Increasing Sugarcane Salinity Resistance with Silicon Fertilizer by Preventing the Absorption of Na+ and Cl- and Improve Antioxidant Defense System

doi:10.21203/rs.3.rs-4279520/v1

Download PDF

Research Article

Increasing Sugarcane Salinity Resistance with Silicon Fertilizer by Preventing the Absorption of Na+ and Cl- and Improve Antioxidant Defense System

https://doi.org/10.21203/rs.3.rs-4279520/v1

This work is licensed under a CC BY 4.0 License

Version 1

posted

You are reading this latest preprint version

Aims

Irrigation with saline water is becoming increasingly common in arid and semi-arid environments, where irrigation is necessary for crop production. However, the high demand for sugarcane and limited access to water in these areas pose significant challenges. This study aims to determine the effect of powdered silicon fertilizer on the ability of sugarcane to withstand salinity stress.

Methods

This study uses a split-split plot design within a completely randomized design (CRD). The main plot factors included three levels of salinity: control of 1.4±0.2 dS.m^-1 (S0) from the river water source, salinity stress of 4.1±0.2 dS.m^-1 (S1), and salinity stress of 8.2±0.2 dS.m^-1 (S2) from the drain water source, with a sub-factor of variety treatment (CP73-21 (V1) and CP69-1062 (V2)).

Results

The results indicated that salinity stress led to a reduction in stem height, SPAD index, relative water content, stomatal conductance, and photosynthesis rate compared to the control by 65.5%, 27%, 10.8%, 38.5%, and 41.8%, respectively. In addition, the concentrations of Na⁺ and Cl^- in the leaves, electrolyte leakage, malondialdehyde, and proline, increased by 75%, 50%, 22.7%, 81.5%, and 67%, respectively.

Conclusions

However, nutrition silicon one month before salinity stress improved physiological, biochemical, and cell membrane stability characteristics and maintained leaf photosynthesis. Overall, the results illustrate that feeding sugarcane with silicon (Si) fertilizer can improve its tolerance to salinity stress by enhancing physiological processes, antioxidant enzymes, and ionic homeostasis.

Anti-oxidants

Salinity Stress

Silicon

Sugarcane

The high-water requirement of sugarcane in arid and semi-arid regions, coupled with a decrease in rainfall, has led to an increase in the use of drainage water for sustainable production management. According to Zhao et al. (2021), it has been estimated that 20% of all cultivated land and 33% of irrigated agricultural land are affected by high salinity. Salinity stress poses two main threats to plants: ionic toxicity and osmotic stress. Ionic toxicity occurs when there is a significant buildup of Na⁺ in the leaves in a saline environment. This disrupts the balance of water and ions in plants, damages organelle structure, and inhibits plant growth, potentially leading to death (Munns & Tester, 2008). Some studies have shown that ion toxicity caused by Na⁺ can inflict more irreversible damage on plants than osmotic stress (Ali et al., 2021; Wu, 2018).

Osmotic stress can lead to increased levels of reactive oxygen species (ROS) in plants that are exposed to salinity stress. These ROS can cause damage to macromolecules and lead to lipid peroxidation, ultimately inhibiting plant growth (Ahmad et al., 2019). To counteract the harmful effects of ROS and maintain a balanced intracellular environment, plants have developed enzymatic and non-enzymatic antioxidant systems (Chiappero et al., 2021). Enzymatic antioxidants, such as superoxide dismutase (SOD) and catalase (CAT), reactive oxygen species (ROS), while non-enzymatic antioxidants, such as proline, soluble sugars, and soluble proteins, accumulate to regulate this imbalance (Conceição et al., 2019).

The salt tolerance of plants can be increased by using specific nutrients, such as silicon, zinc, boron, and potassium, as well as organic acids like salicylic acid, humic acid, and aspartic acid. Silicon (Si) is the second most abundant element on Earth and is known to accumulate in plant cells (Rao & Susmitha, 2017). Plants that are fed with silicon have been shown to have better resilience against both biotic and abiotic stresses. The exogenous application of silicon has been found to have a positive impact on the optimal K⁺/Na⁺ ratio, ion homeostasis, antioxidant production, and nutrient balance (Al Murad et al., 2020; Farouk & Omar, 2020).

Similarly, a study on maize found that plants treated with silicon (Si) showed improved photosynthetic efficiency, growth, and yield compared to plants under salt stress (Khan et al., 2017). Previous studies have also shown that silicon treatments can increase salinity tolerance in various plants, including wheat (Ahmad et al., 1992), corn (Rohanipoor et al., 2013), rice (Flam-Shepherd et al., 2018), and canola (Hashemi et al., 2010). However, the extent of silicon-mediated benefits under salinity can vary greatly between species and is largely dependent on the plant's capacity for element uptake dictated by its genetic makeup (Dhiman et al., 2021).

There is limited information regarding the use of drainage water in sugarcane irrigation management in arid and semi-arid regions, as well as the potential for improving salinity stress through silicon application. Therefore, this study was conducted to evaluate the effect of Si on sugarcane organs irrigated with salt water.

2.1. Experimental Design and Treatments

The pot experiment was conducted in a greenhouse with natural light at the agricultural site of Sugarcane Dehkhoda Company in Khuzestan Province, Iran, in 2021–2022. The temperature and humidity percentages are indicated in Fig. 1. This study uses a split-split plot design within a completely randomized design (CRD). The main plot factors included three levels of salinity: control of 1.4 ± 0.2 dS.m^− 1 (S0) from the river water source, salinity stress of 4.1 ± 0.2 dS.m^− 1 (S1), and salinity stress of 8.2 ± 0.2 dS.m^− 1 (S2) from the drain water source, with a sub-factor of variety treatment (CP73-21 (V1) and CP69-1062 (V2)). The pots are made of polyethylene, which has a drainage hole at the bottom for water drainage. The salt stress was applied 113 days after germination and continued until harvest. Additionally, the chemical analysis of the drainage water used in the experiment is listed in Table 1. The silicone application timing was also considered as a sub-factor, with four levels: Si0, non-silicone application (Control); Si1, one month before salinity stress; Si2, during salinity stress; and Si3, (After 30 days of salt stress, silicon was applied).

Table 1

Results of chemical analysis of drainage water in year 2022
EC (ms/cm)	TDS (mg/l)	Na⁺ (Meq/l)	Ca²⁺ + Mg²⁺ (Meq/l)	SAR	(NO₂⁻+NO₃⁻ ) (mg/l)	CO₃²⁻ (Meq/l)	HCO₃ˉ (Meq/l)	Clˉ (Meq/l)	SO₄²⁻ (Meq/l)	K^+ 2 (Meq/l)
8.49	5094	66.52	24.50	13.44	5.83	0.60	4.32	53.58	47.27	1

2.2. Silicon fertilization

Silicon was applied when the seedlings were either 80 days old (May 20, 2022), 110 days old (June 20, 2022), or 140 days old (July 20, 2022). The source of additional silicon was powdery mineral silicon (Sitam, Ariashimi Co, Iran; 70% SiO2). Silicone fertilizer was applied to the base of the plant in the form of a solution, with a dosage of 114 mg per pot.

2.3. Gas exchange attributes

Stomatal conductance (gs), photosynthetic rate (A), and transpiration rate (E) were measured on fully expanded uppermost leaves using a portable IRGA (Infra-Red Gas Analyzer, Hoddesdon, UK) at the light saturation intensity between 9:00 am and 12:00 noon on a sunny day, following the method described by Emanuil et al. (2020).

2.4. Water related attributes (RWC) and Electrolyte leakage (EL)

Small pieces of leaves were dipped in deionized water, and the level of electrolyte leakage (EL) was measured. The initial measurement of EL was conducted after incubating the sample at 32˚C for 2 hours, and the subsequent measurement was taken after incubating the sample at 121˚C for 20 minutes (Dionisio-Sese and Tobita, 1998). The EL level of samples was calculated using the following formula:

EL = (EC₁/EC₂) × 100

Electrolyte leakage (EL) was measured by Dionisio-Sese and Tobita (1998). The EL level of samples was calculated using the following formula:

RWC = [(FW – DW)/(TW – DW)] × 100

FW = Fresh Weight; TW = Turgid Weight; DW = Dry Weight

2.5. Mineral Attributes

The concentration of Na⁺ in leaves was determined using a wet digestion technique. To prepare the sample solution, 0.5g of leaf material was digested in 10 ml of di-acids (HNO3-HClO4) (Estefan et al., 2013). To prevent chlorine loss, 6 mL of 2% K2CO3 was added to 1 gram of dried plant material before ashed at 550°C for 60 minutes in a muffle furnace (Johnson et al., 1958).

2.6. Enzymatic antioxidants, Malondialdehyde (MDA) and Proline content

Catalase activity (CAT) was determined following the method presented by Aebi (1984). The superoxide dismutase activity (SOD) was assayed following the procedure presented by Bayer (1987). Ascorbate peroxidase (APX) activity was determined by monitoring the oxidation rate of ascorbate at a wavelength of 290 nm at 30°C for 60 seconds in a spectrophotometer (Nakano & Asada, 1981). The MDA content was measured according to a previously described method (Zhang et al., 2020). Following the method of Maehly and Chance (1954), the proline content was determined. Sulphosalicylic acid (3% w/v) was mixed with a 0.5 g sample of fresh leaf and then filtered.

2.7. Statistical analysis

The data were generally subjected to statistical analysis by GLM using SAS 9.4 for Windows (SAS, USA). Pearson correlation coefficients were estimated to determine the association between combined data across the gradient salinity stress morphological and physiological traits.

The presence of saltwater stress significantly impacted the quantitative and qualitative traits (Table 2). The height of the sugarcane stem decreased significantly due to increasing electrical conductivity of the water. The stem height of the control treatment, which used river water, was 34.6% and 65.5% higher than that of S1 and S2, respectively (Table 3). However, the height of the sugarcane stem decreased significantly due to the salinity of the water. The CP69-1062 variety has better performance in all traits except for electrolyte leakage (Table 3). The superiority of CP69-1062 over that CP73-21 under saline stress may be attributed to its genetic origin. According to the results, the optimal time to apply Si fertilizer is one month before subjecting the plants to salt stress. This timing resulted in significant increases in stem height (15.2%), SPAD (3.3%), RWC (2.5%), stomatal conductivity (2%), and rate of photosynthesis (3%) as compared to the control treatment (Table 3). Furthermore, the application of Si fertilizer one month before salt stress (Si1) reduced leaf electrolyte leakage by 4.5%. Therefore, it can be acknowledged that the application of silicone fertilizer can effectively alleviate salt stress in sugarcane. However, the timing of application is crucial for maximizing the benefits of silicon. The most notable impact was observed under stress conditions, indicating that Si feeding helps to maintain plant moisture levels. Upon comparing averages, it was found that sugarcane leaves in the S1 and S2 treatments contained 180% and 300% more Na⁺ ions, respectively, than the control treatment. Additionally, the levels of Cl⁻ ions were 63% and 100% higher in the S1 and S2 treatments, respectively. The CP73-21 variety exhibited a higher accumulation of Na⁺ and Cl⁻ ions, with levels of 37.5% and 7.1% respectively, in comparison to the CP69-1062 variety (Table 5). The absence of salt stress in the control treatment resulted in the lowest levels of Na⁺ and Cl⁻. Interestingly, both varieties responded in the same way to varying levels of electrical conductivity. Exposure of sugarcane to salinity stress resulted in increased accumulation of Na⁺ and Cl⁻ in the leaves. However, the application of silicon significantly reduced this accumulation at various salinity levels.

Table 2

Results of variance analysis of sugarcane ecophysiological traits under salinity stress with silicon application
SOV		df	Stem height	Rate of photosynthesis	RWC	SPAD	Stomatal conductance
Blok	2	3.56	13.40	4.81	0.23	0.69	1.46
Salinity stress (S)	2	114637^**	3249^**	506.2^**	943.83^**	5865^**	2689^**
Error S	4	7.51	12.08	0.55	2.84	28.54	0.18
Variety (V)	1	100.82^**	256.8^**	18.80^**	18.50^**	482.51^**	97.53^**
S×V	2	7.13^n.s.	32.52^**	2.73^n.s.	0.22^n.s.	61.39^**	1.34 ^n.s.
Error V	6	9.91	4.03	0.45	0.46	9.91	0.69
Silicon (Si)	3	1636.6^**	5.70^*	18.15^**	5.53^*	5.75^**	12.65^**
S×Si	6	274.72^**	0.29^n.s.	2.76^*	0.59^n.s.	2.13 ^n.s.	0.88 ^n.s.
V×Si	3	10.54^n.s.	0.69 ^n.s.	0.02^n.s.	0.08^n.s.	0.80 ^n.s.	0.50 ^n.s.
S×V×Si	6	12.73^n.s.	1.69^n.s.	0.51 ^n.s.	0.21^n.s.	2.06 ^n.s.	0.66 ^n.s.
Total Error	36	9.19	1.52	0.95	1.33	1.12	0.75
CV%		2.15	2.95	1.22	3.18	1.60	2.38
^{, *,} significant at the 0.05 and 0.01 probability levels, respectively. ^n.s. not significant at P = 0.05.

Table 3

Effect of salinity stress and application of silicon fertilizer on selected traits of two sugarcane varieties
Treatment	Stem height (cm)	SPAD	RWC (%)	Stomatal conductance (mmol H₂O.m^− 2.s^− 1)	Rate of photosynthesis (µmol CO2.m^− 2.s^− 1)	Electrolyte leakage (%)
Salinity stress (S)
S0	210.7^a	43.4 ^a	84.8 ^a	80.54 ^a	54.5 ^a	34.3 ^c
S1	137.8 ^b	33.7 ^b	79.4 ^b	68.5 ^b	39.1 ^b	40.2 ^b
S2	72.6 ^c	31.7 ^c	75.6 ^c	49.5^c	31.7 ^c	44.4 ^a
Variety (V)
V1	139.2^b	35.8^b	79.4 ^b	63.6 ^b	39.9 ^a	37.47 ^a
V2	141.6^a	36.8^a	80.4 ^a	68.7 ^a	43.6 ^b	35.14 ^b
Silicon (Si)
Si0	131.8^c	35.6^b	79.3 ^c	65.5 ^c	41.05^b	37.2 ^a
Si1	151.9^a	36.8 ^a	81.3 ^a	66.8 ^a	42.3^a	35.5 ^b
Si2	144.5^b	36.6 ^a	80.1 ^b	66.3 ^ab	42.0^a	35.6 ^b
Si3	133.4^c	36.1^ab	79.1 ^c	66.0 ^bc	41.7^ab	36.7 ^a
Notes. S0, Stress level 1.5 dS.m^− 1 (Control); S1, Stress level 4.1 dS.m^− 1; S2, Stress level 8.2 dS.m^− 1; V1, CP73-21 Variety; V2, CP69-1062 Variety; Si0, no Silicon Application (Control); Si1, one month before salinity stress; Si2, Sometime of salinity stress, and Si3, one month after salinity stress. The means with the same letter(s) in column have no differences at the 0.05 probability level.

Table 4

Results of variance analysis for biochemical traits and mineral elements of sugarcane leaves under salt stress with silicon application
SOV	df	Leaf Na⁺	Leaf Cl⁻	Soluble proteins	MDA	CAT	APX	SOD	Proline
Blok	2	0.0001	0.064	0.321	0.395	16.10	2.02	0.787	0.098
Salinity stress (S)	2	0.144^**	0.760^**	0.094^**	35.32^**	2062.66^**	1184.09^**	159.88^**	91.27^**
Error S	4	0.0004	0.036	0.003	0.146	19.53	7.82	0.07	0.206
Variety (V)	1	0.049^**	0.035^**	0.486^**	0.032^n.s.	55.88^*	0.004^n.s.	5.359^**	8.74^**
S×V	2	0.304^**	0.113^**	0.037^**	0.043^n.s.	13.38^n.s.	3.80^*	0.197^n.s.	0.392^n.s.
Error V	6	0.0001	0.003	0.002	0.012	19.38	0.63	0.520	0.142
Silicon (Si)	3	0.0038^**	0.020^**	0.052^**	0.437^**	802.40^**	17.38^**	158.23^**	21.08^**
S×Si	6	0.0006^*	0.012**	0.034^**	0.165^**	225.71^**	1.62^n.s.	17.311^**	3.57^**
V×Si	3	0.0002^n.s.	0.004^n.s.	0.045^**	0.020^**	9.18^n.s.	0.55^n.s.	0.439^n.s.	0.461^n.s.
S×V×Si	6	0.0001^n.s.	0.003^n.s.	0.078^**	0.018^**	20.90^*	0.69^n.s.	0.225^n.s.	0.647^**
Total Error	36	0.0001	0.002	0.002	0.026	7.65	1.01	0.233	0.188
CV%		7.68	9.65	3.28	10.16	8.69	4.32	2.78	10.91
^{, *,} significant at the 0.05 and 0.01 probability levels, respectively. ^n.s. not significant at P = 0.05.

Table 5. Effect of salinity stress and application of silicon fertilizer on biochemical traits and mineral elements of two sugarcane varieties
Treatment	Leaf Na⁺ (%)	Leaf Cl⁻ (%)	Soluble proteins (mg g^− 1 FW)	MDA (nmol g^− 1 FW)	CAT (nmol min^− 1 g^− 1 protein)	APX (nmol min^− 1 g^− 1 protein)	SOD (U mg^− 1 protein)	Prolien (µmol g^− 1 FW)
Salinity stress (S)
S0	0.05^c	0.35^b	1.46^b	0.54^c	21.16^c	15.50^c	20.25^a	1.73^b
S1	0.14^b	0.57^a	1.48^b	1.13^b	36.44^b	25.33^b	16.26^b	4.96^a
S2	0.20^a	0.70^a	1.58^a	2.93^a	37.89^b	29.10^a	15.42^c	5.23^a
Variety (V)
V1	0.16^a	0.56^a	1.59^a	1.62^a	30.95^b	23.32^a	17.04^b	3.62^b
V2	0.10^b	0.52^b	1.42^b	1.58^a	32.71^a	23.30^a	17.59^a	4.32^a
Silicon (Si)
Si0	0.15^a	0.58^a	1.49^b	1.68^a	26.48^c	22.78^b	15.32^c	3.10^c
Si1	0.11^c	0.50^c	1.58^a	1.37^b	41.59^a	24.75^a	21.72^a	5.55^a
Si2	0.13^b	0.53^bc	1.50^b	1.66^a	29.52^b	23.10^b	16.23^b	3.67^b
Si3	0.13^b	0.54^b	1.45^c	1.69^a	29.72^b	22.60^b	15.98^b	3.57^b
Notes. S0, Stress level 1.5 dS.m^− 1 (Control); S1, Stress level 4.1 dS.m^− 1; S2, Stress level 8.2 dS.m^− 1; V1, CP73-21 Variety; V2, CP69-1062 Variety; Si0, no Silicon Application (Control); Si1, one month before salinity stress; Si2, Sometime of salinity stress, and Si3, one month after salinity stress. The means with the same letter(s) in column have no differences at the 0.05 probability level.

Figure 7 illustrates the accumulation of Na⁺ and Cl⁻ ions in the shoots of two sugarcane varieties (a and b). The absence of salt stress resulted in the lowest levels of Na⁺ and Cl⁻ in the treatment. It's interesting that both types of varieties responded in the same way to varying levels of saltiness. The CP69-1062 variety had fewer Na⁺ and Cl⁻ ions than the CP73-21 variety. Furthermore, as the salinity stress intensified, there was a significant increase in the accumulation of Na⁺ and Cl⁻ ions in the shoot.

Exposure of sugarcane to salinity stress resulted in increased accumulation of Na⁺ and Cl⁻ in the leaves. However, the application of silicon significantly reduced this accumulation at various salinity levels (see Fig. 9a and b). Specifically, the accumulation of Na⁺ was 166% and 300% higher in the S2 and S3 treatments, respectively, compared to the control treatment. In contrast, the use of silicon in the Si1 treatment led to a 20% and 33% decrease in Na⁺ accumulation compared to the saline treatment. Additionally, the concentration of Cl⁻ ions in sugarcane leaves was found to be 57% and 124% higher in S1 and S2 levels, respectively (Fig. 9b). When sugarcane was fed with silicon (Si1), the Cl⁻ concentration decreased by 5% and 27% in salinity treatments (S1 and S2, respectively). Furthermore, the application of silicon during stress (Si2) and one month after salinity stress (Si3) resulted in a reduction of both Na⁺ and Cl⁻ ions.

Furthermore, elevating the salinity level resulted in an increase in the soluble proteins in sugarcane leaves. The salinity levels of 4.1 dS.m^− 1 (S1) and 8.2 dS.m^− 1 (S2) resulted in a 2.6% and 3.9% increase, respectively, in leaf soluble proteins compared to the control treatment in variety CP73- 21. The values were 3.7% and 13% in variety CP69-1062, respectively (Fig. 8a). In treatment Si1, the leaves of variety CP73-21 were 17% higher than in variety CP69-1062, making it the largest increase among all treatments.

The lowest amount of MDA was observed in the control treatment, and it remained unchanged with the addition of Si (Fig. 9d). Salt stress significantly increased MDA levels in sugarcane leaves by 109–442% (Table 5). Figure 7d illustrates that sugarcane treated with Si resulted in a significant decrease in leaf MDA levels, although the reduction was relatively small (17.6% and 22.2% in the Si1 treatment, respectively).

The pattern of APX enzyme activity was similar and increased in the two cultivars tested (Fig. 8b). The lowest level of APX enzyme activity was observed in the control treatment and increased with rising salinity stress at levels S1 and S2 in the CP73-21 variety (57% and 81%) and CP69-1062 variety (67% and 91%), respectively, compared to the control.

The application of Si without salt stress (Si1) significantly increased SOD levels by 34.3% compared to the treatment without Si application. The highest activity of the SOD enzyme was observed in the Si1 treatment at all salinity levels (Fig. 9c). The pattern of increasing SOD enzyme levels was observed across all treatments.

In the accumulation of CAT and proline in the leaf, we observed significant interaction between salinity levels and Si application treatments (p < .001; Table 5). In salinity stress conditions, higher accumulation of CAT and proline was observed in the Si1 treatment (Fig. 9e and f). CAT content in the leaf increased by 145.5 and 114% in the S1 and S2, respectively, than the control treatment. On the other hand, Si1 resulted in an increase of 271 and 261.5% for proline in S1 and S2, respectively, when compared to Si0 (Fig. 9f).

Salinity stress is a major environmental challenge for plants, causing ionic toxicity and osmotic stress that hinder growth, reduce yield, and ultimately lead to plant death (Rizwan et al., 2015). Numerous studies have demonstrated the effectiveness of Si in mitigating the harmful effects of salinity stress on plants and promoting growth in saline environments (Al-Huqail et al., 2019; Hurtado et al., 2020). The results of our study showed that the impact of salinity stress on sugarcane ecophysiology traits was evident. As a glycophyte plant, sugarcane has a limited ability to absorb and store salt in its shoots. The presence of high levels of salt in the environment causes osmotic stress, reducing the plant's ability to absorb water through its roots. This decrease in water absorption results in a decrease in relative water content (RWC), causing the plant to lose its turgor pressure and experience physiological dryness. Additionally, the decrease in stomatal conductance and subsequent stomatal closure leads to a decrease in active photosynthesis and stem height. According to our findings, (Zhao et al., 2020) also reported a decrease in active photosynthesis in sugarcane due to salinity stress, attributed to a decrease in stomatal conductance and photosynthetic factors in the leaves. Additionally, Vasantha et al. (2010) found that photosynthetic rate, transpiration rate (t), and leaf water decreased due to salinity treatment in sugarcane.

The amount of Na⁺ in sugarcane leaves increased by 180% and 300% in salinity treatments S1 and S2, respectively. Consistent with these results, some researchers have reported high Na⁺ levels in plant cells and tissues due to increased salinity stress (Naveed et al., 2020). The increase in Na⁺ levels in different plant parts (e.g. leaves) is related to soil and root Na⁺ ions (Ju et al., 2021; Wang et al., 2013). In sugarcane, the application of Si fertilizer (Si1) resulted in a decrease of 26.7% and 13.8% in the accumulation of Na⁺ and Cl⁻ elements, respectively, compared to the control (Table 5). Some studies have demonstrated that Si can act as a mechanical barrier to prevent the uptake of Na⁺ by roots (Garg & Bhandari, 2016; Khan et al., 2017). Additionally, according to El-Habet (2021), the application of Si led to a significant increase in the weight and length of shoots and roots, as well as the grain yield of rice irrigated with drainage water, compared to the control treatment. Furthermore, the application of Si has been shown to significantly inhibit Na⁺ uptake and transfer from roots to shoots in sugarcane under salt stress (Ashraf et al., 2010). The RWC and electrolyte leakage are measures used to deal with salinity stress (Abdelaal et al., 2019). Shah et al. (2021) showed a significant decrease in RWC under higher salinity levels. These results also showed that salinity stress significantly decreased the SPAD index and increased membrane permeability (Table 3). Correlation was drawn to analyze the association of different traits with cane stem height under salinity stress and found that all traits showed significant positive correlation with stem height except for ET and Na⁺, Cl⁻, CAT, APX and SOD in different plant parts (Fig. 4). Highest significant positive correlation was noted with RWC, SPAD and photosynthesis rate traits that have significant role in contributing stem height. That is, with the increase in salinity levels, the amount of antioxidants, Na⁺, and Cl⁻ significantly increased. Simultaneously, there was a notable decrease in stem length, photosynthesis rate, RWC, SPAD and stomatal conductance.

According to Norozi et al. (2019), increased salt stress can lead to the destruction of the plasma membrane due to electrolyte leakage. However, studies have shown that exogenous silicon can protect plants from this damage (Aras et al., 2020). The addition of Si fertilizer has been found to strengthen the cell membrane of plants under salt stress (Aras et al., 2020; Heile et al., 2021; Zhang et al., 2018).

Our study found that feeding sugarcane with Si fertilizer one month before applying salt stress resulted in a decrease of 18.4% in MDA levels and an increase in the activity of CAT, APX, and SOD enzymes by 36.3%, 8%, and 29.4%, respectively, compared to the control treatment (Table 6). In a study by Carvalho et al. (2016) on the effects of salinity stress on three sugarcane varieties, it was found that salinity stress increases the amount of protein, APX, and catalase (CAT) activity. The RB92579 variety was found to have a more effective mechanism in protecting the plant against reactive oxygen species (ROS).

Salinity stress has a negative impact on various aspects of sugarcane growth, including photosynthesis, stomatal conductance, SPAD, stem height, and leaf soluble proteins. Additionally, it results in an increase in the levels of Na⁺, Cl⁻, and electrolyte leakage. However, when Si fertilizer is applied, it improves all of these characteristics and prevents excessive accumulation of Na⁺ and Cl⁻, as well as electrolyte leakage (Fig. 7).

In regions with limited water resources for sugarcane irrigation, the utilization of mildly saline drainage water can still enable the production of the crop. However, this requires the use of silicon fertilizers and a willingness to accept a certain level of growth reduction. This study provides a theoretical and practical basis for evaluating the potential of Si fertilization in improving sugarcane nutrition in the absence of salinity stress in the future.

Silicon (Si); Relative Water Content (RWC); Malondialdehyde (MDA); Catalase (CAT); Ascorbate Peroxidase (APX); Superoxide Dismutase (SOD)

ACKNOWLEDGMENTS

We are grateful to Dehkhoda Sugarcane Cultivation Company in Ahvaz, Iran for generously allowing us to use their study site, personnel, and equipment for our research. We would also like to thank Alireza Shokr from the chemical laboratory at Dehkhoda Sugarcane Cultivation Company in Ahvaz, Iran. Also, we would like to express our special thanks to the Faculty of Agriculture, Shahid Chamran University of Ahvaz for the financial support (Grant number SCU.AA1401.336). Additionally, we would like to express our appreciation to Amir Moghadam, Vahid Zalghi, Maysam Jodaki, and Adel Marvani for their valuable assistance in conducting our research.

COMPETING OF INTEREST

The authors declare no conflict of interest.
ORCID

Ali Ansori Savari: https://orcid.org/0009-0006-3098-5383

Majid Nabipour: https://orcid.org/0009-0006-5488-240x

Abdelaal, K. A., EL-Maghraby, L. M., Elansary, H., Hafez, Y. M., Ibrahim, E. I., El-Banna, M., El-Esawi, M., & Elkelish, A. (2019). Treatment of sweet pepper with stress tolerance-inducing compounds alleviates salinity stress oxidative damage by mediating the physio-biochemical activities and antioxidant systems. Agronomy, 10(1), 26.
Aebi, H. (1984). [13] Catalase in vitro. In Methods in enzymology (Vol. 105, pp. 121-126). Elsevier.
Ahmad, P., Ahanger, M. A., Alam, P., Alyemeni, M. N., Wijaya, L., Ali, S., & Ashraf, M. (2019). Silicon (Si) supplementation alleviates NaCl toxicity in mung bean [Vigna radiata (L.) Wilczek] through the modifications of physio-biochemical attributes and key antioxidant enzymes. Journal of Plant Growth Regulation, 38, 70-82.
Ahmad, R., Zaheer, S. H., & Ismail, S. (1992). Role of silicon in salt tolerance of wheat (Triticum aestivum L.). Plant Science, 85(1), 43-50.
Al-Huqail, A. A., Alqarawi, A. A., Hashem, A., Malik, J. A., & Abd_Allah, E. F. (2019). Silicon supplementation modulates antioxidant system and osmolyte accumulation to balance salt stress in Acacia gerrardii Benth. Saudi Journal of Biological Sciences, 26(7), 1856-1864.
Al Murad, M., Khan, A. L., & Muneer, S. (2020). Silicon in horticultural crops: cross-talk, signaling, and tolerance mechanism under salinity stress. Plants, 9(4), 460.
Ali, M., Afzal, S., Parveen, A., Kamran, M., Javed, M. R., Abbasi, G. H., Malik, Z., Riaz, M., Ahmad, S., & Chattha, M. S. (2021). Silicon mediated improvement in the growth and ion homeostasis by decreasing Na+ uptake in maize (Zea mays L.) cultivars exposed to salinity stress. Plant Physiology and Biochemistry, 158, 208-218.
Aras, S., Keles, H., & Eşitken, A. (2020). Silicon nutrition counteracts salt-induced damage associated with changes in biochemical responses in apple. Bragantia, 79, 1-7.
Ashraf, M., Ahmad, R., Bhatti, A., Afzal, M., Sarwar, A., Maqsood, M., & Kanwal, S. (2010). Amelioration of salt stress in sugarcane (Saccharum officinarum L.) by supplying potassium and silicon in hydroponics. Pedosphere, 20(2), 153-162.
Bayer, C. (1987). Superoxide Dismutase: Improved Assays and Applicable to Acrylamide Gels. Analytical Biochemistry(44), 11.
Carvalho, M. F., Correa, M. M., Carvalho, G. C., Rolim Neto, F. C., Marinho, G., & Andrade, S. B. d. (2016). Enzymatic activity of three sugarcane varieties under salt stress. Revista Brasileira de Engenharia Agrícola e Ambiental, 20, 806-810.
Chiappero, J., del Rosario Cappellari, L., Palermo, T. B., Giordano, W., Khan, N., & Banchio, E. (2021). Antioxidant status of medicinal and aromatic plants under the influence of growth-promoting rhizobacteria and osmotic stress. Industrial Crops and Products, 167, 113541.
Conceição, S. S., Oliveira Neto, C. F. d., Marques, E. C., Barbosa, A. V. C., Galvão, J. R., Oliveira, T. B. d., Okumura, R. S., Martins, J. T. d. S., Costa, T. C., & Gomes-Filho, E. (2019). Silicon modulates the activity of antioxidant enzymes and nitrogen compounds in sunflower plants under salt stress. Archives of Agronomy and Soil Science, 65(9), 1237-1247.
Dhiman, P., Rajora, N., Bhardwaj, S., Sudhakaran, S. S., Kumar, A., Raturi, G., Chakraborty, K., Gupta, O. P., Devanna, B., & Tripathi, D. K. (2021). Fascinating role of silicon to combat salinity stress in plants: An updated overview. Plant Physiology and Biochemistry, 162, 110-123.
Dionisio-Sese, M. L., & Tobita, S. (1998). Antioxidant responses of rice seedlings to salinity stress. Plant Science, 135(1), 1-9.
Emanuil, N., Akram, M. S., Ali, S., El-Esawi, M. A., Iqbal, M., & Alyemeni, M. N. (2020). Peptone-induced physio-biochemical modulations reduce cadmium toxicity and accumulation in spinach (Spinacia oleracea L.). Plants, 9(12), 1806.
Estefan, G., Sommer, R., & Ryan, J. (2013). Methods of soil, plant, and water analysis. A manual for the West Asia and North Africa region, 3, 65-119.
Farouk, S., & Omar, M. (2020). Sweet basil growth, physiological and ultrastructural modification, and oxidative defense system under water deficit and silicon forms treatment. Journal of Plant Growth Regulation, 39, 1307-1331.
Flam-Shepherd, R., Huynh, W. Q., Coskun, D., Hamam, A. M., Britto, D. T., & Kronzucker, H. J. (2018). Membrane fluxes, bypass flows, and sodium stress in rice: the influence of silicon. Journal of Experimental Botany, 69(7), 1679-1692.
Garg, N., & Bhandari, P. (2016). Silicon nutrition and mycorrhizal inoculations improve growth, nutrient status, K+/Na+ ratio and yield of Cicer arietinum L. genotypes under salinity stress. Plant Growth Regulation, 78(3), 371-387.
Hashemi, A., Abdolzadeh, A., & Sadeghipour, H. R. (2010). Beneficial effects of silicon nutrition in alleviating salinity stress in hydroponically grown canola, Brassica napus L., plants. Soil Science & Plant Nutrition, 56(2), 244-253.
Heile, A. O., Aslam, Z., Hussain, A., Aslam, M., Saleem, M. H., Abualreesh, M. H., Alatawi, A., & Ali, S. (2021). Alleviation of cadmium phytotoxicity using silicon fertilization in wheat by altering antioxidant metabolism and osmotic adjustment. Sustainability, 13(20), 11317.
Hurtado, A. C., Chiconato, D. A., de Mello Prado, R., Junior, G. d. S. S., Viciedo, D. O., & de Cássia Piccolo, M. (2020). Silicon application induces changes C: N: P stoichiometry and enhances stoichiometric homeostasis of sorghum and sunflower plants under salt stress. Saudi Journal of Biological Sciences, 27(12), 3711-3719.
Johnson, C., Huston, R., & Ozanne, P. (1958). Plant Analyses, Measurement of Microgram Amounts of Chlorine in Plant Materials. Journal of Agricultural and Food Chemistry, 6(2), 114-118.
Ju, F., Pang, J., Huo, Y., Zhu, J., Yu, K., Sun, L., Loka, D. A., Hu, W., Zhou, Z., & Wang, S. (2021). Potassium application alleviates the negative effects of salt stress on cotton (Gossypium hirsutum L.) yield by improving the ionic homeostasis, photosynthetic capacity and carbohydrate metabolism of the leaf subtending the cotton boll. Field Crops Research, 272, 108288.
Khan, W. u. D., Aziz, T., Hussain, I., Ramzani, P. M. A., & Reichenauer, T. G. (2017). Silicon: a beneficial nutrient for maize crop to enhance photochemical efficiency of photosystem II under salt stress. Archives of Agronomy and Soil Science, 63(5), 599-611.
Maehly, A., & Chance, B. (1954). Catalases and peroxidases. Methods Biochem Anal, 1, 357-424.
Munns, R., & Tester, M. (2008). Mechanisms of salinity tolerance. Annu. Rev. Plant Biol., 59, 651-681.
Nakano, Y., & Asada, K. (1981). Hydrogen peroxide is scavenged by ascorbate-specific peroxidase in spinach chloroplasts. Plant and Cell Physiology, 22(5), 867-880.
Naveed, M., Ramzan, N., Mustafa, A., Samad, A., Niamat, B., Yaseen, M., Ahmad, Z., Hasanuzzaman, M., Sun, N., & Shi, W. (2020). Alleviation of salinity induced oxidative stress in Chenopodium quinoa by Fe biofortification and biochar—endophyte interaction. Agronomy, 10(2), 168.
Norozi, M., ValizadehKaji, B., Karimi, R., & Nikoogoftar Sedghi, M. (2019). Effects of foliar application of potassium and zinc on pistachio (Pistacia vera L.) fruit yield. International Journal of Horticultural Science and Technology, 6(1), 113-123.
Rao, G. B., & Susmitha, P. (2017). Silicon uptake, transportation and accumulation in Rice. Journal of Pharmacognosy and Phytochemistry, 6(6), 290-293.
Rizwan, M., Ali, S., Ibrahim, M., Farid, M., Adrees, M., Bharwana, S. A., Zia-ur-Rehman, M., Qayyum, M. F., & Abbas, F. (2015). Mechanisms of silicon-mediated alleviation of drought and salt stress in plants: a review. Environmental Science and Pollution Research, 22, 15416-15431.
Rohanipoor, A., Norouzi, M., Moozzi, A., & Hassibi, P. (2013). Effect of silicon on some physiological properties of maize (Zea mays) under salt stress.
Shah, T., Latif, S., Saeed, F., Ali, I., Ullah, S., Alsahli, A. A., Jan, S., & Ahmad, P. (2021). Seed priming with titanium dioxide nanoparticles enhances seed vigor, leaf water status, and antioxidant enzyme activities in maize (Zea mays L.) under salinity stress. Journal of King Saud University-Science, 33(1), 101207.
Turner, N. C., & Kramer, P. J. (1980). Adaptation of plants to water and high temperature stress.
Vasantha, S., Venkataramana, S., Gururaja Rao, P. N., & Gomathi, R. (2010). Long term salinity effect on growth, photosynthesis and osmotic characteristics in sugarcane. Sugar Tech, 12(1), 5-8. https://doi.org/10.1007/s12355-010-0002-z
Wang, M., Zheng, Q., Shen, Q., & Guo, S. (2013). The critical role of potassium in plant stress response. International Journal of Molecular Sciences, 14(4), 7370-7390.
Wu, H. (2018). Plant salt tolerance and Na+ sensing and transport. The Crop Journal, 6(3), 215-225.
Zhang, W., Yu, X., Li, M., Lang, D., Zhang, X., & Xie, Z. (2018). Silicon promotes growth and root yield of Glycyrrhiza uralensis under salt and drought stresses through enhancing osmotic adjustment and regulating antioxidant metabolism. Crop protection, 107, 1-11.
Zhang, W., Zhang, X., Lang, D., Li, M., Liu, H., & Zhang, X. (2020). Silicon alleviates salt and drought stress of Glycyrrhiza uralensis plants by improving photosynthesis and water status. Biol. Plant, 64, 302-313.
Zhao, D., Zhu, K., Momotaz, A., & Gao, X. (2020). Sugarcane plant growth and physiological responses to soil salinity during tillering and stalk elongation. Agriculture, 10(12), 608.
Zhao, S., Zhang, Q., Liu, M., Zhou, H., Ma, C., & Wang, P. (2021). Regulation of plant responses to salt stress. International Journal of Molecular Sciences, 22(9), 4609.

Download PDF

Version 1

posted

You are reading this latest preprint version

Increasing Sugarcane Salinity Resistance with Silicon Fertilizer by Preventing the Absorption of Na+ and Cl- and Improve Antioxidant Defense System

Status:

Version 1

Abstract

Figures

1. Introduction

2. Materials and Methods

2.1. Experimental Design and Treatments

2.2. Silicon fertilization

2.3. Gas exchange attributes

2.4. Water related attributes (RWC) and Electrolyte leakage (EL)

2.5. Mineral Attributes

2.6. Enzymatic antioxidants, Malondialdehyde (MDA) and Proline content

2.7. Statistical analysis

3. Results

4. Discussion

Abbreviations

Declarations

References

Status:

Version 1