Mitigating salinity stress in Moringa oleifera through seaweed-derived biostimulants

Abstract

Climate change, food scarcity, salt stress, and a rapidly growing population are just a few of the significant global challenges. In arid and semi-arid regions worldwide, salt stress is a significant negative factor that can reduce seed germination and seedling growth, ultimately leading to decreased plant growth and crop productivity. Seaweed extracts are used as nutrient supplements or biofertilizers in agriculture to increase plant growth and yield. In this study, we examined the beneficial effects of foliar applications of seaweed extracts from Turbinaria ornata and Actinotrichia fragilis on the growth and performance of Moringa oleifera under salt stress (up to 300 mM) in a greenhouse. Exposure of Moringa to salinity stress resulted in an overall decrease in growth and the contents of chlorophyll a, chlorophyll b, carotenoids, and soluble sugars, versus an increase in phenolic content. However, foliar application of A. fragilis and T. ornata extracts significantly improved the growth and physiology of Moringa under salt stress, with T. ornata exhibiting greater effectiveness. This study demonstrates that seaweed-based biofertilizers can enhance plant productivity while reducing reliance on chemical inputs, offering a sustainable and environmentally friendly alternative for agriculture.

Supplementary Information

The online version contains supplementary material available at 10.1038/s41598-026-51052-6.

Introduction

Moringa oleifera Lam. (MO) is one of the 13 species of the Moringa genus that belongs to the Moringaceae family¹. Moringa can be used as a vegetable and as an herbal medicine because it is rich in antioxidants, such as ascorbic acid and tocopherols (vitamin E), as well as mineral nutrients^2,3. As illustrated in many research studies, leaves and seeds have the most pharmaceutical potential, as well as nutritional and medicinal benefits. All parts of the tree are rich in nutrients that can be harnessed to address food and nutritional challenges in developing nations worldwide⁴.

In addition to being high in protein, vitamins, oils, fatty acids, micro- and macro-mineral elements, and phenolics⁵, Moringa oleifera is reported to have anti-inflammatory, antimicrobial, antioxidant, anticancer, cardiovascular protective, hepatoprotective, anti-ulcer, diuretic, anti-urolithiatic, and anthelmintic properties. Its numerous pharmaceutical effects are capitalized as a therapeutic remedy for various diseases in the traditional medical system⁶.

Salinity stress can significantly reduce crop yields, particularly in arid and semi-arid areas. In arid regions, crops grow on low-quality soil deficient in major nutrients, under severe conditions such as high temperatures, water deficit, and sometimes both stresses. Soil deterioration occurred due to the overuse of chemical fertilizers, leading to accumulation of excess salt through evaporation, particularly after ineffective irrigation^7–9.

Abiotic stress, such as salinity stress, plays a crucial role in limiting crop efficiency and negatively impacting plant yield potential⁹. Salt stress is one of the significant environmental stresses that affects plant growth and development by altering various physiological processes, including photosynthesis, transpiration, osmotic regulation, the antioxidant system, as well as solute and/or water uptake^9–11.

Seaweed extracts have been reported to benefit plants by promoting early seed germination, enhancing plant growth, improving crop yield, and protecting against biotic and abiotic stresses. They are naturally rich in plant growth-promoting factors, including microelements, organic matter, vitamins, and fatty acids. They can serve as a low-cost alternative to conventional NPK fertilizers and expensive organic farming techniques¹².

Abiotic stress often weakens plant defenses, making plants more susceptible to insects, pests, and pathogens. The interaction between abiotic and biotic stresses can further increase plant vulnerability¹³. Many crop plants are susceptible to cell damage caused by high salinity and can only survive with reduced yields. That’s why this study was undertaken to test the effects of seaweed extracts from Turbinaria ornata and Actinotrichia fragilis on the germination behavior of Moringa oleifera Lam. cultivars under salt stress. Future research will focus on salt stress tolerance signaling networks and on gene expression changes in seaweed extracts. These approaches will reveal cellular and molecular pathways, enabling the development of targeted biostimulants.

Materials and methods

Seaweed sampling and preparation of extracts

Seaweeds Turbinaria ornata and Actinotrichia fragilis used in the present study (Fig. 1) were collected from the coastal area of Hurghada, Egypt, during July 2023. Algal fronds were placed in polythene bags and transported to the laboratory, where they were thoroughly washed with tap water to remove salt¹⁴, shade-dried for 4 days, and then oven-dried for 12 h at 60 °C. Then, the oven-dried fronds were hand-crushed into a coarse powder, which was subsequently extracted with distilled water at 120 °C for 30 min in a 1:20 (w/v) ratio using a pressurized system (autoclave), allowing efficient recovery of water-soluble constituents. This yielded a 5% algal extract, which was considered the stock extract.. The hot extracts were filtered through a double-layered cheesecloth and allowed to cool at room temperature. The resulting supernatant was taken as the stock seaweed extract . Seaweed liquid extracts were prepared at a concentration of 1.0%, obtained by diluting the stock extract fivefold¹⁵.

Fig. 1.

The seaweeds collected from the Red Sea: (A) Turbinaria ornata, and (B) Actinotrichia fragilis.

Physico-chemical and biochemical analysis of seaweed extracts

The pH of the seaweed extracts was measured using a CyberScan PH 510 pH meter. Calcium, potassium, magnesium, zinc, and sodium contents were determined using an atomic absorption spectrophotometer (PerkinElmer AAnalyst 400) following the method described by Alwaleed¹⁴.

Gas chromatography-mass spectrometry (GC–MS) analysis

The chemical composition of seaweed extracts was performed using a Trace GC-TSQ mass spectrometer (Thermo Scientific, Austin, TX, USA) with a direct capillary column TG–5MS (30 m × 0.25 mm × 0.25 µm film thickness). The column oven temperature was initially maintained at 50 °C and then increased by 5 °C/min to 250 °C, where it was held for 2 min. The temperature was then raised to 300 °C at a rate of 30 °C per minute and maintained for two minutes. The injector and MS transfer line temperatures were maintained at 270 °C and 260 °C, respectively. Helium was used as the carrier gas at a constant flow rate of 1 mL/min. The components were identified by comparing their mass spectra with those of the WILEY 09 and NIST 14 mass spectral databases.

Seed material

Seeds of M. oliefera Lam. were obtained from the Agriculture Research Centre, Ministry of Agriculture, Giza, Egypt. Homogenous seeds were sown in the Botanical Garden, Botany and Microbiology Department, Faculty of Science, Qena University.

Germination experiment

A preliminary germination experiment was conducted in the laboratory to observe the effects of sodium chloride salinity (0, 100, 200, and 300 mM NaCl), with or without seaweed liquid extract, on the germination and early seedling growth of Moringa oleifera. This experiment was purely observational, aimed at identifying general trends in response to salt stress and the potential influence of seaweed extract. No quantitative germination parameters or statistical analyses were performed.

Greenhouse experiment

The experiment was carried out at the Faculty of Science, Qena University, Egypt. Uniform moringa seeds were surface sterilized in 0.1% HgCl₂ for 2 min, then rinsed several times with distilled water. An equal number of seeds (10 seeds per pot) were sown in plastic pots (30 cm diameter) filled with mixed, air-dried sand and clay (1:1). The experiment was set up in a completely randomized design with three replicates. Seed germination and plant growth were allowed under suitable conditions of temperature, light, and humidity. Ten days after emergence, five healthy and uniform seedlings were selected from each pot, and the salinity treatment began. Salinity levels included 0, 100, 200, and 300 mM NaCl. Seaweed extracts of T. ornata and A. fragilis at a concentration of 1% were applied in excess to the foliage twice weekly. Seeds grown without seaweed extract applications served as the non-amended control to evaluate treatment efficiency; the control plants were sprayed with distilled water alone under the same conditions used for the seaweed extract treatments. After 30 days of the salinity treatment, plants were harvested for assay of growth and the physiological and biochemical responses.

Assay of plant growth and pigment content

Immediately after harvesting, plants were separated into shoots and roots, and fresh weights were recorded. The roots and shoots were dried in an oven at 80 °C for 48 h to attain dry weight. The method described by Lichtenthaler¹⁶ was used to measure photosynthetic pigments in fresh leaves. Fresh leaf tissue (0.1 g) was homogenized in 10 mL of 80% (v/v) acetone and centrifuged at 3000 rpm for 10 min. The supernatant was collected, and the absorbance was measured using a UV–vis spectrophotometer at 663 nm, 646 nm, and 470 nm.

Assay of soluble carbohydrates and phenolic compounds

The soluble sugar content of leaves and roots was estimated using the method of Dubois et al.¹⁷, and phenolic compounds of leaves were measured according to the method of Škerget et al.¹⁸ using the Folin–Ciocalteu reagent.

Statistical analysis

The data were analyzed statistically to assess the effects of salinity, algal amendment, and their interaction on M. oleifera growth and performance. A two-way analysis of variance (ANOVA) was performed using SPSS. Differences were considered statistically significant at P < 0.05. All measurements were estimated in triplicate (n = 3), and data are presented as mean ± standard deviation (SD). Different letters above bars indicate significant differences among treatments at P  <0.05. A color heat map analysis of growth and physiological responses of Moringa oleifera to salinity stress and SWE applications was produced using the web tool ClustVis.

Results and discussion

Table 1 shows the physicochemical composition of the seaweed extracts assayed in this study. The pH of the T. ornata and A. fragilis extracts (6.8 and 7.2, respectively) was almost neutral.

Table 1.

Physicochemical properties of the seaweed extracts.

Characteristic	Turbinaria ornata	Actinotrichia fragilis
Taxonomic group	Phaeophyta	Rhodophyta
pH	6.8	7.2
Magnesium (% DW)	2.79 ± 0.4	1.11 ± 0.1
Calcium (% DW)	51.48 ± 7.1	67.68 ± 8.5
Sodium (% DW)	3.29 ± 0.9	1.04 ± 0.1
Potassium (% DW)	9.00 ± 1.1	0.57 ± 0.01
Zinc (mg/kg DW)	93.28 ± 5.7	255 ± 15.5

The mineral composition of algal extracts showed that T. ornata extract was characterized by higher contents of Mg (2.79%), Na ( 3.29%), and K (9.0%), but lower contents of Ca (51.5%) and Zn (93.3 mg/kg DW) compared with A. fragilis extract, which contained Mg, Na, K, and Ca contents of 1.11%, 1.04%, 0.57%, and 67.7%, respectively, and Zn content of 255 mg/kg DW. Based on our analysis, the two experimental seaweeds contain substantial levels of several macro- and micronutrients, which justify their use as plant biofertilizers. Previous studies have demonstrated that seaweed extracts can be applied to soil and plants, resulting in superior performance compared to conventional chemical fertilizers¹⁹.

The fractionation of organic components of algal extracts was documented by Gas Chromatography-Mass Spectrometry (GC–MS). Fifteen compounds were identified in A. fragilis and twenty-five in T. ornata, which can contribute to the nutritional quality of the seaweed extract. The major compounds were Hexadecenoic acid (20.21%), Oleic Acid (11.26%), and Trilinolein (18.14%). Trilinolein has been reported to possess antioxidant properties²⁰. The chemical constituents identified in the extracts of T. ornata and A. fragilis, presented in Fig. 2 and Tables 2 and 3, are Valerena-4,7(11)-diene as the major component, followed by Hexadecadienal in T. ornata and palmitic acid and Trilinolein in A. fragilis. The investigation of T. ornata and A. fragilis extracts confirmed the presence of certain phytochemicals, as reported by Abdel Latef¹⁵. These compounds, such as Octadecanoic acid, Oleic Acid, Palmitoleic acid, and Ascorbyl palmitate, exhibit broad-spectrum antimicrobial activity. To control plant stress, these seaweed extracts were investigated as fertilizer supplements²¹.

Fig. 2.

GC/MS chromatogram of A. fragilis (A) and T. ornata (B) extracts.

Table 2.

GC–MS of phytochemical compounds of A. fragilis extract.

RT, Retention time; MF, Molecular formula; MW, Molecular weight.

Table 3.

GC–MS of phytochemical compounds of T. ornata extracts.

RT, Retention time; MF, Molecular formula; MW, Molecular weight

Increasing salinity led to a progressive reduction in plant growth. In non-amended plants, the reductions in shoot fresh weight, root fresh weight, shoot dry weight, and root dry weight under 200 mM NaCl were 55.7%, 76.2%, 64.1%, and 92.2%, respectively, below with the control.In algal-amended plants, the salinity-induced growth reduction was less severe. It amounted to 11.7%, 25%, 57.2% and 60.6% for shoot and root fresh weights, shoot and root dry weights, respectively in T. ornata-amended plants, and to 27.9%, 45.4%, 57% and 73%, respectively in A. fragilis -amended plants (Fig. 3). By contrast, amendment with algal extracts significantly enhanced plant growth and the improvement was most evident due to T. ornata under salinity stress. The improvement in shoot fresh weight, root fresh weight, shoot dry weight and root dry weight due to T. ornata extract amounted to 48.8%, 74.8%, 126% and 108%, respectively above non-amended plants in absence of salinity and to 197%, 450%, 170% and 950%, respectively under the impact of 200 mM NaCl; meanwhile the improvement due to A. fragilis extract amounted to 30.3%, 72.2%, 94.6% and 97.4%, respectively in absence of salinity and to 112%, 294%, 133% and 580%, respectively under the impact of 200 mM NaCl (Fig. 3). Thus, the detrimental effect of salinity on moringa growth was more severe on root growth than shoot growth, which will lead to decreased root to shoot dry weight ratio. In fact, in non-amended plants, root growth ceased completely under 300 mM NaCl, whereas shoot growth remained appreciable. Likewise, the beneficial effect of algal amendments was more pronounced for roots than shoots, and under the impact of salinity than in its absence.

Fig. 3.

Effect of salinity on fresh weights and dry weights of shoot and root of Moringa oleifera seedlings amended with extracts of the seaweeds T. ornata and A. fragilis. Each column represents the mean ± SE (n = 3Means followed by the same letters are non-significantly different at P < 0.05.

Algal amendment (Amend) had a highly significant impact onplant growth (P < 0.001). Similarly, the salinity × Amendment interaction showed a highly significant effect on all growth traits (P < 0.001), indicating that the impact of algal extracts depends on the salinity level, as presented in Supplementary Table S1.

The reduction in plant growth and yield under salt stress has been reported in numerous studies^3,26,27 due to disturbances in plant physiological and biochemical processes. Salinity has both osmotic and specific ion effects on growth²⁸. The osmotic effect of NaCl is the consequence of the lowered water potential of the medium which results in decreased water availability. The accumulation of salt ions (Na⁺ and Cl^-) in plant tissues negatively affects plant metabolism. and suppresses the uptake of essential nutrients, such as phosphorus (P) and potassium (K)²⁹.

Seaweedscontain macro- and micro-nutrients, amino acids, vitamins, cytokinins, auxins, and abscisic acid, which affect cellular metabolism in treated plants, leading to enhanced growth¹⁴. In addition, seaweeds contain precursors of elicitor compounds that promote seed germination³⁰. Another explanation for the beneficial effect of seaweed for plants is that the occurrence of seaweed polysaccharides can improve growth in a way similar to growth hormones³¹. Several mechanisms have been proposed to explain plant survival under salinity stress. Exogenous protectants, such as seaweed extracts, are effective in mitigating the deleterious effects of salinity on plant growth. The use of seaweed priming to enhance environmental stress tolerance has been gaining traction in agricultural production due to its unique bioactive compounds^32,33.

The improvement in shoot characteristics might be due to the auxin content in the seaweed extracts, which has an effective role in cell division and enlargement. This positive effect might also be due to the macronutrients N, K, and P, as well as the micronutrients Zn, Cu, and B in the seaweed extracts, which play significant roles in biochemical activities and plant growth and development^34,35. A reduction in shoot and root growth of moringa was observed under the impact of salinity stress, but the application of SWE improved growth and alleviated the impact of salinity stress.

Our results show that the contents of chlorophyll a, chlorophyll b, and carotenoids of M. oleifera leaves were significantly decreased under salinity stress compared with plants grown under normal conditions (Fig. 4). Salinity might be beneficial for Chl. B at moderate levels; the effect of salinity on carotenoids was inconsistent (no progressive decrease). The salinity-induced chlorophyll reduction could be primarily related to either the slowdown in chlorophyll biosynthesis or accelerated enzymatic chlorophyll degradation³⁶.

Fig. 4.

Effect of salinity on content of photosynthetic pigments (Chl. a, Chl. b, carotenoids, and total pigments) of Moringa oleifera seedlings amended with extracts of the seaweeds T. ornata and A. fragilis. Each column represents the mean ± SE (n = 3). Means followed by the same letters are non-significantly different at P < 0.05.

Treatment of Moringa with seaweed extracts significantly improved pigment content and alleviated the stress effect on pigments, with a stronger beneficial effect of T. ornata than A. fragilis (Table S2 and Fig. 4). This increase in chlorophyll content could be a result of a reduction in chlorophyll degradation, which might be caused in part by betaines in the seaweed extract³⁵. Moreover, the , soluble sugars, and mineral nutrients in T. ornata and A. fragilis extracts likely improved osmotic adjustment under salinity stress, thereby maintaining chloroplast integrity. Furthermore, these results reveal that the algal extract contained high levels of antioxidant , which were positively correlated with increased photosynthetic pigments under salt conditions. Protection of the photosynthetic apparatus and chlorophyll molecules within the thylakoid membranes from excessive reactive oxygen species (ROS) is accomplished via quenching of singlet oxygen and other free radicals..These mechanisms may contribute to the enhanced pigment content observed in our study. Our findings are in partial agreement with previous reports on the utilization of seaweed biofertilizers to improve crop resilience under abiotic stress³⁷

It is evident that the soluble carbohydrate content was significantly decreased with increasing levels of applied salt treatments (Fig. 5). The increase in sugar content by SWE is evident both under salinity stress and in the absence of salinity. The salinity-amendment interaction was highly significant on soluble carbohydrate content of leaf and root, indicating that the impact of algae depends on the salinity level (Table S3). This beneficial role of algal extracts in increasing moringa sugar content may be attributed to their high levels of minerals, soluble sugars, amino acids, antioxidants, and cytokinins . These substances can enhance plant performance and protect plants against ROS production, osmotic stress, and membrane injury under salt stress^38–40. Further investigation of the possible roles of individual antioxidant enzymes is warranted to ensure that seaweed-based biostimulants can bedeveloped more consistently and reliably by employing standardized extraction methods, comprehensive chemical tests, and uniform application procedures.

Fig. 5.

Effect of salinity stress, algal amendment (Amend), and their interaction on soluble carbohydrates content of Moringa oleifera. Each column represents the mean ± SE (n = 3). Means followed by the same letters are non-significantly different at P < 0.05.

The present findings indicate significant effects of salinity, algal amendment, and their interaction on the phenolic content of moringa leaves (Table S3). Whereas salinity increased the phenolic content of M. oleifera leaves, algal amendment led to the opposite effect. The reduction in total phenolic content following seaweed extract application may be attributed to the biostimulatory effects of seaweed-derived compounds³⁴. These extracts enhance plant growth and alleviate oxidative stress, thereby reducing the need for secondary metabolite production (Fig. 6).

Fig. 6.

Effect of salinity stress, algal amendment, and their interaction on the content of phenolic compounds in Moringa oleifera leaves. Each column represents the mean of triplicate measurements ± SE. Means followed by the same letters are non-significantly different (p < 0.05).

Biochemical and physiological responses of plants to seaweed extracts

Biochemical assays and GC–MS analysis collectively demonstrated the beneficial effects of seaweed extracts derived from Turbinaria ornata and Actinotrichia fragilis on Moringa oleifera plants under salinity stress.

These effects may contribute to enhanced pigment accumulation and plant growth. Seaweed extracts (SWEs) are frequently described as having a slightly alkaline nature (Table 1), which could influence soil acidity and, consequently, nutrient availability; however, soil pH was not measured in the present study, and thus these effects remain speculative. Notably, our compositional analysis revealed higher contents of magnesium (Mg) and potassium (K), but lower levels of calcium (Ca) and zinc (Zn), in Turbinaria ornata compared with Actinotrichia fragilis. The relatively elevated Mg and K levels in T. ornata may partially account for its more pronounced beneficial effects, given the established roles of Mg in chlorophyll structure and photosynthetic function, and K in osmotic regulation, enzyme activation, and stomatal control. In addition, the extracts contain varying concentrations of essential ions, including potassium, calcium, and magnesium, which play critical roles in osmotic regulation, enzyme activation, and photosynthetic processes. Taken together, these attributes suggest a potential role for SWEs in improving biomass production, plant nutritional status, and tolerance to abiotic stress, although further targeted investigations are required to substantiate these mechanisms under the specific conditions of this study⁴¹.

salinity stress significantly affects plant metabolism, as evidenced by changes in photosynthetic pigments, osmolytes, and total phenolic content. The application of seaweed extracts resulted in a marked increase in chlorophyll and carotenoid contents, indicating improved photosynthetic capacity and protection of the photosynthetic apparatus. By contrast, total phenolic content was significantly elevated under salinity stress, thus confirming the role of phenolics as a stress indicator. However, seaweed extract treatment attenuated this increase, suggesting reduced oxidative stress. This finding indicates that the accumulation of phenolic compounds is primarily a response to stress conditions rather than a direct mechanism of enhanced tolerance.

The GC-mass analysis, detailed in Fig. 2, is critical in categorizing SWEs based on their biochemical compounds and functional groups. This spectroscopic technique provides essential insights into the diverse functionalities of these extracts, which are pivotal for their optimized use in agriculture.

Understanding the concentration and the diversity of these specific compounds is vital for determining the targeted impacts of SWEs on plant growth and development, as illustrated the uniqueness of the superior seaweed T. ornata relative to A. fragilis in the composition and nature of its phytochemicals. By analyzing these components, GC-mass provides a comprehensive view of the biochemical makeup of SWEs , revealing their complexity and potential as versatile tools in agriculture.

By considering both the intrinsic properties of the extracts and the external factors that influence their composition, we can more effectively harness the full potential of SWEs. This approach enables the development of natural, sustainable biofertilizers tailored to specific agricultural needs, thereby enhancing crop productivity and environmental sustainability. Overall, the combined biochemical and GC–MS results indicate that seaweed extracts enhance plant resilience to salinity stress by improving photosynthetic efficiency, promoting osmotic balance, and supplying bioactive compounds that mitigate oxidative stress. These findings support the use of seaweed extracts as effective biostimulants for improving plant performance under adverse environmental conditions.

Heat Map Analysis provides a united view of how salinity and algal extract (T. ornata and A. fragilis) treatments influenced the physiological and biochemical traits of Moringa (Fig. 7). The grouping of treatments in the upper dendrogram revealed two main clusters. The first cluster consisted of moderate salinity levels (100–200 mM NaCl) combined with algal extract, which were associated with improved biomass (fresh and dry weights) and higher pigment and metabolite contents. This suggests that the algal extract application effectively mitigated the adverse effects of moderate salt stress by maintaining photosynthetic pigments and promoting carbohydrate accumulation. Similar positive effects of algal extracts under salinity stress have been reported, in which bioactive compounds, such as soluble sugar and phenolics, improved osmotic adjustment and antioxidative capacity, as illustrated by Abdel Latef et al.⁴⁰. By contrast, the second treatment cluster grouped the control and severe salinity conditions (300 mM NaCl), with or without SWE. These treatments were generally associated with reduced chlorophyll levels and lower biomass accumulation, highlighting the limited capacity of algal extracts to offset the detrimental effect of high salinity. Although algal extracts improved some traits even at 300 mM NaCl, the clustering clearly shows that the stress intensity outweighed the extract’s ameliorative effect at this level.

Fig. 7.

Heat map analysis combined with hierarchical cluster analysis of M. oleifera responses to the interaction of salinity and seaweed extract (SWE) of T. ornata and A. fragilis. The map shows the clustering of treatments and measured variables under different NaCl and SWE treatments. The upper dendrogram represents treatment clustering, while the left dendrogram groups the variables. Treatments are: (1) control (no salinity, no SWE), (2) 100 mM NaCl, (3) 200 mM NaCl, (4) 300 mM NaCl, (5) 0 mM NaCl + T. ornata extract, (6) 100 mM NaCl + T. ornata extract, (7) 200 mM NaCl + T. ornata extract, (8) 300 mM NaCl + T. ornata extract, (9) 0 mM NaCl + A. fragilis extract, (10) 100 mM NaCl + A. fragilis extract, (11) 200 mM NaCl + A. fragilis extract, and (12) 300 mM NaCl + A. fragilis extract5.

Conclusions

This study reveals that extracts of the seaweeds Turbinaria ornata and Actinotrichia fragilis applied to Moringa oleifera plants under salinity stress improved growth and performance and enhanced plant resilience to salt stress by increasing photosynthetic pigments and osmolytes . Nevertheless, the effect of seaweed extracts in alleviating salinity stress was consistent as a moderation of the salinity-induced increase in phenolic content of moringa leaves. Consequently, the elevation in phenolic content can be considered as a sign of stress rather than a resilience mechanism. Future research is needed to clarify the mechanisms of action of the bioactive compounds in these seaweeds, as well as to conduct comparative evaluations of seaweed extracts and conventional fertilizers to determine their relative effectiveness and agricultural Potential.

Author contributions

“Conceptualization and methodology, E.A.A.; software, E.A.A., N.L., and M.N.A..; validation, E.A.A. and N.L, formal analysis, E.A.A.; M.N.A and N.L.; resources, E.A.A.; data curation, E.A.A.; M.N.A., and N.L.; writing—original draft preparation, E.A.A. and N.L.; writing—review and editing, E.A.A. and N.L.; visualization, E.A.A. and N.L supervision, , E.A.A. project administration, E.A.A.; funding acquisition, M.N.A. All authors have read and agreed to the published version of the manuscript."

Funding

This study was funded by the Princess Nourah bint Abdulrahman University, Researchers Supporting Project Number PNURSP2026R103, Princess Nourah bint Abdulrahman University, Riyadh, Saudi Arabia.

Data availability

The data presented in this study are available on request from the corresponding author.

Declarations

Competing interests

The authors declare no competing interests.