The research was conducted in the solar greenhouse of Awati County, Aksu Prefecture, and Xinjiang Province during October to December 2024. There is a heating device in the greenhouse to confirm the standard growth of ice plant. During the experimental period, daily average temperature and light intensity variations were recorded using the RR-9100 recorder (Beijing Yugen Technology Co. Ltd., Beijing China) as show in Figure 1 . The experiment selected crystal ice plant as the research object, selected 4 to 5 leaves, and the plants with uniform and strong growth were transplanted into the hydroponic box for 5 days before treatment. The nutrient solution was replaced every 3 to 5 days during the hydroponic process.

The experiment was conducted with a completely randomized design (CRD) using three replicates. Set 6 concentrations of compound salt stress treatment. During the research, the nutrient solution was exchanged regularly every 3 to 5 days. On the basis of distilled water, irrigation water was made of fresh water and chemicals Na₂SO₄, NaCl, NaHCO₃, CaCl₂, MgCl₂ in a mass ratio of 8:8:1:1:1 (simulating the slightly salty water in southern Xinjiang); 100 plants were treated in each treatment, a total of 700 plants, and the ice plant was cultivated for 40 to 50 days. The various physiological indicators were measured when the ice plant was edible. A total of 6 treatments (T1~T6) were set up in the experiment, with the concentrations of the composite saline-alkali solution being 5g/L, 10g/L, 15g/L, 20g/L, 25g/L, and 30g/L, respectively, with pure distilled water as the control (CK). The specific configuration method of the composite saline-alkali solution is to mix Na₂SO₄, NaCl, NaHCO₃, CaCl₂, MgCl₂ in the proportion of 8:8:1:1:1 on the basis of distilled water.

Data analysis is carried out as mean and standard error (SE) were analysed by using two-way analysis of variance (ANOVA) followed by least significant difference (LSD) test at a significance (p ≤ 0.05) level with three replications. Analyses were performed using the STATISTICA application version 13.5.0.17.

Ice plants grown under different salt treatments showed appreciable differences in morphological parameters such as stem thickness, plant height, number of leaves, leaf area, thick leaves and SPAD to T2 treatment in the presence of saline-alkali solution of 10 g/L are showed in Table 1 . Halophytes ice plant response to moderate salt concentration promotes their growth, whereas excessive salt concentration impairs their growth (Alkharabsheh et al., 2021; Hasanuzzaman et al., 2023; Eoh et al., 2024). The decrease in root growth under high salt conditions may be due to a shift of energy from growth to maintaining osmotic pressure and facilitating toxin removal processes (Ahmad et al., 2024). Moreover, such contrasts between environmental and salinity stresses reflect plant adaptations, likely to shift energy from shoot growth to help aboveground organisms maintain osmotic balance and improve survival under salinity stresses (Tyśkiewicz et al., 2022). The stem thickness, plant height, number of leaves, leaf area, thick leaves and SPAD were significantly lower under the T6 treatment in the presence of saline-alkali solution of 30 g/L than that the CK treatment and displayed a decreasing trend with increasing stress severity. Drought and salt stress are believed to be important drivers of plant developmental processes that can lead to a decrease in chlorophyll (Fang et al., 2024; Ren et al., 2005). However, treatment of plants with 10 g/l saline led to an increase in these parameters in all combined control treatments. The 10 g/l saline water and the percentage increase in root fresh weight, plant height, leaf number, leaf area, and leaf thicknes were 15.8%, 39.2%, 24.0%, 34.0%, and 31.5%, respectively, than those of 30 g/l saline solution. Kim et al. (2012) also found that ice plant leaf number, lateral leaf number, and leaf area were positively correlated with leaf and leaf biomass. Ahlawat et al. (2024) confirmed that 400 mM NaCl improved the fresh weight of rice seedlings by 2 times compared to the control seedlings. Therefore, high salt concentrations may affect the biomass increase of snow plants.

Ice plant grown under various salt concentrations indicated a significant variance in properties such as SPAD value, shoot and dry weight (g/plant), root volume, and root activity. The increasing trend of chlorophyll contents observed in 200 mM NaCl solution may indicate that plants are in a stress adaptation stage where they optimize their photosynthetic apparatus to cope with oxidative stress (Bekmirzaev et al., 2020; Wrzecí et al., 2022). Then, as shown in Table 1 , SPAD values ​​of T2 and T3 treatments were significantly higher, while SPAD values ​​of T5 and T6 treatments were lower. Moreover, this opposite behaviour between moisture and salt stresses reflects a plant adaptation, which may be shifting energy from root growth to helping roots osmotic pressure and improve survival at moderate salt stress (Quezada-Martinez et al., 2021). Root weights were measured to investigate their growth under diverse saline and alkaline conditions. When grown in 10 g/L saline-alkaline solution, shoot and root FW of plant 1 were 299 and 17 g/plant, respectively ( Figure 2 ). Similarly, root volume and root activity of T2 treatment were considerably greater than all other treatments, respectively. Bohnert and Cushman (2000) reported that accumulate salt storing large amounts of NaCl and CaCl₂ in the shoot. Furthermore, this salt-loving plant grows well in a salt environment with salinity ranging from 100 to 400 mM (Asad et al., 2024).

Exogenous application of saline-alkaline solution significantly affected the soluble protein, total sugar, vitamin C and flavonoid of ice plant under the salt stress condition ( Figure 3 ). Compared with CK, different degrees of saline-alkaline solution salt stress significantly improved the soluble protein, total sugar, vitamin C and flavonoid of T2 treatment, which were 12.9, 40.1 and 290.1 ​​mg g^-1, respectively. The vitamin C content was 26.2 mg/100g, which was higher than all other treatments. Therefore, MT application could increase the proline of plants under saline soil, which could help increase the osmotic potential of leaves, enhance water absorption, promote photosynthesis, and ultimately improve the characteristics of plants under saline soil (Zaher-Ara et al., 2016). The effect of saline-alkaline solution application depends on the type of application and the concentration of the saline-alkaline solution. The contents of soluble total sugar, protein, vitamin C, and flavonoid compounds in both T1 and T2 treatments first increased with the increase of saline-alkaline solution concentration, and all reached a peak value of 10 g L^-1 in T2 treatment, and then decreased with further increase of saline-alkaline solution concentration. Flavonoids content can protected from biotic and abiotic stresses through antioxidant activities (Taha et al., 2021; Ibrahimova et al., 2021). In T6 treatment, the soluble total sugar and flavonoid contents monotonically reduced with the intensification of saline-alkaline solution concentration and reached the lowest value. The soluble total protein content of 10 g L^-1 saline-alkaline solution under salt stress increased significantly compared with CK treatment, and the application of saline-alkaline solution had a significant effect on the soluble total protein content in T2 and T3 treatments. Under CK treatment, the soluble protein and sugar content decreased considerably, and the largest increase occurred at 10 g L^-1. Under T4 and T5 treatments, the application of saline-alkaline solution significantly decreased vitamin C, and the smallest decrease occurred at 20 and 25 g L^-1, respectively. Under salt stress conditions, plants accumulate water-retaining compounds, soluble sugars (Muhammad et al., 2024), and proline (Li et al., 2024) to maintain water balance and prevent plant dehydration under drought conditions. Proline helps scavenge ROS, stabilize cell membranes, and inhibit protein and enzyme degradation under salt stress (Ors et al., 2021). Table 2 shows the Pearson correlation coefficients between antioxidant enzyme activities, reactive oxygen species, antioxidants, growth factors, protein, proline, and MDA contents of snow leaf leaves. A significant positive correlation was observed between flavonoid content and H₂O₂ content, K⁺, LA, plant height, SPAD, dry weight, and dry weight, whereas a negative correlation was observed with protein content.

The SOD, POD, CAT, and AsA activities were considerably different among the different water treatments ( Figure 4 ). These factors are essential for reducing ROS-induced damage by increasing the plant’s disease resistance, especially in the root system, which is consistent with the decrease observed in vascular plants (Muneeba et al., 2024; Fang et al., 2024). The SOD and CAT were significantly higher in T3 treatment compared to all other treatments. Whereas, the activities of POD and AsA were significantly higher in T2 treatment than in other treatments. However, there were also significant differences in the formation of toxins among the different aqueous solutions, and the patterns of antioxidant enzymes also differed. The 500 mM NaCl showed the ability to form a protective layer and increase the weight of the cells. Plant flavonoids have free radical scavenging and free radical scavenging effects, which may involve the following mechanisms: (a) inhibition of ROS production by inhibition or activation of free radical scavengers; (b) ROS scavenging; and (c) increased immunity (Ahmad et al., 2024; Hussain et al., 2024). The T2 treatment (10 g L^-1) produced the highest MDA content compared with all other treatments ( Figure 4 ). Application of 30 g L^-1 saline solution under saline conditions had a significant effect on ROS production in ice plant. Furthermore, significant positive correlations were observed between stem dry weight and CAT, FC, K⁺, LA, plant height, SPAD, and surface roughness. Correlation analysis also showed positive correlations between MDA and POD, soluble protein, AsA, CAT, and Cl⁺ levels.

The highest SOD content and production were observed under the condition of 15 g L^-1 saline solution. This is because these ROS play a critical role in key signaling pathways associated with the stress response (Alam et al., 2021; Urmi et al., 2023; Fang et al., 2024). Inhibition of these types of ROS and their subsequent damage by SOD and CAT is a key mechanism of action (Madhavi et al., 2021; Aslam et al., 2023). As expected, the CK treatment had the lowest levels of CAT, POD, and AsA. However, there was non-significant variance in proline content between the CK and T1 treatments, with T1 treatment producing significantly lower levels of proline. The production of ROS (H₂O₂ and O₂ ^-) was the highest when 30 g L-1 of saline solution was applied, while the production of ROS (H₂O₂ and O₂ ^-) was the lowest in the T1 treatment with 5 g L^-1 of saline solution ( Figure 5 ). Plants use a variety of antioxidants to regulate ROS production and thus prevent salt stress-induced damage by effectively scavenging ROS or restoring intracellular antioxidant levels (Seleiman et al., 2022; Hussain et al., 2024). There was no difference in H₂O₂ production between T3 and T4 treatments. However, the highest POD, AsA, and MDA activity values ​​were detected in the T2 treatment. While on other hand, the highest levels of SOD and proline were present in T4 treatment. It is known that abiotic factors such as salinity and drought stresses increase the ROS activity, which induces oxidative stress and plant oxidative pathways (Tyśkiewicz et al., 2022; Nazir et al., 2023). The strong interaction network emphasized the important role of polyphenols in the antioxidant activity of M. crystallinum under salt stress, indicating that the pathogen system was more efficient under optimal salt stress conditions (Bekmirzaev et al., 2020; Aslam et al., 2023; Ahmad et al., 2024).

The results showed that snow plant accumulated more K⁺ under CK treatment, while the contents of Na⁺, Cl⁺, and Na⁺/K⁺ were higher under T6 treatment ( Figure 6 ). Na⁺ is the major ion responsible for salt degradation in plants. Since the ionic radius and adsorption capacity of Na⁺ are comparable to those of K⁺, higher concentrations of Na⁺ and decrease K⁺ absorption by inhibiting movement, resulting in Na⁺ toxicity and K⁺ leaching (Shah et al., 2021; Huang et al., 2021). There was no significant difference in Na⁺ retention in the leaves of snow-covered plants under T4, T5, and T6 treatments. In addition, the Na⁺ content in T4, T5, and T6 treatments was highest because salt transport from root cells to the mesophyll depends on inositol, and inositol interactions facilitate the uptake and long-distance transport of salt. It has been reported that many halophytes accumulate Na⁺ in their leaves and roots in biosaline cultivation, which leads to a decrease in cation such as K⁺ (Ors et al., 2021; Bagwasi et al., 2020). According to the results of K⁺ ion determination, CK application had the highest value, and T6 application had the lowest value. There was non-significant variance in K⁺ ion accumulation between T5 and T6 applications. These results indicate that lower CaCl₂ concentrations affect K⁺ ion accumulation in leaf tissues. However, Na⁺, and K⁺, sorption rates were higher in CaCl₂ salt application because NaCl inhibits K⁺ ion concentration, while CaCl₂ increases Cl and Ca²⁺ content in leaves, leading to the sorption of other cations (Aslam et al., 2023; Hasanuzzaman et al., 2023). As Cl⁺ levels increased, significant differences were observed in the T4 (41 ± 20 g/L) and T5 (43 ± 25 g/L) treatments.

The excretion, transport, and sequestration of toxic ions are highly relevant to water conservation, which will be discussed later, as efficient water conservation requires a balance between Na⁺ and Cl⁺ in the vacuole and between K⁺ and solute receptors. The Na⁺ concentration and Na⁺/K⁺ ratio of the T1 was considerably lower as compare with other treatments, and the other treatments were relatively equal. The Na⁺/K⁺ ratio in the T6 were considerably higher as compared with CK treatment. The Na⁺/K⁺ ratio was the lowest in CK and T1 treatments. On the other hand, the T6 treatment (15 g of/L) had the maximum Na⁺, Cl⁺, and Na⁺/K⁺ ratios. K⁺ and Na⁺ have similar chemical properties, so their absorption and distribution are based on a common transport system, and excess Na⁺ can compete with K⁺. This affects the Na⁺/K⁺ ratio and leads to K⁺ deficiency, which in turn affects growth and stress resistance (Ren et al., 2005; Abbas et al., 2017; Huang et al., 2021). There are many Limitations of hydroponics studies over conventional agriculture, there are some, higher set up cost, growers require skill and knowledge to maintain optimum production in commercial applications (Nazir et al., 2023), because each plant in a hydroponics system is sharing the exact same nutrient, diseases and pests can easily affect each plant, plants react quicker to changes in the environment (Muneeba et al., 2024), however, if this change is for the worst, plants will quickly react to it; showing signs of deficiency or trouble, hot weather and limited oxygenation may limit production and can result in loss of crops (Hasanuzzaman et al., 2023).