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Article

Effects of Acetylsalicylic Acid and Biosolids on Edaphic, Vegetative and Biochemical Parameters of Amelichloa caudata Under Water Shortage Conditions

by
Julio Molina
1,2,*,
Fernando Silva-Romano
1,
Irina M. Morar
2,3,
Monica Boscaiu
2,*,
Claudia Santibáñez
4 and
Josep V. Llinares
2
1
Escuela de Agronomía, Facultad de Ciencias, Universidad Mayor, Camino La Pirámide 5750, Huechuraba 8580745, Chile
2
Mediterranean Agroforestry Institute (IAM), Universitat Politècnica de València, Camino de Vera s/n, 46022 Valencia, Spain
3
Department of Forestry, University of Agricultural Sciences and Veterinary Medicine, Calea Manastur 3-5, 400372 Cluj-Napoca, Romania
4
Centro de Investigación para la Sustentabilidad, Facultad de Ciencias de la Vida, Universidad Andres Bello, República 440, Santiago 7550196, Chile
*
Authors to whom correspondence should be addressed.
Agronomy 2025, 15(4), 785; https://doi.org/10.3390/agronomy15040785
Submission received: 6 March 2025 / Revised: 20 March 2025 / Accepted: 21 March 2025 / Published: 23 March 2025
(This article belongs to the Section Plant-Crop Biology and Biochemistry)
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Versions Notes

Abstract

:
Water scarcity has affected much of Chile for the past 15 years, and Amelichloa caudata, a native species adapted to arid conditions, may offer a solution. The hypothesis of this study is that both acetylsalicylic acid (ASA) and biosolids (BSs) can positively influence plant growth under water stress. This study assessed the effects of ASA and BSs on edaphic, physiological, biochemical, and productive parameters of A. caudata under water scarcity conditions. Results showed that both treatments enhanced biomass production, plant height, leaf number, and canopy weight. ASA improved water retention, mitigating water stress effects and leading to biomass levels comparable to controls. In contrast, BSs did not show significant benefits and had the lowest biomass values under all conditions. The highest root dry weight was observed in water-restricted plants, while ASA-treated plants had lower malondialdehyde (MDA) levels, indicating reduced oxidative stress. However, BS treatment increased MDA levels, suggesting more severe oxidative damage. Despite improvements in water retention, high salt concentrations in BSs may limit their effectiveness and further research is required to optimize application rates.

1. Introduction

Recent climate change projections for Chile indicate rising temperatures and decreasing annual rainfall across much of the northern and central regions, contributing to desertification and reduced water availability for plants [1,2]. Drought remains one of the major constraints to agricultural development, particularly in arid and semi-arid regions, where it severely impacts crop yields. Reduced soil water content disrupts plant growth and water relations, interfering with physiological processes. This leads to alterations in turgor and osmotic pressure, reduced chlorophyll content, and subsequent declines in photosynthetic rates, carbon capture and assimilation, gas exchange, and overall biomass production [3,4]. In response to drought stress, plants deploy various defence strategies, including enhanced water uptake via deep and extensive root systems, as well as the development of smaller, succulent leaves to minimize transpiration losses. Potassium ions contribute to osmotic adjustment, while low-molecular-weight compatible solutes—such as proline, other amino acids, glycine betaine, organic acids, and polyols—play a crucial role in maintaining cellular functions during drought. Additionally, plant growth regulators like salicylic acid, auxins, gibberellins, cytokinins, and abscisic acid are involved in the plant’s defence mechanisms against water stress [3].
Plant drought tolerance can be enhanced through various strategies, including the exogenous application of substances, plant growth-promoting bacteria, and mycorrhizal fungi [5]. Acetylsalicylic acid (ASA), commonly known as aspirin, is a derivative of salicylic acid. When applied externally, ASA undergoes spontaneous hydrolysis and is converted into salicylic acid (SA) [6]. SA serves multiple functions, acting as a signalling molecule and modulator of redox balance across membranes, thereby mitigating the negative effects of reactive oxygen species (ROS) accumulation caused by oxidative stress. SA has been shown to enhance drought tolerance in various plant species and to increase resilience to a range of abiotic stresses [7,8]. Exogenous SA treatment can influence several plant processes, including seed germination, stomatal closure, ion uptake and transport, membrane permeability, photosynthesis, and growth rates [9].
Biosolids (BS), the main by-product of the wastewater treatment process, have been shown to have a significant effect on water retention and fertility improvement in applied soils [10], as well as providing an alternative to fertiliser use. Their use can facilitate decreases in their accumulation after municipal wastewater processing and treatment [11,12]. When added to degraded soils, biosolids lead to medium- to long-term improvements in soil physical and chemical parameters and biological fertility, especially when applied at low doses due to the risk of contamination if not properly disposed of [13,14,15]. With the advantage of using waste, biosolids—processed solids from municipal wastewater treatment plants—are applied to agricultural land in several countries, either in place of or as a complement to traditional fertilisation regimes. Biosolids release nitrogen more slowly than chemical fertilisers, which can increase their ability to provide plants with accessible nitrogen over a longer period and reduce the amount of nitrogen entering watercourses. Although they may contain heavy metals, they are also a source of other nutrients, such as phosphorus [16]. In Chile, the production of biosolids has grown dramatically in the last ten years, and their disposal has become an environmental concern. The alternatives to incineration are landfilling or their use as fertiliser in forestry plantations [17] or biofuel crops, which often require nitrogen fertilisers to compensate for low nitrogen use efficiency and high nitrogen demand [16]. The use of biosolids as fertiliser for biofuel crops or in restoration programmes avoids their translocation through the food chain and, as such, reduces concerns related to their potential toxicity, as they may contain low concentrations of heavy metals [16].
Amelichloa caudata (Trin.) Arriaga & Barkworth (syn. Stipa caudata Trin.) is a perennial grass of the family Poaceae, 55 to 100 cm tall, occasionally up to 1.5 m. The species is native to Chile, Argentina, and Uruguay. It is mainly found in the mesothermic grassland zone delimited by the southern border of Brazil, Uruguay, Chile and central Argentina between 28° and 40° S, a region characterised by mean annual temperatures of 10 to 20 °C and mean winter temperatures of 5 to 15 °C. It also grows in the micro-thermal zone with annual temperatures below 10 °C and average winter temperatures below 5 °C. It is a species adapted to the predominantly arid conditions of the eastern mountains and temperate regions of southern South America [18]. The species was introduced to other continents and is reported to be invasive, competing with native vegetation in grasslands, open woodlands, forests and riparian vegetation in Spain [19] and Italy [20].
There is limited information on the physiological responses of Amelichloa caudata to drought and on strategies to enhance its biomass production under water scarcity conditions [21]. Furthermore, no studies have explored the effects of biosolids on its growth. This study aimed to assess the individual and combined effects of acetylsalicylic acid (ASA) and biosolids on edaphic, physiological, biochemical, and productive parameters of Amelichloa caudata under water-limited conditions. Ion content was measured in both roots and leaves, while the compatible solute proline, oxidative stress markers (malondialdehyde), and antioxidants (phenolic compounds and flavonoids) were quantified in foliar tissue.

2. Materials and Methods

2.1. Study Site and Experimental Conditions

The research was conducted during the 2019 and 2020 growing seasons using Amelichloa caudata plants collected from the Commune of La Pintana, Metropolitan Region, Santiago, Chile (33°26′40.42″ S, 70°39′3.43″ W). The plants were uprooted in April from the locality of La Pintana, Metropolitan Region, Santiago, Chile (33°57′18.39″ S 70°63′15.75″ W), where they grow spontaneously. Prior to the trial, the plants were conditioned in the greenhouse and fertilised with a nutrient solution based on 0.1% total N and 3% K at a dose of 1.5 L ha−1. At the beginning of the trial, the plants were pruned to a height of 10 cm above the potting substrate. They were then individually transplanted into 1 L pots (1 plant per pot) filled with Andisol soil from the foothills (19% clay, 26% silt, 55% sand; pH = 7.2, EC = 0.47 dS/m, organic matter = 1.5%) from the commune of Rinconada de Los Andes, Valparaíso Region, Chile (32°52′00.42″ S, 70°43′37.29″ W). The “Class B” biosolids (BSs) used in the treatments were sourced from the “El Treba” sewage treatment plant, operated by Aguas Andinas, located in the commune of Padre Hurtado, Santiago, Chile. The composition of the biosolids used is shown in the Supplementary Table S1. Before incorporation into the soil, the activated sludge was dried, disaggregated, and sieved to a size of less than 2 mm (Supplementary Figure S1). The analyses were conducted at the Faculty of Sciences, Universidad Mayor, Santiago, Chile, during the 2019 season, and at COMAV, Universitat Politècnica de València, Spain, in the 2020 season. The plants were acclimated for four weeks under greenhouse conditions, with weekly watering until they reached field capacity (FC). Four weeks before the start of the experiment, a basal fertilisation was applied to the soil with a nutrient solution containing 0.1% total nitrogen and 3% K+, at a dose of 1.5 L ha−1. The trial took place in October, when both ambient and greenhouse temperatures were higher (25–20 °C, with an average of 23 °C), and the average relative humidity was 53%.

2.2. Experimental Design and Treatments of Plants

At the start of the treatments, the plants were pruned to a height of 10 cm (see Supplementary Figure S2) and treated via foliar application with 1 mM acetylsalicylic acid (ASA) and a dose of 200 tons/ha of biosolids (BSs) following the dosages used in previous studies [21,22]. The treatments were applied to two groups of plants: irrigated plants (Irrigated), which received distilled water up to field capacity (FC); and non-irrigated water-restricted plants (WR). The trial was concluded after 14 days, when 90% of the WR plants exhibited severe chlorosis symptoms. The experimental design comprised split plots in random blocks (Table 1), in which the main plot corresponded to the water condition (Irrigated or WR) and the subplot to the treatments (ASA + BS, ASA, BS, Control). The treatment structure was factorial (two factors), with two levels each (8 treatments) and 8 replicates for each, in which each plant of Amelichloa caudata in a pot represented one experimental unit and the number of pots in each experimental variant was 4.

2.3. Soil Characteristics

The soil pH in each pot was determined once a week, using a portable pH meter (60 AF, Shenzhen, China). The electrical conductivity of the soil in each pot was also determined once a week, using a portable conductivity meter (EC-1385 ATC, Qingdao, China). The volumetric water content was measured weekly in each pot by means of a metal probe (PM5710, Shenzhen, China), which was introduced to a depth of three-quarters of the total depth of the pot, making sure that the sensor was completely covered, at an equal distance between the inner face of the pot and the crown of the plant, and taking care not to damage the root system.

2.4. Vegetative Growth of Plants

Cumulative shoot length was measured weekly by recording the length of five vegetative shoots per plant from the base to the tip using a tape measure. Similarly, cumulative leaf width was measured weekly at the middle zone of five leaves per plant using a digital calliper. Cumulative leaf thickness was assessed weekly by measuring the thickness at the basal, middle, and apical zones of five leaves per plant, with the final average calculated using a digital calliper. At the end of the season, both fresh and dry biomass were determined by weighing the stems and roots. Plants were initially weighed fresh and then dried in an oven at 70 °C for 72 h to obtain the dry weight, which was measured using a digital balance.

2.5. Ion Content in Roots and Shoots of Plants

At the end of the assay, Na+, K+ and Cl− contents were measured according to the method of Weimberg [23] in liquid extract obtained from heating water (0.15 g of dry plant material in 10 mL of water) in a water bath for 1 h at 95 °C. Cations were analysed with a flame photometer (Corning 410 C), while Cl− was measured with a chloride analyser (Corning 926).

2.6. Malondialdehyde (MDA), Antioxidant Compounds and Osmolyte Quantification

MDA content was quantified in the shoots. A 0.01 g sample of fresh tissue was ground in a mortar to obtain a fine powder, and 1.5 mL of 80% methanol was used as the extractant. The samples were gently shaken overnight at 7 °C. The supernatant was then collected by centrifugation at 13,300 rpm for 10 min at 4 °C and stored at −20 °C until use in the assays. MDA in the extracts was quantified by the trichloroacetic/thiobarbituric acid method as described by Hodges et al. [24]. At the end of the assay, total phenolic compounds (TPC) and total flavonoids (TF) were measured in the same methanol extract. TPCs were quantified by measuring absorbance at 765 nm after reaction with Folin Ciocalteu’s reagent, according to Blainski et al. [25], expressed as gallic acid equivalents (mg eq. GA g DW−1), and these values were used to obtain the standard curve. TFs were measured following the procedure described by Jia Zhishen et al. [26] based on the nitration of aromatic rings bearing a catechol group and their reaction with AlCl3; this method detects antioxidants, but also other phenolics containing a catechol group. After the reaction, the absorbance of the sample was measured at 510 nm, and the amount of flavonoids was expressed as catechin equivalents (mg eq. Catec. g DW−1).
Proline (Pro) content in the fresh plant material was determined by the ninhydrin-acetic acid method described by Bates et al. [27]. Pro was extracted in 3% aqueous sulfosalicylic acid; the extract was then mixed with an acid ninhydrin solution, incubated for 1 h at 95 °C, cooled on ice, and then extracted with two volumes of toluene. The absorbance of the organic phase was measured at 520 nm, using toluene as a blank. The concentration of Pro was expressed as µmol g−1 DW.

2.7. Statistical Analysis

The experimental results were analysed using linear and mixed models to assess significant differences between treatments. A Fisher’s test was applied for mean comparisons with 95% confidence to determine differences between treatments. Temporal correlations for variables such as growth, width, thickness, pH, and EC were incorporated into the model during the analyses. Data analysis was performed using the R programming language (R Core Team 2023) and the statistical software InfoStat [28].

3. Results

3.1. Vegetative Growth

The results indicate that water status positively affected all the variables analysed under irrigated conditions, while the treatments influenced the aerial part fresh weight and root dry weight (Supplementary Figures S3–S5). Regarding shoot length, no significant effect was observed in the treated plants (Figure 1A). However, irrigated plants exhibited a significant increase in length compared to the non-irrigated (WR) plants (Figure 1B). A similar pattern was observed for leaf width (Figure 1C,D) and leaf thickness (Figure 1E,F).
Figure 2A shows the results for leaf fresh weight. Treated plants did not exhibit significant differences in leaf fresh weight; however, the irrigated plants showed a significant increase in canopy weight compared to the non-irrigated plants (Figure 2B). In terms of leaf dry weight, significant differences were observed among treated plants, with the Control and ASA plants exhibiting the highest dry weights, while the ASA/BS and BS plants had the lowest (Figure 2C). Additionally, the irrigated plants had higher leaf weights compared to the WR plants (Figure 2D).
It is noteworthy that the treated plants exhibited lower root biomass compared to the control plants. Significant differences were observed in root fresh weight, with the control plants showing the highest root biomass, followed by BS plants, while the ASA/BS and ASA plants had the lowest root fresh weight (Figure 3A). Regarding root dry weight, an interaction between the factors was observed. Control WR plants had the highest dry weight compared to the other treatments, while the ASA/BS mixture under WR conditions had the lowest root dry weight. The other treatments fell in intermediate positions (Figure 3B).

3.2. Soil and Water Status

Despite increasing the water content in the substrate and reducing the pH of the soil solution, the addition of BSs raised the electrical conductivity, potentially beyond the species tolerance limits, which affected its growth. Figure 4A,B show the accumulated pH values of the soil solution in Amelichloa caudata measured throughout the experiment. No significant differences were found for water status (WS); however, pots treated with BS showed significant differences. Specifically, the ASA/BS-treated pots had the lowest pH values, while the Control and ASA pots had higher pH, with BS plants occupying an intermediate position. Regarding electrical conductivity (EC), the Control and ASA pots exhibited significantly lower values compared to the BS and ASA/BS treatments (Figure 4C). Additionally, the WR pots accumulated more salt than the irrigated ones (Figure 4D).
Regarding the volumetric water content in the soil, BS and ASA/BS showed significantly higher values compared to Control treatments, while ASA had intermediate values (Figure 5A). On the other hand, there were significant differences with respect to water status, where the WR pots showed lower levels of this variable compared to the Irrigated pots (Figure 5B).

3.3. Ion Concentrations in Plants

The Irrigated ASA + BS plants exhibited the highest ion concentrations, while the other treatments under WR conditions had the lowest. For Cl−, the WR ASA plants had the highest concentrations in the roots, while the WR BS plants had the lowest. Table 2 presents the Na⁺, Cl−, and K⁺ contents in the roots, where significant differences were observed for the interaction between treatments (A) and water status (B) regarding Na⁺ and Cl− contents. However, no significant differences were found for either factor or their interactions in relation to K⁺ content.
Regarding the significant differences in the interaction (A × B) for Na⁺ content shown in Table 2, the ASA/BS Irrigated treatment exhibited the highest accumulation levels compared to the other treatments. In contrast, the BS and ASA Irrigated treatments displayed intermediate levels, while the remaining treatments had the lowest Na⁺ levels in their root tissue (Figure 6A). Similarly, Figure 6B shows the interaction between treatments (A) and water status (B) for the accumulated Cl− content in the roots. Plants treated with ASA WR, along with the Control Irrigated and Control WR plants, had the highest Cl− levels, while BS WR and ASA/BS WR had the lowest, with ASA and BS treatments falling in between.

3.4. Malondialdehyde (MDA), Antioxidant Compounds and Osmolyte Quantification

No significant differences were found in the accumulation of total phenolic compounds and total flavonoids. However, WR plants, regardless of the treatments, showed a higher accumulation of proline (Pro). Although no significant differences were observed, ASA-treated plants also exhibited the highest proline content. Table 3 presents the contents of total phenolic compounds (TCF), total flavonoids (TF), malondialdehyde (MDA), and proline (Pro) in the shoots. No statistically significant differences were found for factors A (treatments) and B (water status) or for their interaction concerning TCF and TF contents, nor for the AxB interaction concerning MDA and Pro. However, significant proline accumulation was observed with respect to different water statuses, and significant differences were also found for MDA levels based on both treatments (A) and water status (B).
Figure 7 shows the statistically significant differences in proline (Pro) content with respect to the water status factor. No significant differences were observed for the treatment factors (Figure 7A), but the WR plants exhibited higher levels of proline compared to irrigated plants (Figure 7B).
Irrigated plants exhibited the highest levels of malondialdehyde (MDA), a marker of oxidative stress, with levels similar to those treated with biosolids (BSs), while the acetylsalicylic acid (ASA) and control treatments resulted in the lowest MDA values. Specifically, plants treated with BSs accumulated more MDA compared to those treated with ASA and the control group. Regarding the significance of factor A in terms of malondialdehyde (MDA) content in shoots, plants treated with BSs showed a higher accumulation of this stress indicator, whereas plants treated with ASA and Control showed the lowest levels (Figure 8A). Significant differences were found with respect to the water status factor (B), where Irrigated plants showed higher levels than WR plants (Figure 8B).

4. Discussion

Amelichloa caudata, a grass species native to arid regions, is of significant economic importance. Given the climatic variability in its native habitat, improving its water-use efficiency is essential. Strategies such as applying phytohormones like acetylsalicylic acid (ASA) and incorporating biosolids (BSs) have been investigated to enhance drought tolerance and reduce biomass loss under water-limiting conditions. ASA-treated plants showed the highest canopy dry weight, comparable to controls, and demonstrated better growth under water stress, with increased biomass and reduced oxidative damage. In contrast, biosolid (BS) treatments consistently resulted in lower biomass and higher oxidative stress. Both treatments influenced root ion content, but ASA showed a more positive impact on plant resilience to water scarcity.

4.1. Effects of ASA and BSs on Plants

Acetylsalicylic acid is known to influence plant stress responses through its role as a salicylic acid (SA) precursor. Salicylic acid is a plant hormone that plays a key role in regulating plant defence mechanisms, including responses to abiotic stress such as drought. SA functions as a key signalling molecule in plants, triggering a cascade of molecular events and modulating various stress-responsive pathways, including the activation of antioxidant defence systems, osmotic regulation, and the regulation of gene expression related to stress tolerance [29,30,31]. The molecular mechanisms underlying SA’s action in abiotic stress involve several important molecular players, including transcription factors, proteins, and secondary metabolites that act in concert to enhance plant resilience [31,32]. Proteomic studies have identified more than 150 proteins that are differentially expressed in response to SA treatment, many of which are involved in abiotic stress responses such as antioxidant defence, ion transport, and protein synthesis [33,34]. Among the most notable proteins are the 14-3-3 transcription factors, which play a pivotal role in regulating plant responses to environmental stressors by modulating the activity of several target proteins involved in signal transduction and stress adaptation [31]. Additionally, proteins with NAC (NAM, ATAF, and CUC) domains have been found to be upregulated by SA under stress conditions, highlighting their involvement in the regulation of stress-related genes [35]. NAC proteins function as key regulators of stress tolerance, particularly under drought and salinity stress, by controlling the expression of genes involved in cell wall modification, stress-responsive enzyme activity, and osmotic adjustment [36,37]. Positive results have been observed for the plant height and biomass of tomato (Lycopersicon esculentum), wheat (Triticum aestivum), chickpea (Cicer arietinum), Eragrostis plana, and Amelichloa caudata when subjected to ASA-treated stress conditions [21,38,39,40]. Additionally, some plants exhibit resistance to various stressors by thickening the epidermis or increasing leaf width, as observed in olive trees and drought-resistant wheat varieties [41,42].
Biosolids, which are nutrient-rich organic materials derived from sewage sludge, also exert a significant influence on plant stress responses. The application of biosolids to soil has been shown to enhance the physiological and biochemical properties of plants under abiotic stress [43]. Biosolids improve soil structure, increase nutrient availability, and stimulate microbial activity, all of which contribute to enhanced plant growth and stress resilience. In addition, biosolids may influence the expression of defence-related genes and proteins, thereby boosting the plant’s ability to tolerate various stressors. Recent studies have reported that biosolid-amended soils enhance defence responses in plants such as tomatoes by influencing the expression of pathogenesis-related genes, which also contribute to abiotic stress tolerance [44]. This suggests that biosolid amendments may act as an additional source of stress-regulating compounds, further enhancing the plant’s ability to withstand environmental challenges. Trippe et al. [45] observed increases in both aerial and root biomass in Elymus glaucus treated with a BS mixture, relative to a lime-substrate control. Furthermore, increases in dry weight were noted in Hordeum vulgare, Triticum aestivum, and Avena byzantina compared to control plants, though these increases were not observed in plants subjected to traditional fertilisation [46]. However, no significant differences in biomass were noted in Raphanus sativus, Lactuca sativa, and Festuca arundinacea when treated with BSs [47]. However, in our study, BSs did not show the same positive effects as ASA on biomass production. The high salt concentrations in BSs, may have led to osmotic stress and ion toxicity. Salt stress can interfere with water uptake and cause ion imbalance in plant cells, reducing overall plant growth and leading to oxidative damage.

4.2. Soil and Water Status

On the other hand, biosolid (BS) treatments have been shown to enhance various physical parameters, such as soil porosity, as well as chemical and biological properties, including an increase in the number of beneficial bacterial colonies [48,49]. Soil salinity is primarily determined by the concentration of soluble ions, such as Na+, K+, Ca2⁺, Mg2⁺, and Cl−, among others [50]. In this context, washing biosolids and municipal solid waste prior to soil incorporation has proven to be an effective method for reducing salt concentrations [50,51], as leaching water typically contains ions like Na+ and Cl− [52]. Conversely, BS applications at lower doses in similar soils have shown comparable effects on the electrical conductivity of treated soils [13]. Given this, it is possible that the dosage used in the present study may have been too high, and a combination of pre-washing the BSs and reducing the application rate might mitigate the negative impact on plant growth observed. Additionally, the BS treatments resulted in dark brown roots with necrotic lesions at the end of the experiment, in contrast to the control plants. Such lesions are commonly observed in plants exposed to high concentrations of transition metals, and these plants also typically exhibit a reduction in root development [53,54]. It is likely that the contact between roots and these elements contributed to the observed inhibition of root growth.

4.3. Ion Concentrations in Plants

Increased shoot Na+ content under water-deficient conditions has been reported in wheat (Triticum aestivum) [55], as well as in Arabidopsis thaliana expressing the TNHX1 and TVP1 genes from wheat (Triticum aestivum) [56]. However, lower Na+ levels in wheat roots under salt and water stress have also been documented [57]. Regarding ASA applications, a reduction in Na+ accumulation under water stress has been observed in wheat (Triticum aestivum) [58] and in subsequent studies [59]. On the other hand, decreases in Na+ and Cl− content have been reported in rice (Oryza sativa) [60], as well as in maize (Zea mays) [61,62]. Conversely, some studies have indicated increased Na+ and Cl− contents in wheat (Triticum aestivum) plants under stress conditions [63]. Additionally, water-restricted (WR) treatments that incorporated BSs demonstrated lower Na+ and Cl− accumulation in plant biomass. Reduced Na+ accumulation under stress has also been observed in stress-resistant Cajanus cajan genotypes [64], with similar trends reported for Na+ content in soybean (Glycine max) [65]. Decreases in Na+ and Cl− contents in soils fertilised with municipal sludge have been described in Spinacia oleracea [66]. Positive correlations have been observed between root Cl− content, leaf Na+ content, and root K+ content. Increased Na+ content occurs under water deficit conditions due to a reduction in the uptake of other essential cations [58]. However, the presence of salicylic acid can alter the Na+ uptake balance by promoting the absorption of other essential cations, thereby reducing that of Na+ [31,67].
The selective ability of plants to discriminate between the ions they absorb is well established. In this regard, it is likely that Amelichloa caudata, when exposed to ASA, increased its ion selectivity, minimizing Na+ uptake, since it is a non-essential element that could potentially cause cellular damage [68]. However, the WR ASA-treated plants tended to accumulate more internal Cl−. Although Cl− is generally toxic to most plants [68], it plays a crucial role in stomatal regulation alongside K+, helping to balance water regulation under stress conditions [69]. On the other hand, plants grown in BS substrates exhibited lower Na+ and Cl− accumulation. Given that approximately half of the biosolid matrix consists of organic matter [70], this effect could be attributed to electrostatic retention by the applied organic matter [71], as well as to ion competition within the biosolids [72], which would limit the uptake of non-essential cations and anions, such as Na+ and Cl− [68].

4.4. Biochemicals Parameters

Increased proline (Pro) content has been reported under water stress conditions across a wide range of plant species [73,74,75], including Amelichloa caudata [21]. Additionally, plants treated with salicylic acid (SA) typically exhibit enhanced proline accumulation. Proline is a compatible solute that accumulates in response to water stress, functioning as a protective molecule that stabilises proteins and cellular membranes. Salicylic acid treatment has been shown to promote proline biosynthesis by upregulating key genes involved in proline synthesis, such as P5CS1, P5CS2, and P5CR [76]. The accumulation of proline plays a crucial role in maintaining osmotic balance, thereby improving water retention and supporting plant growth under drought conditions [77]. For instance, the application of salicylic acid has been linked to increased expression of the drought-resistance gene P5C5 in Triticum aestivum [78], as well as an elevation in proline content in cold-stressed wheat leaves [79].
One of the initial responses of plants to various environmental stresses is the accumulation of reactive oxygen species (ROS). Under normal conditions, ROS function as signalling molecules, regulating various metabolic and physiological processes. However, under stress conditions, their accumulation is markedly increased, often resulting in oxidative damage at the cellular level [80]. The accumulation of malondialdehyde (MDA), a product of lipid peroxidation, is a common indicator of membrane damage. Elevated MDA levels have been observed under water stress in multiple species, including Juncus acutus, J. articulatus [75], rice [81], and wheat [82]. Interestingly, increased MDA content has also been recorded in irrigated plants compared to water-stressed plants, as demonstrated in Carica papaya [83]. Salicylic acid (SA) is known to activate antioxidant defence systems by enhancing the activity of several key antioxidant enzymes [84,85,86]. Molecular evidence supporting this effect includes the upregulation of antioxidant-related gene expression, with SA acting as a signalling molecule in the plant’s response to abiotic stress [29].
Biosolids have been reported to reduce malondialdehyde (MDA) concentrations in plants treated with these materials [87]. However, under the conditions of the present experiment, MDA levels in the biosolid (BS)-treated plants increased, consistent with findings from a previous study on Vicia faba [88]. This increase may be attributed to the elevated salinity caused by biosolid application, which could overwhelm the plant’s antioxidant defence mechanisms, leading to membrane damage. Additionally, biosolids may contain high levels of nitrogen compounds that contribute to nutrient imbalances and nitrogen toxicity [89]. Although biosolids are a source of essential macronutrients (N, P, K) and micronutrients (Fe, Zn, Cu), their high salt content can interfere with nutrient uptake and induce osmotic stress. This, in turn, exacerbates oxidative stress by promoting the accumulation of reactive oxygen species (ROS). Furthermore, biosolids may alter soil microbial communities, which are crucial for nutrient cycling [90]. While such changes can sometimes enhance plant growth, microbial imbalances—particularly those induced by high salinity or contamination—can adversely affect plant development. This may explain the reduced biomass observed in plants treated with biosolids in the present study.
When combining ASA with biosolids, the plants could potentially benefit from the nutrient boost provided by BSs, but the high salt content may limit the overall benefits. The protective effects of ASA on oxidative stress could help mitigate some of the damage caused by the salinity in BSs, but this would depend on the ratio of ASA to BSs and the severity of the water stress.

5. Conclusions

Plants treated with acetylsalicylic acid (ASA) showed the highest canopy dry weight, comparable to controls, while biosolid (BS) treatments consistently produced the lowest values, regardless of water conditions. For root dry weight, a significant interaction between water regime and treatment was observed, with water-restricted (WR) plants showing the highest root dry weight. However, the WR ASA-treated plants exhibited growth similar to irrigated plants, suggesting that ASA improved growth under water stress. Both the control and WR plants showed increased total biomass, but without an increase in stem thickness, which was seen in ASA-treated plants, indicating greater resilience to WR conditions.
Regarding ion content, irrigated plants treated with ASA and BSs had the highest values, while WR plants had lower ion content. The WR ASA-treated plants had the highest chloride (Cl−) concentrations, while the BS-treated plants showed the lowest. No significant differences were observed in total phenolic compounds or flavonoids, suggesting minimal influence from the treatments under the conditions tested.
The WR plants had the highest proline content, with ASA-treated plants showing the greatest accumulation, although the differences were not statistically significant. The ASA-treated plants had the lowest malondialdehyde (MDA) levels, indicating reduced oxidative damage, while BS-treated plants exhibited the highest MDA, suggesting greater oxidative stress.
Although ASA has well-established positive effects, biosolids require further investigation due to their high salt content, which may reduce their effectiveness by increasing soil salinity. This could hinder nutrient uptake and water absorption, particularly in salt-sensitive plants. Further research should explore optimal biosolid application rates, potential pre-treatment methods to mitigate salt impacts, and the long-term effects on soil properties. Identifying thresholds for biosolid application and understanding plant species responses to varying salinity levels will help develop more effective agricultural strategies.

Supplementary Materials

The following supporting information can be downloaded at: https://www.mdpi.com/article/10.3390/agronomy15040785/s1. Figure S1: Biosolid used in the test; Figure S2: Plants during the treatments; Figure S3·: Roots sampled at the end of the treatments; Figure S4: Irrigated plants under different treatments; Figure S5: Water restricted plants under different treatments; Table S1: Chemical analysis of the biosolids used in the study.

Author Contributions

Conceptualization, J.V.L., M.B. and C.S.; methodology, J.M., F.S.-R. and I.M.M.; software, J.M.; validation, J.V.L. and C.S.; formal analysis, J.M.; investigation, J.M., F.S.-R. and I.M.M.; resources, J.M.; data curation, J.M. and F.S.-R.; writing—original draft preparation, J.M.; writing—review and editing, M.B., J.V.L. and C.S.; visualization, J.M.; supervision, M.B. and J.V.L.; project administration, C.S.; funding acquisition, J.M. and C.S. All authors have read and agreed to the published version of the manuscript.

Funding

Fondo de Incentivo para la Publicación (FDP), Universidad Mayor, Chile.

Data Availability Statement

The dataset is available upon request.

Conflicts of Interest

The authors declare no conflicts of interest.

References

  1. Hood, R. Global Warming. In A Companion to Applied Ethics; Blackwell Publishing Ltd.: Hoboken, NJ, USA, 2007; pp. 674–684. [Google Scholar] [CrossRef]
  2. Araya-Osses, D.; Casanueva, A.; Román-Figueroa, C.; Uribe, J.M.; Paneque, M. Climate Change Projections of Temperature and Precipitation in Chile Based on Statistical Downscaling. Clim. Dyn. 2020, 54, 4309–4330. [Google Scholar] [CrossRef]
  3. Farooq, M.; Wahid, A.; Kobayashi, N.; Fujita, D.; Basra, S.M.A. Plant Drought Stress: Effects, Mechanisms and Management. Agron. Sustain. Dev. 2009, 29, 185–212. [Google Scholar] [CrossRef]
  4. Vaishnav, A.; Arya, S.S.; Choudhary, D.K. Plant Stress Mitigators: Action and Application; Springer Nature: Singapore, 2022; ISBN 9789811677595. [Google Scholar]
  5. Ilyas, M.; Nisar, M.; Khan, N.; Hazrat, A.; Khan, A.H.; Hayat, K.; Fahad, S.; Khan, A.; Ullah, A. Drought Tolerance Strategies in Plants: A Mechanistic Approach. J. Plant. Growth. Regul. 2021, 40, 926–944. [Google Scholar] [CrossRef]
  6. Popova, L.; Pancheva, T.; Uzunova, A. Salicylic Acid: Properties, Biosynthesis and Physiological Role. Bulg. J. Plant Physiol. 1997, 23, 85–93. [Google Scholar]
  7. Korkmaz, A.; Uzunlu, M.; Demirkiran, A.R. Treatment with Acetyl Salicylic Acid Protects Muskmelon Seedlings against Drought Stress. Acta Physiol. Plant. 2007, 29, 503–508. [Google Scholar] [CrossRef]
  8. Chattha, M.U.; Iqbal, L.; Khan, I.; Wang, L.H.; Nawaz, M.; Ali, B.; Fang, S.; Ul Haq, M.I.; Hassan, M.U.; Rasheed, A.; et al. Regulating Effects of Exogenous Salicylic Acid Application on Wheat Growth Under Saline and Heat Stress Conditions. Appl. Ecol. Environ. Res. 2024, 22, 1315–1337. [Google Scholar] [CrossRef]
  9. Kabiri, R.; Naghizadeh, M. Exogenous Acetylsalicylic Acid Stimulates’ Physiological Changes to Improve Growth, Yield and Yield Components of Barley under Water Stress Condition. J. Plant Physiol. Breed. 2015, 5, 35–45. [Google Scholar]
  10. Sierra, J.; Roig, N.; Martí, E.; Nadal, M.; Schuhmacher, M. Amendment of Soils with Composted Sewage Sludge. Long Term Effects on C and N Transformation. In Environmental Science and Engineering; Springer: Berlin/Heidelberg, Germany, 2012; pp. 271–282. [Google Scholar] [CrossRef]
  11. Cieślik, B.M.; Namieśnik, J.; Konieczka, P. Review of Sewage Sludge Management- Standard, Regulations. J. Clean. Prod. 2015, 90, 1–15. [Google Scholar] [CrossRef]
  12. Sharma, B.; Sarkar, A.; Singh, P.; Pratap, R. Agricultural Utilization of Biosolids: A Review on Potential Effects on Soil and Plant Grown. Waste Manag. 2017, 64, 117–132. [Google Scholar] [CrossRef]
  13. Antilén, M.; Silva, K.; Acevedo, S.; Amiama, F.; Faúndez, M.; Knicker, H.; Pizarro, C. Characterization of Humic Acids Extracted from Biosolid Amended Soils. J. Soil. Sci. Plant Nutr. 2014, 14, 1005–1020. [Google Scholar] [CrossRef]
  14. Bettiol, W.; Ghini, R. Impacts of Sewage Sludge in Tropical Soil: A Case Study in Brazil. Appl. Env. Soil. Sci. 2011, 2011, 212807. [Google Scholar] [CrossRef]
  15. Lu, Q.; He, Z.L.; Stoffella, P.J. Land Application of Biosolids in the USA: A Review. Appl. Environ. Soil. Sci. 2012, 2012, 201462. [Google Scholar] [CrossRef]
  16. Adair, K.L.; Wratten, S.; Barnes, A.M.; Waterhouse, B.R.; Smith, M.; Lear, G.; Weber, P.; Pizey, M.; Boyer, S. Effects of Biosolids on Biodiesel Crop Yield and Belowground Communities. Ecol. Eng. 2014, 68, 270–278. [Google Scholar] [CrossRef]
  17. Donoso, S.; Peña-Rojas, K.; Pacheco, C.; Durán, S.; Santelices, R.; Mascaró, C. The Physiological and Growth Response of Acacia Caven under Water Stress and the Application of Different Levels of Biosolids. Cienc. Investig. Agrar. 2015, 42, 273–283. [Google Scholar] [CrossRef]
  18. Burkart, A. Evolution of Grasses and Grasslands in South America. Taxon 2010, 24, 53–66. [Google Scholar] [CrossRef]
  19. Elorza, M.S.; Ortiz, D.G.; Deltoro, V. La Flora Alóctona de La Comunidad Valenciana (España). Bot. Complut. 2011, 35, 97–130. [Google Scholar] [CrossRef]
  20. Galasso, G.; Conti, F.; Peruzzi, L.; Ardenghi, N.M.G.; Banfi, E.; Celesti-Grapow, L.; Albano, A.; Alessandrini, A.; Bacchetta, G.; Ballelli, S.; et al. An Updated Checklist of the Vascular Flora Alien to Italy. Plant Biosyst. 2018, 152, 556–592. [Google Scholar] [CrossRef]
  21. Molina, J.; González-Orenga, S.; Vicente, O.; Boscaiu, M.; Llinares, J.V.; Zambrano, F.; Santibáñez, C. Effect of Acetylsalicylic Acid and Ammonium Sulphate on Productive and Physiological Parameters in Amelichloa Caudata under Water Shortage Conditions. Not. Bot. Horti Agrobot. Cluj-Napoca 2022, 50, 12645. [Google Scholar] [CrossRef]
  22. Verdugo, C.; Sánchez, P.; Santibáñez, C.; Urrestarazu, P.; Bustamante, E.; Silva, Y.; Gourdon, D.; Ginocchio, R. Efficacy of Lime, Biosolids, and Mycorrhiza for the Phytostabilization of Sulfidic Copper Tailings in Chile: A Greenhouse Experiment. Int. J. Phytoremediation 2011, 13, 107–125. [Google Scholar] [CrossRef]
  23. Weimberg, R. Solute Adjustments in Leaves of Two Species of Wheat at Two Different Stages of Growth in Response to Salinity. Physiol. Plant. 1987, 70, 381–388. [Google Scholar] [CrossRef]
  24. Hodges, D.M.; DeLong, J.M.; Forney, C.F.; Prange, R.K. Improving the Thiobarbituric Acid-Reactive-Substances Assay for Estimating Lipid Peroxidation in Plant Tissues Containing Anthocyanin and Other Interfering Compounds. Planta 1999, 207, 604–611. [Google Scholar] [CrossRef]
  25. Blainski, A.; Lopes, G.C.; De Mello, J.C.P. Application and Analysis of the Folin Ciocalteu Method for the Determination of the Total Phenolic Content from Limonium brasiliense L. Molecules 2013, 18, 6852–6865. [Google Scholar] [CrossRef]
  26. Jia, Z.; Tang, M.; Wu, J. The Determination of Flavonoid Contents in Mulberry and Their Scavenging Effects on Superoxide Radicals. Food Chem. 1999, 64, 555–559. [Google Scholar]
  27. Bates, L.S.; Waldren, R.P.A.; Teare, I.D. Rapid Determination of Free Proline for Water-Stress Studies. Plant Soil 1973, 207, 205–207. [Google Scholar] [CrossRef]
  28. Balzarini, M.G.; Gonzalez, L.A.; Tablada, E.M.; Casanoves, F.; Di Rienzo, J.A.; Robledo, C.W. InfoStat Manual Del Usuario. 2008. Available online: https://www.infostat.com.ar/ (accessed on 20 March 2025).
  29. Khan, M.I.R.; Fatma, M.; Per, T.S.; Anjum, N.A.; Khan, N.A. Salicylic acid-induced abiotic stress tolerance and underlying mechanisms in plants. Front. Plant Sci. 2015, 6, 462. [Google Scholar] [CrossRef]
  30. Khan, M.I.R.; Poor, P.; Janda, T. Salicylic Acid: A Versatile Signaling Molecule in Plants. J. Plant Growth Regul. 2022, 41, 1887–1890. [Google Scholar] [CrossRef]
  31. Kang, G.; Li, G.; Guo, T. Molecular Mechanism of Salicylic Acid-Induced Abiotic Stress Tolerance in Higher Plants. Acta Physiol. Plant. 2014, 36, 2287–2297. [Google Scholar] [CrossRef]
  32. Elsisi, M.; Elshiekh, M.; Sabry, N.; Aziz, M.; Attia, K.; Islam, F.; Chen, J.; Abdelrahman, M. The genetic orchestra of salicylic acid in plant resilience to climate change induced abiotic stress: Critical review. Stress Biol. 2024, 4, 31. [Google Scholar] [CrossRef]
  33. Kang, G.; Li, G.; Xu, W.; Peng, X.; Han, Q.; Zhu, Y.; Guo, T. Proteomics Reveals the Effects of Salicylic Acid on Growth and Tolerance to Subsequent Drought Stress in Wheat. J. Proteome Res. 2012, 11, 6066–6079. [Google Scholar] [CrossRef]
  34. Kang, G.; Li, G.; Zheng, B.; Han, Q.; Wang, C.; Zhu, Y.; Guo, T. Proteomic Analysis on Salicylic Acid-Induced Salt Tolerance in Common Wheat Seedlings (Triticum aestivum L.). Biochim. Biophys. Acta 2012, 1824, 1324–1333. [Google Scholar] [CrossRef]
  35. Wang, H.; Tariq, L.; Yan, Y.; Bi, Y.; Song, F. NAC Transcription Factors Transcriptionally Fine-Tune Signal Homeostasis in Plant Systemic Acquired Resistance. Physiol. Plant. 2025, 177, e70123. [Google Scholar] [CrossRef] [PubMed]
  36. de Oliveira, T.M.; Cidade, L.C.; Gesteira, A.S.; Filho, M.A.C.; Filho, W.S.S.; Costa, M.G.C. Analysis of the NAC Transcription Factor Gene Family in Citrus Reveals a Novel Member Involved in Multiple Abiotic Stress Responses. Tree Genet. Genomes 2011, 7, 1123–1134. [Google Scholar] [CrossRef]
  37. Jin, H.; Huang, F.; Cheng, H.; Song, H.; Yu, D. Overexpression of the GmNAC2 Gene, an NAC Transcription Factor, Reduces Abiotic Stress Tolerance in Tobacco. Plant Mol. Biol. Rep. 2013, 31, 435–442. [Google Scholar] [CrossRef]
  38. Senaratna, T.; Touchell, D.; Bunn, E.; Dixon, K. Acetyl Salicylic Acid (Aspirin) and Salicylic Acid Induce Multiple Stress Tolerance in Bean and Tomato Plants. Plant Growth Regul. 2000, 30, 157–161. [Google Scholar] [CrossRef]
  39. Rihan, H. The Effect of Exogenous Applications of Salicylic Acid and Molybdenum on the Tolerance of Drought in Wheat. Agric. Res. Technol. 2017, 9, 555768. [Google Scholar] [CrossRef]
  40. Hussain, K.; Nawaz, K.; Majeed, A.; Khan, F.; Lin, F.; Ghani, A.; Raza, G.; Afghan, S.; Zia-ul-Hussnain, S.; Ali, K.; et al. Alleviation of Salinity Effects by Exogenous Applications of Salicylic Acid in Pearl Millet (Pennisetum glaucum (L.) R. Br.) Seedlings. Afr. J. Biotechnol. 2010, 9, 8602–8607. [Google Scholar]
  41. Ennajeh, M.; Vadel, A.M.; Cochard, H.; Khemira, H. Comparative Impacts of Water Stress on the Leaf Anatomy of a Drought-Resistant and a Drought-Sensitive Olive Cultivar. J. Hortic. Sci. Biotechnol. 2010, 85, 289–294. [Google Scholar] [CrossRef]
  42. Saska, P.; Skuhrovec, J.; Tylová, E.; Platková, H.; Tuan, S.J.; Hsu, Y.T.; Vítámvás, P. Leaf Structural Traits Rather than Drought Resistance Determine Aphid Performance on Spring Wheat. J. Pest Sci. 2021, 94, 423–434. [Google Scholar] [CrossRef]
  43. Chang, Z.; Zhuo, L.; Yu, F.; Zhang, X. Effects of Biosolids on Root Growth and Nitrogen Metabolism in Kentucky Bluegrass under Drought Stress. HortScience 2014, 49, 1205–1211. [Google Scholar] [CrossRef]
  44. Stavridou, E.; Giannakis, I.; Karamichali, I.; Kamou, N.N.; Lagiotis, G.; Madesis, P.; Emmanouil, C.; Kungolos, A.; Nianiou-obeidat, I.; Lagopodi, A.L. Biosolid-amended Soil Enhances Defense Responses in Tomato Based on Metagenomic Profile and Expression of Pathogenesis-related Genes. Plants 2021, 10, 2789. [Google Scholar] [CrossRef]
  45. Trippe, K.M.; Manning, V.A.; Reardon, C.L.; Klein, A.M.; Weidman, C.; Ducey, T.F.; Johnson, M.G. Phytostabilization of acidic mine tailings with biochar, biosolids, lime, and locally-sourced microbial inoculum: Do amendment mixtures influence plant growth, tailing chemistry, and microbial composition? Appl. Soil Ecol. 2021, 165, 103962. [Google Scholar] [CrossRef] [PubMed]
  46. Pampana, S.; Rossi, A.; Arduini, I. Biosolids Benefit Yield and Nitrogen Uptake in Winter Cereals without Excess Risk of n Leaching. Agronomy 2021, 11, 1482. [Google Scholar] [CrossRef]
  47. Sidhu, H.; O’Connor, G.; Kruse, J. Plant Toxicity and Accumulation of Biosolids-Borne Ciprofloxacin and Azithromycin. Sci. Total Environ. 2019, 648, 1219–1226. [Google Scholar] [CrossRef]
  48. Möller, K.; Müller, T. Effects of Anaerobic Digestion on Digestate Nutrient Availability and Crop Growth: A Review. Eng. Life Sci. 2012, 12, 242–257. [Google Scholar] [CrossRef]
  49. Ondreičková, K.; Piliarová, M.; Klčová, L.; Žofajová, A.; Gubiš, J.; Horník, M.; Gubišová, M.; Hudcovicová, M.; Kraic, J. The Impact of Sewage Sludge on the Fungal Communities in the Rhizosphere and Roots of Barley and on Barley Yield. Open Life Sci. 2021, 16, 210–221. [Google Scholar] [CrossRef] [PubMed]
  50. Gondek, M.; Weindorf, D.C.; Thiel, C.; Kleinheinz, G. Soluble Salts in Compost and Their Effects on Soil and Plants: A Review. Compos. Sci. Util. 2020, 28, 59–75. [Google Scholar] [CrossRef]
  51. Weggler-Beaton, K.; McLaughlin, M.J.; Graham, R.D. Salinity increases cadmium uptake by wheat and Swiss chard from soil amended with biosolids. Soil Res. 2000, 38, 37–46. [Google Scholar] [CrossRef]
  52. Kim, K.R.; Owens, G. Potential for Enhanced Phytoremediation of Landfills Using Biosolids—A Review. J. Environ. Manag. 2010, 91, 791–797. [Google Scholar] [CrossRef]
  53. López-Millán, A.F.; Sagardoy, R.; Solanas, M.; Abadía, A.; Abadía, J. Cadmium Toxicity in Tomato (Lycopersicon esculentum) Plants Grown in Hydroponics. Environ. Exp. Bot. 2009, 65, 376–385. [Google Scholar] [CrossRef]
  54. Jia, Y.; Tang, S.R.; Ju, X.H.; Shu, L.N.; Tu, S.X.; Feng, R.W.; Giusti, L. Effects of Elevated CO2 Levels on Root Morphological Traits and Cd Uptakes of Two Lolium Species under Cd Stress. J. Zhejiang Univ. Sci. B. 2011, 12, 313–325. [Google Scholar] [CrossRef]
  55. Muranaka, S.; Shimizu, K.; Kato, M. A salt-tolerant cultivar of wheat maintains photosynthetic activity by suppressing sodium uptake. Photosynthetica 2002, 40, 505–515. [Google Scholar]
  56. Brini, F.; Hanin, M.; Mezghani, I.; Berkowitz, G.A.; Masmoudi, K. Overexpression of Wheat Na+/H+ Antiporter TNHX1 and H+-Pyrophosphatase TVP1 Improve Salt- and Drought-Stress Tolerance in Arabidopsis thaliana Plants. J. Exp. Bot. 2007, 58, 301–308. [Google Scholar] [CrossRef]
  57. Dugasa, M.T.; Cao, F.; Ibrahim, W.; Wu, F. Differences in Physiological and Biochemical Characteristics in Response to Single and Combined Drought and Salinity Stresses between Wheat Genotypes Differing in Salt Tolerance. Physiol. Plant 2019, 165, 134–143. [Google Scholar] [CrossRef]
  58. Noreen, S.; Fatima, K.; Athar, H.U.R.; Ahmad, S.; Hussain, K. Enhancement of Physio-Biochemical Parameters of Wheat through Exogenous Application of Salicylic Acid under Drought Stress. J. Anim. Plant Sci. 2017, 27, 153–163. [Google Scholar]
  59. Kaydan, D.; Yagmur, M.; Okut, N. Effects of Salicylic Acid on the Growth and Some Physiological Characters in Salt Stressed Wheat (Triticum aestivum L.). Tarım Bilim. Der. 2007, 13, 1. [Google Scholar] [CrossRef]
  60. Jini, D.; Joseph, B. Physiological Mechanism of Salicylic Acid for Alleviation of Salt Stress in Rice. Rice Sci. 2017, 24, 97–108. [Google Scholar] [CrossRef]
  61. Yang, D.; Ni, R.; Yang, S.; Pu, Y.; Qian, M.; Yang, Y.; Yang, Y. Functional Characterization of the Amelichloa purpurea P5cs Gene under Drought Stress Conditions. Int. J. Mol. Sci. 2021, 22, 9599. [Google Scholar] [CrossRef]
  62. Gunes, A.; Inal, A.; Alpaslan, M.; Cicek, N.; Guneri, E.; Eraslan, F.; Guzelordu, T. Effects of Exogenously Applied Salicylic Acid on the Induction of Multiple Stress Tolerance and Mineral Nutrition in Maize (Zea mays L.). Arch. Agron. Soil Sci. 2005, 51, 687–695. [Google Scholar] [CrossRef]
  63. Aldesuquy, H.S.; Abbas, M.A.; Abo-Hamed, S.A.; Elhakem, A.H. Does Glycine Betaine and Salicylic Acid Ameliorate the Negative Effect of Drought on Wheat by Regulating Osmotic Adjustment through Solutes Accumulation? Furthermore, osmotic. J. Plant Stress Physiol. 2013, 9, 5–22. [Google Scholar]
  64. Garg, N.; Chandel, S. Role of Arbuscular Mycorrhizal (AM) Fungi on Growth, Cadmium Uptake, Osmolyte, and Phytochelatin Synthesis in Cajanus cajan (L.) Millsp. Under NaCl and Cd Stresses. J. Plant Growth Regul. 2012, 31, 292–308. [Google Scholar] [CrossRef]
  65. Ziadi, N.; Gagnon, B.; Nyiraneza, J. Crop Yield and Soil Fertility as Affected by Papermill Biosolids and Liming By-Products. Can. J. Soil Sci. 2013, 93, 319–328. [Google Scholar] [CrossRef]
  66. Maftoun, M.; Moshiri, F.; Karimian, N.; Ronaghi, A.M. Effects of Two Organic Wastes in Combination with Phosphorus on Growth and Chemical Composition of Spinach and Soil Properties. J. Plant Nutr. 2004, 27, 1635–1651. [Google Scholar] [CrossRef]
  67. Singh, M.; Kumar, J.; Singh, S.; Singh, V.P.; Prasad, S.M. Roles of Osmoprotectants in Improving Salinity and Drought Tolerance in Plants: A Review. Rev. Environ. Sci. Biotechnol. 2015, 14, 407–426. [Google Scholar] [CrossRef]
  68. Marschner, H. Mineral Nutrition of Higher Plants, 2nd ed.; Elsevier: Amsterdam, The Netherlands, 1995; ISBN 978-0-12-473542-2. [Google Scholar]
  69. Chen, H.; Yan, S.; Ye, Z.; Meng, H.; Zhu, Y. Utilization of Urban Sewage Sludge: Chinese Perspectives. Environ. Sci. Pollut. Res. 2012, 19, 1454–1463. [Google Scholar] [CrossRef]
  70. Torri, S.I.; Corrêa, R.S.; Renella, G. Soil Carbon Sequestration Resulting from Biosolids Application. Appl. Environ. Soil Sci. 2014, 2014, 821768. [Google Scholar] [CrossRef]
  71. Rajala, A. Plant Growth Regulators to Manipulate Oat Stands. Agric. Food Sci. 2004, 13, 186–197. [Google Scholar] [CrossRef]
  72. Brown, J.C.; Tiffin, L.O.; Holmes, R.S. Competition between chelating agents and roots as factor affecting absorption of iron and other ions by plant species. Plant Physiol. 1960, 35, 878. [Google Scholar] [CrossRef]
  73. Patel, J.A.; Vora, A.B. Free Proline Accumulation in Drought-Stressed Plants. Plant Soil 1985, 84, 427–429. [Google Scholar] [CrossRef]
  74. Johari-Pireivatlou, M.; Qasimov, N.; Maralian, H. Effect of Soil Water Stress on Yield and Proline Content of Four Wheat Lines. Afr. J. Biotechnol. 2010, 9, 036–040. [Google Scholar]
  75. Al Hassan, M.; López-Gresa, M.D.P.; Boscaiu, M.; Vicente, O. Stress Tolerance Mechanisms in Juncus: Responses to Salinity and Drought in Three Juncus Species Adapted to Different Natural Environments. Funct. Plant Biol. 2016, 43, 949–960. [Google Scholar] [CrossRef]
  76. Lee, B.R.; Islam, M.T.; Park, S.H.; Jung, H.I.; Bae, D.W.; Kim, T.H. Characterization of Salicylic Acid-mediated Modulation of the Drought Stress Responses: Reactive Oxygen Species, Proline, and Redox State in Brassica napus. Env. Exp. Bot. 2019, 157, 10. [Google Scholar] [CrossRef]
  77. Szabados, L.; Savouré, A. Proline: A multifunctional Amino Acid. Trends Plant Sci. 2010, 15, 89–97. [Google Scholar] [CrossRef]
  78. Maghsoudi, K.; Emam, Y.; Niazi, A.; Pessarakli, M.; Arvin, M.J. P5CS Expression Level and Proline Accumulation in the Sensitive and Tolerant Wheat Cultivars under Control and Drought Stress Conditions in the Presence/Absence of Silicon and Salicylic Acid. J. Plant Interact. 2018, 13, 461–471. [Google Scholar] [CrossRef]
  79. Ignatenko, A.; Talanova, V.; Repkina, N.; Titov, A. Exogenous Salicylic Acid Treatment Induces Cold Tolerance in Wheat through Promotion of Antioxidant Enzyme Activity and Proline Accumulation. Acta Physiol. Plant 2019, 41, 80. [Google Scholar] [CrossRef]
  80. Gill, S.S.; Tuteja, N. Reactive Oxygen Species and Antioxidant Machinery in Abiotic Stress Tolerance in Crop Plants. Plant Physiol. Biochem. 2010, 48, 909–930. [Google Scholar] [CrossRef]
  81. Wang, H.; Zhang, L.; Ma, J.; Li, X.-Y.; Li, Y.; Zhang, R.; Wang, R. Effects of Water Stress on Reactive Oxygen Species Generation and Protection System in Rice During Grain-Filling Stage. Agric. Sci. China 2010, 9, 633–641. [Google Scholar] [CrossRef]
  82. Shan, C.; Wang, B.; Sun, H.; Gao, S.; Li, H. H2S Induces No in the Regulation of AsA-GSH Cycle in Wheat Seedlings by Water Stress. Protoplasma 2020, 257, 1487–1493. [Google Scholar] [CrossRef]
  83. Mahouachi, J.; Argamasilla, R.; Gómez-Cadenas, A. Influence of Exogenous Glycine Betaine and Abscisic Acid on Papaya in Responses to Water-Deficit Stress. J. Plant Growth Regul. 2012, 31, 1–10. [Google Scholar] [CrossRef]
  84. Saruhan, N.; Saglam, A.; Kadioglu, A. Salicylic Acid Pretreatment Induces Drought Tolerance and Delays Leaf Rolling by Inducing Antioxidant Systems in Maize Genotypes. Acta Physiol. Plant. 2012, 34, 97–106. [Google Scholar] [CrossRef]
  85. La, V.H.; Lee, B.R.; Zhang, Q.; Park, S.H.; Islam, M.T.; Kim, T.H. Salicylic Acid Improves Drought-Stress Tolerance by Regulating the Redox Status and Proline Metabolism in Brassica rapa. Hortic. Environ. Biote. 2019, 60, 31–40. [Google Scholar] [CrossRef]
  86. Rai, G.K.; Magotra, I.; Khanday, D.M.; Choudhary, S.M.; Bhatt, A.; Gupta, V.; Rai, P.K.; Kumar, P. Boosting Drought Tolerance in Tomatoes through Stimulatory Action of Salicylic Acid Imparted Antioxidant Defense Mechanisms. Agronomy 2024, 14, 1227. [Google Scholar] [CrossRef]
  87. Zhang, X.; Zhou, D.; Ervin, E.H.; Evanylo, G.K.; Cataldi, D.; Li, J. Biosolids Impact Antioxidant Metabolism Associated with Drought Tolerance in Tall Fescue. HortScience 2012, 47, 1550–1555. [Google Scholar] [CrossRef]
  88. Mkhinini, M.; Helaoui, S.; Boughattas, I.; Amemou, C.; Banni, M. Earthworm Eisenia andrei Modulates Oxidative Stress in Bean Plants Vicia faba Irrigated with Treated Wastewater. Ecotoxicology 2020, 29, 1003–1016. [Google Scholar] [CrossRef]
  89. Marchuk, S.; Tait, S.; Sinha, P.; Harris, P.; Antille, D.L.; McCabe, B.K. Biosolids-derived fertilisers: A review of challenges and opportunities. Sci. Total Environ. 2023, 875, 162555. [Google Scholar] [CrossRef] [PubMed]
  90. Hu, Y.; Pang, S.; Yang, J.; Zhao, X.; Cao, J. Changes in soil microbial community structure following amendment of biosolids for seven years. Environ. Pollut. Bioavailab. 2019, 31, 24–31. [Google Scholar] [CrossRef]
Agronomy 15 00785 g001aAgronomy 15 00785 g001b
Figure 1. Shoot length for treatments (A) and water status (B). Leaf width for treatments (C) and water status (D). Leaf thickness for treatments (A) and water status (B). Leaf thickness for treatments (E), and water status (F). Different letters indicate significant differences based on Fisher’s test (p-value < 0.05). Vertical bars represent mean ± standard error. ASA = acetylsalicylic acid; BS = biosolids; Control. Irrigated; WR = water-restricted.
Figure 1. Shoot length for treatments (A) and water status (B). Leaf width for treatments (C) and water status (D). Leaf thickness for treatments (A) and water status (B). Leaf thickness for treatments (E), and water status (F). Different letters indicate significant differences based on Fisher’s test (p-value < 0.05). Vertical bars represent mean ± standard error. ASA = acetylsalicylic acid; BS = biosolids; Control. Irrigated; WR = water-restricted.
Agronomy 15 00785 g001aAgronomy 15 00785 g001b
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Figure 2. Leaf fresh weight for treatments (A) and water status (B). Leaf dry weight for treatments (C) and water status (D). Different letters indicate significant differences according to Fisher’s test (p-value < 0.05). Vertical bars indicate mean ± standard error. ASA = acetylsalicylic acid; BS = biosolids; Control. Irrigated; WR = water-restricted.
Figure 2. Leaf fresh weight for treatments (A) and water status (B). Leaf dry weight for treatments (C) and water status (D). Different letters indicate significant differences according to Fisher’s test (p-value < 0.05). Vertical bars indicate mean ± standard error. ASA = acetylsalicylic acid; BS = biosolids; Control. Irrigated; WR = water-restricted.
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Figure 3. Root fresh weight for treatments (A) and root dry weight for interaction of the factors treatments and water status (B). Different letters indicate significant differences according to Fisher’s test (p-value < 0.05). Vertical bars indicate means ± standard error. ASA = acetylsalicylic acid; BS = biosolids; Control = control.
Figure 3. Root fresh weight for treatments (A) and root dry weight for interaction of the factors treatments and water status (B). Different letters indicate significant differences according to Fisher’s test (p-value < 0.05). Vertical bars indicate means ± standard error. ASA = acetylsalicylic acid; BS = biosolids; Control = control.
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Figure 4. Soil solution pH for treatments (A) and water status (B). Electrical conductivity for treatments (C) and water status (D). Different letters indicate significant differences according to Fisher’s test (p-value < 0.05). Vertical bars indicate means ± standard error. ASA = acetylsalicylic acid; BS = biosolids; Control. Irrigated; WR = water-restricted.
Figure 4. Soil solution pH for treatments (A) and water status (B). Electrical conductivity for treatments (C) and water status (D). Different letters indicate significant differences according to Fisher’s test (p-value < 0.05). Vertical bars indicate means ± standard error. ASA = acetylsalicylic acid; BS = biosolids; Control. Irrigated; WR = water-restricted.
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Figure 5. Volumetric water content in soil for the factors treatments (A) and water status (B). Different letters indicate significant differences according to Fisher’s test (p-value < 0.05). Vertical bars indicate means ± standard error. ASA = acetylsalicylic acid; BS = biosolids; Control. Irrigated; WR = water-restricted.
Figure 5. Volumetric water content in soil for the factors treatments (A) and water status (B). Different letters indicate significant differences according to Fisher’s test (p-value < 0.05). Vertical bars indicate means ± standard error. ASA = acetylsalicylic acid; BS = biosolids; Control. Irrigated; WR = water-restricted.
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Figure 6. Root Na+ interaction (A), between factors (A) and factor water status (B). Root Cl− interaction (B) between factors (A) and factor water status (B). Different letters indicate significant differences according to Fisher’s test (p-value < 0.05). Vertical bars indicate means ± standard error. ASA = acetylsalicylic acid; BS = biosolids; Control.
Figure 6. Root Na+ interaction (A), between factors (A) and factor water status (B). Root Cl− interaction (B) between factors (A) and factor water status (B). Different letters indicate significant differences according to Fisher’s test (p-value < 0.05). Vertical bars indicate means ± standard error. ASA = acetylsalicylic acid; BS = biosolids; Control.
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Figure 7. Pro content in leaves for treatments (A) and water status (B). Different letters indicate significant differences according to Fisher’s test (p-value < 0.05). Vertical bars indicate means ± standard error. Irrigated; WR = water-restricted.
Figure 7. Pro content in leaves for treatments (A) and water status (B). Different letters indicate significant differences according to Fisher’s test (p-value < 0.05). Vertical bars indicate means ± standard error. Irrigated; WR = water-restricted.
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Figure 8. Significant differences for MDA in leaves for treatments (A) and water status (B) factors. Different letters indicate means ± significant differences according to Fisher’s test (p-value < 0.05). Vertical bars indicate standard error. ASA = acetylsalicylic acid; BS = biosolids; Control. Irrigated; WR = water-restricted.
Figure 8. Significant differences for MDA in leaves for treatments (A) and water status (B) factors. Different letters indicate means ± significant differences according to Fisher’s test (p-value < 0.05). Vertical bars indicate standard error. ASA = acetylsalicylic acid; BS = biosolids; Control. Irrigated; WR = water-restricted.
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Table 1. The experimental design used in the experiment. Irrigated; WR = water-restricted. Abbreviations: T1 = ASA/BS; T2 = ASA; T3 = BS; T4 = Control.
Table 1. The experimental design used in the experiment. Irrigated; WR = water-restricted. Abbreviations: T1 = ASA/BS; T2 = ASA; T3 = BS; T4 = Control.
Block 1Block 2Block 3Block 4
IrrigatedWRIrrigatedWRIrrigatedWRIrrigatedWR
T4T2T1T3T2T3T4T2
T1T3T2T1T1T1T1T4
T2T1T4T4T3T2T2T1
T3T4T3T2T4T4T3T3
Table 2. Na+, Cl− and K+ contents in roots for treatments (A), water status (B) and A × B interaction factors. ASA = acetylsalicylic acid; BS = biosolids; Control; Irrigated; WR = water-restricted. Means ± standard error. *** Indicates significant differences according to Fisher’s test (p-value <0.001); n.s = Not significant.
Table 2. Na+, Cl− and K+ contents in roots for treatments (A), water status (B) and A × B interaction factors. ASA = acetylsalicylic acid; BS = biosolids; Control; Irrigated; WR = water-restricted. Means ± standard error. *** Indicates significant differences according to Fisher’s test (p-value <0.001); n.s = Not significant.
Water StatusTreatmentsNa+ (µmol g−1 DW−1).Cl− (µmol g−1 DW−1)K+ (µmol g−1 DW−1)
IrrigatedASA + BS331.12 ± 17.89 109.76 ± 18.45 130.34 ± 10.71
ASA115.52 ± 17.89 141.47 ± 15.97 136.24 ± 10.71
BS164.50 ± 17.89 139.35 ± 15.97 191.08 ± 55.53
Control108.08 ± 17.89 165.44 ± 15.97 195.05 ± 55.53
WRASA + BS72.63 ± 17.89 77.56 ± 15.97 120.49 ± 9.78
ASA82.68 ± 17.89 189.33 ± 15.97 124.46 ± 9.78
BS78.71 ± 20.65 57.54 ± 15.97 127.30 ± 41.42
Control93.21 ± 17.89 163.05 ± 15.97 123.28 ± 41.42
Treatments (A) ******n.s
Water Status (B) ***n.sn.s
Interaction A × B ******n.s
Table 3. Total phenolic compounds (TFC), total flavonoids (TF), proline (Pro) and malondialdehyde (MDA) contents in leaves with respect to the factors treatments (A), water status (B) and A × B interaction. ASA = acetylsalicylic acid; BS = biosolids; Control; Irrigated; WR = water-restricted. Means ± standard error. *, **, *** indicate significant at p < 0.05, p < 0.01, or p < 0.001, respectively according to Fisher’s test; n.s = Not significant.
Table 3. Total phenolic compounds (TFC), total flavonoids (TF), proline (Pro) and malondialdehyde (MDA) contents in leaves with respect to the factors treatments (A), water status (B) and A × B interaction. ASA = acetylsalicylic acid; BS = biosolids; Control; Irrigated; WR = water-restricted. Means ± standard error. *, **, *** indicate significant at p < 0.05, p < 0.01, or p < 0.001, respectively according to Fisher’s test; n.s = Not significant.
Water ConditionTreatmentsTFC (mg eq. GA g−1 DW)TF (catequin g−1 DW)Pro (µmol g−1 DW−1)MDA (nmol g−1 DW−1)
ASA + BS71.64 ± 13.233.53 ± 0.129.31 ± 4.4081.60 ± 8.72
IrrigatedASA67.12 ± 9.163.28 ± 0.118.89 ± 4.4047.87 ± 8.72
BS82.09 ± 13.233.73 ± 0.12 8.78 ± 4.406.26 ± 8.72
Control75.10 ± 13.233.01 ± 0.1210.95 ± 4.4037.79 ± 8.72
ASA + BS56.89 ± 16.012.85 ± 0.7522.25 ± 5.4541.65 ± 7.55
WRASA56.83 ± 9.162.60 ± 0.5331.70 ± 5.87 26.10 ± 7.55
BS57.92 ± 16.012.88 ± 0.7525.09 ± 4.9144.99 ± 10.68
Control57.88 ± 11.592.40 ± 0.5330.03 ± 7.1330.05 ± 7.55
Treatments (A) n.sn.sn.s **
Water Condition (B) n.sn.s****
Interaction A × B n.sn.sn.sn.s
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MDPI and ACS Style

Molina, J.; Silva-Romano, F.; Morar, I.M.; Boscaiu, M.; Santibáñez, C.; Llinares, J.V. Effects of Acetylsalicylic Acid and Biosolids on Edaphic, Vegetative and Biochemical Parameters of Amelichloa caudata Under Water Shortage Conditions. Agronomy 2025, 15, 785. https://doi.org/10.3390/agronomy15040785

AMA Style

Molina J, Silva-Romano F, Morar IM, Boscaiu M, Santibáñez C, Llinares JV. Effects of Acetylsalicylic Acid and Biosolids on Edaphic, Vegetative and Biochemical Parameters of Amelichloa caudata Under Water Shortage Conditions. Agronomy. 2025; 15(4):785. https://doi.org/10.3390/agronomy15040785

Chicago/Turabian Style

Molina, Julio, Fernando Silva-Romano, Irina M. Morar, Monica Boscaiu, Claudia Santibáñez, and Josep V. Llinares. 2025. "Effects of Acetylsalicylic Acid and Biosolids on Edaphic, Vegetative and Biochemical Parameters of Amelichloa caudata Under Water Shortage Conditions" Agronomy 15, no. 4: 785. https://doi.org/10.3390/agronomy15040785

APA Style

Molina, J., Silva-Romano, F., Morar, I. M., Boscaiu, M., Santibáñez, C., & Llinares, J. V. (2025). Effects of Acetylsalicylic Acid and Biosolids on Edaphic, Vegetative and Biochemical Parameters of Amelichloa caudata Under Water Shortage Conditions. Agronomy, 15(4), 785. https://doi.org/10.3390/agronomy15040785

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