, whereas, endophyte-alkaloids played a secondary role only reducing herbivore growth in the absence of Si supply. Conversely, in perennial ryegrass, both Si and endophyte-alkaloids (regardless of Si supply) reduced herbivore RGR although not synergised. 4. Novel interactions between constitutive and induced Si-and alkaloid-based antiherbivore defences in grasses were observed. Overall, Si had a greater effect on the folivore than endophytes in both grasses. Endophyte defences contributed more to herbivore resistance in perennial ryegrass than tall fescue. We demonstrate that Si and endophytes were not antagonistic and highlight that the protective nature of their interaction varies with the grass-endophyte species tested.
Detrimental impacts of drought on crop yield have tripled in the last 50 years with climate models predicting that the frequency of such droughts will intensify in the future. Silicon (Si) accumulation, especially in Poaceae crops such as wheat (Triticum aestivum L.), may alleviate the adverse impacts of drought. We have very limited information, however, about whether Si supplementation could alleviate the impacts of drought under field conditions and no studies have specifically manipulated rainfall. Using field–based rain exclusion shelters, we determined whether Si supplementation (equivalent to 39, 78 and 117 kg ha-1) affected T. aestivum growth, elemental chemistry [Si, carbon (C) and nitrogen (N)], physiology (rates of photosynthesis, transpiration, stomatal conductance, and water use efficiency) and yield (grain production) under ambient and drought (50% of ambient) rainfall scenarios. Averaged across Si treatments, drought reduced shoot mass by 21% and grain production by 18%. Si supplementation increased shoot mass by up to 43% and 73% in ambient and drought water treatments, respectively, and restored grain production in droughted plants to levels comparable with plants supplied with ambient rainfall. Si supplementation increased leaf-level water use efficiency by 32–74%, depending on Si supplementation rates. Water supply and Si supplementation did not alter concentrations of C and N, but Si supplementation increased shoot C content by 39% and 83% under ambient and drought conditions, respectively. This equates to an increase from 6.4 to 8.9 tonnes C ha-1 and from 4.03 to 7.35 tonnes C ha-1 under ambient and drought conditions, respectively. We conclude that Si supplementation ameliorated the negative impacts of drought on T. aestivum growth and grain yield, potentially through its beneficial impacts on water use efficiency. Moreover, the beneficial impacts of Si on plant growth and C storage may render Si supplementation a useful tool for both drought mitigation and C sequestration.
ABSTRACTInfluenza, a negative sense single-strand RNA virus of the genus Orthomyxoviridae, causes respiratory illness in humans and animals and significant morbidity and mortality worldwide. While exposure to a specific influenza A strain causes homologous protection, two immune-dominant influenza A virus (IAV)-encoded epitopes - Hemagglutinin (HA) and Neuraminidase (NA) - undergo antigenic shift and drift, resulting in IAVs to which humans lack pre-existing immunity. Without a universal vaccine or therapeutic agent, influenza virus infections will significantly threaten human health. The extracellular domain of the Matrix protein 2-ion channel (M2e) is an ideal antigenic target for a universal influenza therapy: it is highly conserved across influenza A serotypes, has a low mutation rate, and is essential for viral entry and replication. However, less than 20% of humans generate M2e-specific antibodies in response to IAV exposure, thus lacking the benefits of M2e-MAb-mediated immunity. To therapeutically address this deficit, we generated several non-neutralizing M2e-specific monoclonal antibodies (M2e-MAbs) with strong universal IAV treatment potential. Using three MAbs that bind to M2e differentially and competitively, we developed a low-dose M2e-MAb triple cocktail as an effective universal prophylactic and therapeutic agent. We identified the low-dose M2e-MAb triple cocktail’s optimal antibody-clone combination, isotype, minimum effective dosage, and administration time points in mouse models challenged with human and zoonotic BSL-2 and BSL-3 IAV strains, demonstrating its universal potential. Using the IgG2a isotype, which had proven most effective, we established FcγRI, FcγRIII, and FcγRIV as required for M2e-MAb-mediated protection of IAV-challenged mice. Importantly, we established individual M2e-MAbs and the resulting triple cocktail as effective and viral escape mutant-resistant treatments in immunocompetent and immunodeficient mice. These unique qualities provide precedence for prioritizing our M2e-MAbs for therapeutic development.CONFLICT OF INTEREST STATEMENTSP serves on the scientific advisory board for Shoreline Biosciences, Qihan Biotechnology and is a Scientific Consultant for Qihan Biotechnology and the Genomics Institute of the Novartis Research Foundation. The remaining authors declare no competing interests.
Purpose Silicon (Si) accumulation by grasses alleviates diverse biotic and abiotic stresses. Despite this important functional role, we have limited understanding of how root microbial symbionts, such as arbuscular mycorrhizal (AM) fungi, affect Si uptake and even less about how Si supply and accumulation affect AM fungal colonisation. Our objective was to determine the nature of this two–way interaction in the model grass, Brachypodium distachyon. Methods We grew B. distachyon with five levels of Si supplementation using wild-type plants and a mutant ( Bdlsi1-1 ) that has little capacity for Si uptake. Half of the plants were colonised by AM fungi; half were free of AM fungi. We measured Si accumulation, AM fungal colonisation, leaf carbon (C), nitrogen (N) and phosphorus (P) concentrations. Results AM fungi did not affect Si accumulation, although small increases occurred when root mass was included as a covariate. Si supplemented soil promoted plant growth and P uptake. Si accumulation suppressed colonisation by AM fungi and C concentrations in wild type but not in Bdlsi1-1 plants. Si concentrations were negatively correlated with C and N concentrations, with correlations being stronger in wild-type plants than Bdlsi1-1 plants. Conclusions Our results indicate that Si accumulation in the plant, rather than Si availability in the soil, underpinned reduced AMF colonisation. We propose that Si accumulation is unlikely to be impacted by AM fungi in plants with inherently high Si accumulation, but Si accumulation may suppress AM fungal colonisation in such plants.
Aims Silicon (Si) uptake and accumulation improves plant resilience to environmental stresses, but most studies examining this functional role of Si have focussed on grasses (Poaceae) and neglected other important plant groups, such as legumes (Fabaceae). Legumes have evolved a symbiotic relationship with nitrogen-fixing bacteria (rhizobia) housed in root nodules. Our study determined the impacts of silicon (Si) supplementation on Medicago truncatula inoculated with Ensifer meliloti rhizobial strains that differed in their capacity for nitrogen fixation: Sm1021 (‘low-efficiency’) or Sm1022 (‘high-efficiency’). Methods We examined how Si and rhizobial efficacy influence nodule and plant functional traits, including their chemical aspects. These combinations were supplied with or without Si in a glasshouse experiment, where we quantified nodule flavonoids and foliar chemistry (free amino acids, soluble protein, elemental C, N and Si). Results Si supply increased nodule number per plant, specific nodule flavonoid concentrations, contents of foliar nitrogenous compounds and foliar C, but not foliar Si. We also demonstrated that rhizobial efficacy altered the magnitude of Si effects on certain traits. For example, Si significantly promoted concentrations of foliar N and soluble protein in the plants associated with the ‘low-efficiency’ strain only, and this was not the case with the ‘high-efficiency’ one. Conclusions Collectively, our study indicates that Si generates positive effects on M. truncatula , particularly when the association with rhizobia is relatively inefficient, and may play a more prominent role in rhizobial functionality than previously thought.
Silicon accumulation is a key defence against herbivorous pests, but may have wider detrimental impacts if plants become unpalatable for livestock. We argue that some herbivores are better adapted to silicon-rich diets than others; herbivore anatomy and physiology, and the nature of silicon deposition, are crucial to understanding these differences.