Current IssueSpecial IssueEditorial BoardOnline First ArticlesArchive
Current IssueSpecial IssueEditorial BoardOnline First ArticlesArchive

Full Research Article

Reducing the Negative Effects of Hydrogen Peroxide by Spraying Zinc and Selenocysteine on Okra

R
Ruaa Abed Hassan1,*
D
Diana T. Shamkhey1
H
Hussein Aziz Mohammed1
1Department of Soil Science and Water Recourses, College of Agriculture, University of Diyala, Diyala, Iraq.

ABSTRACT

Background: The application of trace elements is important to improve plant growth under oxidative stress conditions, as foliar spraying improves plant physiology, growth and production. Aims to adding zinc to treat the harmful effect of the root Hydrogen peroxide for okra and study of the interaction between zinc and the amino acid selenocysteine in improving the plant’s ability to face hydrogen peroxide stress.

Methods: A field experiment was conducted during the spring season of 2024 at the College of Agriculture-University of Diyala. A randomized complete block design (RCBD) was used with three replicates. The experimental treatments included three levels of spraying hydrogen peroxide acid (0,3,6) mg L-1 symbolized by (H0,H3,H6) and two levels of spraying zinc element (100,0) mg Zn.L-1 symbolized by (Zn0,Zn100) and three levels of spraying amino acid selenocysteine (50,25,0) mg L-1 symbolized by (Se0,Se25, Se50). Okra plant, Iraqi Batira variety, was planted.

Result: The third treatment of spraying hydrogen peroxide led to a significant reduction in most of the studied traits. Reducing the negative effects of hydrogen peroxide on the plant by using the second level of zinc spray Zn100, as the plant height, total chlorophyll content in the leaves, number of fruits and total plant yield increased by an average of 100.56 cm, 37.90 SPAD, 9.03 fruits per plant and 94.33 Mg.h-1. Reducing the negative effects of spraying hydrogen peroxide by spraying the amino acid selenocysteine at a level of 50 mg.L-1 for most of the experimental traits. The leaf proline content was not affected by the levels of zinc and selenocysteine used, while the proline concentration increased with spraying high levels of hydrogen peroxide.

INTRODUCTION

Abiotic and biotic stresses lead to radical changes in physiological functions in plants such as production of reactive oxygen species, loss of photosynthetic efficiency, membrane damage, etc., which slows down the expansion and causes poor yield and quality (ALMafargy et al., 2020). Hydrogen peroxide (H2O2) is one of the reactive oxygen species (ROS), which can damage a variety of cellular structures when present in excess in the plant and it acts as a powerful signaling molecule that mediates various physiological and biochemical processes in plants (Al-Abbasi et al., 2023). The application of trace elements is important to improve plant growth under oxidative stress conditions, as foliar spraying improves plant physiology, growth and production. Zinc acts as a synthetic antioxidant and has a major role in stimulating enzymes. Zinc plays a vital role in the formation of auxin in plants, which helps promote growth and participates in controlling water absorption in plants (Alrawi, 2018).
       
Foliar spraying of zinc is used to enhance the production of plant resistance to stresses and it also regulates many metabolic activities in plants, including wood, sugar transport, cell wall structure and membrane permeability and protein and carbohydrate metabolism (Hashim and Mohammed, 2023). Amino acids are an important source of nitrogen and are rapidly absorbed by plants. They are an important transport vehicle for organic nitrogen in many plants. Amino acids have physiological effects on plants and their growth due to their association with several pathways in the plant. There is a link between some amino acids such as selenocysteine   and resistance to biotic stress, starch formation mechanism and protein interaction (Kordrostami et al., 2023). Selenocysteine is the twenty-first amino acid in the genetic code. It is structurally similar to cysteine (Cys) but with sulfur replaced by selenium. This simple change gives selenocysteine   (Sec) chemical properties related to cysteine (Cys). Selenocysteine (Sec) is found in selenoproteins that play various roles such as cellular maintenance, immune response, hormone regulation and complex biological oxidative stress (Mohamed et al., 2016). Okra cultivation occupies a large area in the production and marketing map in Iraq. Therefore, the study aims to adding zinc to treat the harmful effect of the root Hydrogen peroxide for okra and study of the interaction between zinc and the amino acid selenocysteine   in improving the plant’s ability to face hydrogen peroxide stress.

MATERIALS AND METHODS

The experiment was coundected during the spring season of 2024 at the research station affiliated with the Department of Horticulture and Landscape Engineering/College of Agriculture/University of Diyala. The experiment was conducted for the period from 3/1/2024 to 10/15/2024. Okra seeds of the Iraqi Batira variety were used. The agricultural land was prepared by cleaning the soil, plowing it and preparing it by making terraces with a width of 60 cm, extending two lines of drip pipes on them and planting okra seeds alternately on the terrace with a distance of 40 cm between the plants of one line, with 4 seeds per pits, thinned for one plant upon germination and extending irrigation pipes.
       
Soil samples were collected randomly and at a depth of 0-30 cm, then the samples were mixed well (Table 1). The experiment included three levels of hydrogen peroxide (0, 5, 10) symbolized by (H0, H1, H2) and two levels of spraying with zinc (100, 0) mg L-1, symbolized by (Zn0), Zn100) sprayed on the plants in the form of Zn-EDTA) and three levels of spraying with selenocysteine (0, 5, 100) mg L-1, symbolized by (Se0, Se1, 2Se). Plants were sprayed with hydrogen peroxide 15 days after germination, then they were sprayed with zinc and then with selenocysteine.

Table 1: Some chemical and physical properties of field soil before planting.


       
The chemical fertilizer K, P, N (20, 20, 20) was added with the irrigation water from During the fertilizer attached to the irrigation system in three batches, the first one week after planting, while the following batches were added with an interval of two weeks between one batch and the next from the planting date and the bushes and harmful weeds were removed whenever necessary.
       
The research was carried out as a factorial experiment according to the split-split plot design with a randomized complete block arrangement (RCBD) and with three replicates. The experimental treatments included the following: three levels of hydrogen peroxide (0, 5, 10) symbolized by (H0, H1, H2) and two levels of zinc spray (100, 0) mg L-1, symbolized by (Zn0), Zn100) sprayed on the plants in the form of Zn-EDTA (Zn13%) and three levels of selenocysteine spray (0, 5, 100) mg L-1, symbolized by (Se0, Se1, 2Se). The data were analyzed statistically according to the SPSS statistical program and the arithmetic means were compared using Duncan’s multiple-nomial test at a probability level of 0.05.
 
Studied traits
 
- The plant height was estimated using a measuring tape and the height was taken from the area of   contact of the plant stem with the soil surface to the end of the plant top when the plant growth was complete.
- The total chlorophyll content in the leaves was estimated using the SPAD-502 device manufactured.
- Proline was estimated according to the method of Mohamed et al., (2016).
- The number of fruits (fruit. plant-1) was calculated for three plants in the experimental unit and according to their average.
- The total plant yield (kg. plant-1) was calculated for three plants taken randomly from each experimental unit to take the measurement.

RESULTS AND DISCUSSION

Plant height (cm)
 
The results of the statistical analysis of Table 2 showed significant differences in the experimental factors for the plant height trait, as spraying with hydrogen peroxide at level 0 gave the highest average for the plant height trait, reaching 113.72 cm, compared to level 6, which gave the lowest average for the plant height trait, reaching 80.83 cm, while the experimental treatment of spraying with zinc at level 100 was significantly excelled with a value of 100.56 cm compared to level 0, which recorded the lowest value of 93.07 cm. As for the treatment of the amino acid selenocysteine, the spraying treatment at level 50 was significantly excelled, recording the highest value of 102.84 cm, compared to the treatment at level 0, which gave the lowest value of 90.06 cm. However, it was found that bi-interaction of the spray treatment between zinc for level 100 + selenocysteine for level 50 gave the highest value of 106.57 cm compared to the spray treatment for bi-interaction between zinc for level 0 + selenocysteine for level 0, the lowest values were recorded at 87.61 cm. As for the triple interaction, we note the presence of significant differences in the plant height trait, as the triple interaction treatment was significantly excelled among the study treatments, where the triple interaction treatment of spraying between hydrogen peroxide for level 0 + zinc for level 100 + selenocysteine for level 50 recorded the highest value of 131.45 cm compared to the spraying treatment for bi-interaction of spraying between hydrogen peroxide for level 6 + zinc for level 0 + selenocysteine for level 0, recording the lowest values of 75.07 cm.

Table 2: Treatment of the harmful effect of hydrogen peroxide by spraying zinc and the amino acid selenocysteine on the height of okra plant (cm).


 
Total chlorophyll content in leaves (SPAD)
 
The results of the statistical analysis of Table 3 showed significant differences between the experimental factors for the trait of relative chlorophyll content in leaves, where spraying with hydrogen peroxide at level 0 gave the highest average for the trait of relative chlorophyll content in leaves, reaching 38.46 SPAD compared to level 6, which achieved the lowest average for the trait, reaching 36.26 SPAD. The experimental treatment for spraying with zinc at level 100 was significantly excelled with a value of 37.90 SPAD compared to level 0, which recorded the lowest value of 36.85 SPAD, while the treatment of the amino acid selenocysteine was significantly excelled to the treatment of spraying at level 50, recording the highest value of 38.94 SPAD compared to the treatment at level 0, which gave the lowest value of 35.95 SPAD compared to the spray treatment for bi-interaction between zinc at leve l 0 + selenocystin for level 0 recorded the lowest value of 35.51 SPAD. The results of the same table for the triple interaction showed significant differences in the relative chlorophyll content in leaves, where the triple interaction treatment was significantly excelled among the study treatments, as the triple interaction treatment of spraying between hydrogen peroxide for level 0 + zinc for level 100 + selenocystin for level 50 recorded the highest value of 40.55 SPAD compared to the spraying treatment for bi-interaction of spraying between hydrogen peroxide for level 6 + zinc for level 0 + selenocystin for level 0, recording the lowest value of 34.09 SPAD.

Table 3: Treatment of the harmful effect of hydrogen peroxide by spraying zinc and the amino acid selenocystin on chlorophyll of okra plants (SPAD).


 
Proline concentration in leaves
 
The results of the statistical analysis of Table 4 showed significant differences between the experimental factors for the protein percentage trait, as spraying with hydrogen peroxide at level 6 gave the highest average for the protein percentage trait, reaching 3.18% compared to level 0, which achieved the lowest average for the trait, reaching 1.96%, while no significant differences were observed between the treatments when spraying with zinc. As for the treatment of the amino acid selenocysteine, the spraying treatment at level 0 was significantly excelled, recording the highest value of 3.33% compared to the treatment at level 50, which gave the lowest value of 1.83% compared to The spray treatment for bi-interaction between zinc for level 0 + selenocysteine   for level 50 and the spray treatment for bi-interaction between zinc for level 100 + selenocysteine   for level 50 recorded the lowest value of 1.86 and 1.80% respectively. As for the triple interaction, we note the presence of significant differences in the protein percentage, as the triple interaction treatment was significantly excelled among the study treatments, as the triple interaction treatments for spraying hydrogen peroxide for level 6 + zinc for level 0 + selenocysteine   for level 0 and the treatment between hydrogen peroxide for level 6 + zinc for level 100 + selenocysteine for level 0 recorded the highest value of 4.11 and 4.08% respectively, compared to the spray treatment for bi-interaction between hydrogen peroxide for level 0 + zinc for level 100 + selenocysteine   for level 50, recording the lowest value of 1.25%.

Table 4: Effect of treating the harmful effect of hydrogen peroxide by spraying zinc and the amino acid selenocysteine on the concentration of proline in leaves (mg.g fresh weight).


 
Number of fruits (fruit.plant-1)
 
The results of the statistical analysis of Table 5 showed significant differences between the experimental factors for the number of fruits trait, as spraying with hydrogen peroxide at level 0 gave the highest average for the number of fruits trait, reaching 11.18 fruit. plant-1 compared to level 6, which achieved the lowest average for the trait, reaching 3.31 fruit. plant-1, while the experimental treatment for spraying with zinc at level 100 was significantly excelled with a value of 9.03 fruit. plant-1 compared to level 0, which recorded the lowest value of 6.42 fruits per plant-1. As for the treatment of the amino acid selenocysteine, the spraying treatment at level 50 was significantly excelled, recording the highest value of 9.01 fruit. plant-1 compared to the treatment at level 0, which gave the lowest value of 6.67 fruit. plant-1. 

Table 5: Treatment of the harmful effect of hydrogen peroxide by spraying zinc and selenocysteine amino acid on the number of fruits of okra plant (fruit plant-1).


       
As for bi-interaction of the spray treatment between zinc at level 100 + selenocysteine   at level 50, it achieved the highest value of 11.61 fruit. plant-1compared to the spray treatments for bi-interaction between zinc at level 0 + selenocysteine at level 0, zinc spray at level 0 + selenocysteine at level 25, zinc spray at level 0 + selenocysteine at level 50 and zinc spray at level 100 + selenocysteine at level 0, recording the lowest values of 6.32, 6.53, 6.41 and 7.03 fruit. plant-1, respectively. Regarding the triple interaction, we note the presence of significant differences in the number of fruits trait, where the triple interaction treatment was significantly excelled among the study treatments, where the triple interaction treatment of spraying between hydrogen peroxide at level 0 + zinc at level 100 + selenocysteine at level 50 recorded the highest value of 19.07 fruit.plant-1 compared to the spray treatments for bi-interaction between hydrogen peroxide at level 6 + zinc at level 0 + selenocysteine at level 0, spraying hydrogen peroxide at level 6 + zinc at level 0 + selenocysteine at level 25, spraying hydrogen peroxide at level 6 + zinc at level 0 + selenocysteine   at level 50, spraying hydrogen peroxide at level 6 + zinc at level 100 + selenocysteine at level 0, spraying hydrogen peroxide at level 6 + zinc at level 100 + selenocysteine at level 25 and spraying hydrogen peroxide at level 6 + zinc at level 100 + selenocysteine at level 50 recorded the lowest value of 2.73, 3.56, 2.63, 3.10, 3.66 and 4.20 fruit.plant-1 respectively.
 
Total plant yield (Mg.ha-1)
 
The results of the statistical analysis of Table 6 showed significant differences between the experimental factors for the total plant yield trait, as spraying with hydrogen peroxide at level 0 gave the highest average for the total plant yield trait, reaching 134.00 Mg.ha-1 compared to level 6, which achieved the lowest average for the trait, reaching 39.66 Mg.ha-1. The experimental treatment for spraying with zinc at level 100 was significantly excelled with a value of 94.33 Mg.ha-1 compared to level 0, which recorded the lowest value of 80.55 Mg.ha-1, while the treatment of the amino acid selenocysteine was significantly excelled to the spraying treatment at level 50, recording the highest value of 115.72 Mg.ha-1 compared to the treatment at level 0, which gave the lowest value of 67.88 Mg.ha-1. The results of the same table for the triple interaction showed significant differences in the total plant yield trait, as the triple interaction treatment was significantly excelled among the study treatments, as the triple interaction treatment for spraying between hydrogen peroxide for level 0 + zinc for level 100 + selenocysteine for level 50 recorded the highest value of 195.00 Mg.ha-1 compared to the spray treatment for bi-interaction between hydrogen peroxide for level 6 + zinc for level 0 + selenocysteine   for level 0, recording the lowest value of 28.33 Mg.ha-1.

Table 6: Treatment of the harmful effect of hydrogen peroxide by spraying zinc and the amino acid selenocysteine on the total plant yield of okra (Mg h-1).


       
The results of the experiment showed that spraying the plant with hydrogen peroxide at a concentration of 6 mg L-1 led to a significant decrease in all the studied characteristics, as hydrogen peroxide (H2O2) is one of the reactive oxygen species (ROS), which leads to damage to the cell structure and also acts as a strong signal molecule that mediates physiological and biochemical processes in plants (Nurnaeimah et al., 2020; Li et al., 2017). Hydrogen peroxide (H2O2) is a weak acid from the ROS group that is formed inside the plant cell under natural conditions and its concentration increases when exposed to various stresses as a result of the reduction of two electrons from the oxygen molecule with the help of the enzyme superoxide dismutase (SOD). Hydrogen peroxide participates in many vital reactions and when its concentration increases, it causes oxidative damage to enzymes, membrane lipids, proteins and other cellular components, leading to cell death. It is the only free radical capable of spreading through membrane water channels (Aquaporin) and crossing longer distances inside the cell, as it is able to It causes damage in areas far from its place of production inside the cell, while at low concentrations it acts as a chemical signal transmitter that causes resistance to biotic and abiotic stresses, contributes to the growth of root hairs, wood differentiation and stomata and regulates the process of closing and opening stomata to correct plant growth and development (Rahman et al., 2020; Nagalakshmi et al., 2017).
       
Zinc has many different important physiological roles as it is an essential element in manufacturing and metabolic processes and this element has a role in the vital functions of structural molecules such as nucleic acid and an activator of metabolism and regulation of enzymes and these results are consistent with what (Rahman et al., 2024) reached when studying the effect of foliar spraying with zinc on okra yield and these results are consistent with what 10  reached when evaluating the effect of foliar spraying with zinc sulfate on okra growth and yield and also consistent with what (Singh et al., 2022) reached to evaluate the effect of foliar spraying with zinc on okra growth and yield. While spraying with the amino acid selenocysteine at a concentration of 50 mg L-1 led to a significant increase in all experimental traits, the reason for improving the yield traits may be due to the role of selenium, which is the main element of the amino acid selenocysteine, in increasing the relative water content of leaves, proline, total soluble sugars, protein, phenols, flavonoids and antioxidant enzymes. Selenium also contributes to the stability of the cell membrane and reducing the leakage of ions by enhancing the production of protective compounds and enhancing the activity of antioxidant enzymes (Nurnaeimah et al., 2020). Selenium also has vital and physiological functions in the plant, as it encourages the formation of dry matter, increases the rates of carbohydrate and starch formation and their accumulation in plastids, regulates the water balance in the plant and encourages the plant to form anti-stress hormones such as ethylene, jasmonic and salicylic acids, which leads to an increase in the diameter and length of the fruit and thus an increase in its weight (Alrawi, 2018; Muñoz-Salinas et al., 2021).

CONCLUSION

The study concludes that spraying hydrogen peroxide led to a significant reduction in most of the studied traits. Reducing the negative effects of hydrogen peroxide on the plant by using the second level of zinc spray Zn100, as the plant height, total chlorophyll content in the leaves, number of fruits and total plant yield have increased.

CONFLICT OF INTEREST

The authors declare that there is no conflict of interest.

REFERENCES


  1. Al-Abbasi , A.A.A.,  Abrahium ,N.S. and Mohammed , H.A. (2023). Effect of spraying with zinc and ascorbic acid on some antioxidants of maiz (Zea mays L.) affected by heat shocks. Iop Conference. 1225(1): 012073.

  2. ALMafargy, O.K., Mohammed, H.A. and Omar, D.G. (2020). The spraying effect of zinc and salicylic acid and their comdination on the growth and production of cherryto mato. Plant Avchives. 20(1): 2349-2354.

  3. Alrawi, A. (2018). Effect of foliar application with potassium and zinc on growth, pod yield and seed production of okra. Iraqi Journal of Agricultural Sciences. 49(6): 1041-1048.

  4. Hashim, B.A, Mohammed, H.A. (2023). Effect of spraying potassium and selenium on the vegetative growth characteristics of bean plant (Phaseolus vulgares L.) affected by water stress. Iop Conference Series: Earth and Environmental Science. 1262(8): 082016.

  5. Kordrostami, M., Ghasemi-Soloklui, A.A., Hossain, M.A. and Mostofa, M.G. (2023). Breaking barriers: Selenium and silicon-mediated strategies for mitigating abiotic stress in plants. Phyton. 92(9): 0031-9457.

  6. Li, J., Li, Q., Wei, G., Zhang, J. and Li, Y. (2017). Effects of negative pressure on boar semen quality during liquid storage at 17°C. Indian Journal of Animal Research. 52(8): 1146-1150. doi: 10.18805/ijar.B-791.

  7. Muñoz-Salinas, F., Tovar-Pérez, E.G., Guevara-González, R.G., Loarca-Piña, G.F. and Torres-Pacheco, I. (2021). Effect of hydrogen peroxide pretreatment on physiological and biochemical variables during germination of alfalfa seeds. Legume Research. 44(12): 1506-1511. doi: 10.18805/LRF-646.

  8. Mohamed, M.A.A., Abd El-khalek, A.F., Elmehrat, H.G. and Mahmoud, G.A. (2016). Nitric oxide, oxalic acid and hydrogen peroxide treatments to reduce decay and maintain postharvest quality of ‘Valencia’orange fruits during cold storage. Egypt. J. Hortic. 43(1): 137-161.

  9. Nagalakshmi, D., Sridhar, K., Satyanarayana, M., Ramulu, P.S., Narwade, V.S. and Vikram L. (2017). Effect of replacing inorganic zinc with a lower level of organic zinc (zinc propionate) on performance, biochemical constituents, antioxidant, immune and mineral status in buffalo calves. Indian Journal of Animal Research. 52(9): 1292-1297. doi: 10.18805/ijar.B-3362.

  10. Nurnaeimah, N., Mat, N., Suryati Mohd, K., Badaluddin, N.A., Yusoff, N., Sajili, M.H. and Khandaker, M.M. (2020). The effects of hydrogen peroxide on plant growth, mineral accumulation, as well as biological and chemical properties of Ficus deltoidea. Agronomy. 10(4): 599.

  11. Rahman, M.H., Quddus, M.A., Satter, M.A., Ali, M.R., Sarker, M.H. and Trina, T.N. (2020). Impact of foliar application of boron and zinc on growth, quality and seed yield of Okra. Journal of Energy and Natural Resources. 9(1): 1-9.

  12. Rahman, S., Mehta, S. and Hussain, A. (2024). Use of Amino Acids in Plant Growth, Photosynthesis and Nutrient Availability. In Biostimulants in plant protection and performance. Elsevier. pp (117-127).

  13. Singh, D., Bahadur, A., Singh, A.K., Singh, H.K., Yadav, S. and Singh, D.R. (2022). Effect of zinc and boron foliar application on growth, biomass production and yields of spring-summer okra: Zinc and boron foliar yields of spring-summer okra. Journal of Agri. Search. 9(1): 46-49.
Published In
Agricultural Science Digest
Article Metrics
Metrics Icon
31
Views
0
Citations
Reviewed By
Share Article
Download Article
In this Article
    Contact us
    Follow us

    Full Research Article

    Reducing the Negative Effects of Hydrogen Peroxide by Spraying Zinc and Selenocysteine on Okra

    R
    Ruaa Abed Hassan1,*
    D
    Diana T. Shamkhey1
    H
    Hussein Aziz Mohammed1
    1Department of Soil Science and Water Recourses, College of Agriculture, University of Diyala, Diyala, Iraq.

    ABSTRACT

    Background: The application of trace elements is important to improve plant growth under oxidative stress conditions, as foliar spraying improves plant physiology, growth and production. Aims to adding zinc to treat the harmful effect of the root Hydrogen peroxide for okra and study of the interaction between zinc and the amino acid selenocysteine in improving the plant’s ability to face hydrogen peroxide stress.

    Methods: A field experiment was conducted during the spring season of 2024 at the College of Agriculture-University of Diyala. A randomized complete block design (RCBD) was used with three replicates. The experimental treatments included three levels of spraying hydrogen peroxide acid (0,3,6) mg L-1 symbolized by (H0,H3,H6) and two levels of spraying zinc element (100,0) mg Zn.L-1 symbolized by (Zn0,Zn100) and three levels of spraying amino acid selenocysteine (50,25,0) mg L-1 symbolized by (Se0,Se25, Se50). Okra plant, Iraqi Batira variety, was planted.

    Result: The third treatment of spraying hydrogen peroxide led to a significant reduction in most of the studied traits. Reducing the negative effects of hydrogen peroxide on the plant by using the second level of zinc spray Zn100, as the plant height, total chlorophyll content in the leaves, number of fruits and total plant yield increased by an average of 100.56 cm, 37.90 SPAD, 9.03 fruits per plant and 94.33 Mg.h-1. Reducing the negative effects of spraying hydrogen peroxide by spraying the amino acid selenocysteine at a level of 50 mg.L-1 for most of the experimental traits. The leaf proline content was not affected by the levels of zinc and selenocysteine used, while the proline concentration increased with spraying high levels of hydrogen peroxide.

    INTRODUCTION

    Abiotic and biotic stresses lead to radical changes in physiological functions in plants such as production of reactive oxygen species, loss of photosynthetic efficiency, membrane damage, etc., which slows down the expansion and causes poor yield and quality (ALMafargy et al., 2020). Hydrogen peroxide (H2O2) is one of the reactive oxygen species (ROS), which can damage a variety of cellular structures when present in excess in the plant and it acts as a powerful signaling molecule that mediates various physiological and biochemical processes in plants (Al-Abbasi et al., 2023). The application of trace elements is important to improve plant growth under oxidative stress conditions, as foliar spraying improves plant physiology, growth and production. Zinc acts as a synthetic antioxidant and has a major role in stimulating enzymes. Zinc plays a vital role in the formation of auxin in plants, which helps promote growth and participates in controlling water absorption in plants (Alrawi, 2018).
           
    Foliar spraying of zinc is used to enhance the production of plant resistance to stresses and it also regulates many metabolic activities in plants, including wood, sugar transport, cell wall structure and membrane permeability and protein and carbohydrate metabolism (Hashim and Mohammed, 2023). Amino acids are an important source of nitrogen and are rapidly absorbed by plants. They are an important transport vehicle for organic nitrogen in many plants. Amino acids have physiological effects on plants and their growth due to their association with several pathways in the plant. There is a link between some amino acids such as selenocysteine   and resistance to biotic stress, starch formation mechanism and protein interaction (Kordrostami et al., 2023). Selenocysteine is the twenty-first amino acid in the genetic code. It is structurally similar to cysteine (Cys) but with sulfur replaced by selenium. This simple change gives selenocysteine   (Sec) chemical properties related to cysteine (Cys). Selenocysteine (Sec) is found in selenoproteins that play various roles such as cellular maintenance, immune response, hormone regulation and complex biological oxidative stress (Mohamed et al., 2016). Okra cultivation occupies a large area in the production and marketing map in Iraq. Therefore, the study aims to adding zinc to treat the harmful effect of the root Hydrogen peroxide for okra and study of the interaction between zinc and the amino acid selenocysteine   in improving the plant’s ability to face hydrogen peroxide stress.

    MATERIALS AND METHODS

    The experiment was coundected during the spring season of 2024 at the research station affiliated with the Department of Horticulture and Landscape Engineering/College of Agriculture/University of Diyala. The experiment was conducted for the period from 3/1/2024 to 10/15/2024. Okra seeds of the Iraqi Batira variety were used. The agricultural land was prepared by cleaning the soil, plowing it and preparing it by making terraces with a width of 60 cm, extending two lines of drip pipes on them and planting okra seeds alternately on the terrace with a distance of 40 cm between the plants of one line, with 4 seeds per pits, thinned for one plant upon germination and extending irrigation pipes.
           
    Soil samples were collected randomly and at a depth of 0-30 cm, then the samples were mixed well (Table 1). The experiment included three levels of hydrogen peroxide (0, 5, 10) symbolized by (H0, H1, H2) and two levels of spraying with zinc (100, 0) mg L-1, symbolized by (Zn0), Zn100) sprayed on the plants in the form of Zn-EDTA) and three levels of spraying with selenocysteine (0, 5, 100) mg L-1, symbolized by (Se0, Se1, 2Se). Plants were sprayed with hydrogen peroxide 15 days after germination, then they were sprayed with zinc and then with selenocysteine.

    Table 1: Some chemical and physical properties of field soil before planting.


           
    The chemical fertilizer K, P, N (20, 20, 20) was added with the irrigation water from During the fertilizer attached to the irrigation system in three batches, the first one week after planting, while the following batches were added with an interval of two weeks between one batch and the next from the planting date and the bushes and harmful weeds were removed whenever necessary.
           
    The research was carried out as a factorial experiment according to the split-split plot design with a randomized complete block arrangement (RCBD) and with three replicates. The experimental treatments included the following: three levels of hydrogen peroxide (0, 5, 10) symbolized by (H0, H1, H2) and two levels of zinc spray (100, 0) mg L-1, symbolized by (Zn0), Zn100) sprayed on the plants in the form of Zn-EDTA (Zn13%) and three levels of selenocysteine spray (0, 5, 100) mg L-1, symbolized by (Se0, Se1, 2Se). The data were analyzed statistically according to the SPSS statistical program and the arithmetic means were compared using Duncan’s multiple-nomial test at a probability level of 0.05.
     
    Studied traits
     
    - The plant height was estimated using a measuring tape and the height was taken from the area of   contact of the plant stem with the soil surface to the end of the plant top when the plant growth was complete.
    - The total chlorophyll content in the leaves was estimated using the SPAD-502 device manufactured.
    - Proline was estimated according to the method of Mohamed et al., (2016).
    - The number of fruits (fruit. plant-1) was calculated for three plants in the experimental unit and according to their average.
    - The total plant yield (kg. plant-1) was calculated for three plants taken randomly from each experimental unit to take the measurement.

    RESULTS AND DISCUSSION

    Plant height (cm)
     
    The results of the statistical analysis of Table 2 showed significant differences in the experimental factors for the plant height trait, as spraying with hydrogen peroxide at level 0 gave the highest average for the plant height trait, reaching 113.72 cm, compared to level 6, which gave the lowest average for the plant height trait, reaching 80.83 cm, while the experimental treatment of spraying with zinc at level 100 was significantly excelled with a value of 100.56 cm compared to level 0, which recorded the lowest value of 93.07 cm. As for the treatment of the amino acid selenocysteine, the spraying treatment at level 50 was significantly excelled, recording the highest value of 102.84 cm, compared to the treatment at level 0, which gave the lowest value of 90.06 cm. However, it was found that bi-interaction of the spray treatment between zinc for level 100 + selenocysteine for level 50 gave the highest value of 106.57 cm compared to the spray treatment for bi-interaction between zinc for level 0 + selenocysteine for level 0, the lowest values were recorded at 87.61 cm. As for the triple interaction, we note the presence of significant differences in the plant height trait, as the triple interaction treatment was significantly excelled among the study treatments, where the triple interaction treatment of spraying between hydrogen peroxide for level 0 + zinc for level 100 + selenocysteine for level 50 recorded the highest value of 131.45 cm compared to the spraying treatment for bi-interaction of spraying between hydrogen peroxide for level 6 + zinc for level 0 + selenocysteine for level 0, recording the lowest values of 75.07 cm.

    Table 2: Treatment of the harmful effect of hydrogen peroxide by spraying zinc and the amino acid selenocysteine on the height of okra plant (cm).


     
    Total chlorophyll content in leaves (SPAD)
     
    The results of the statistical analysis of Table 3 showed significant differences between the experimental factors for the trait of relative chlorophyll content in leaves, where spraying with hydrogen peroxide at level 0 gave the highest average for the trait of relative chlorophyll content in leaves, reaching 38.46 SPAD compared to level 6, which achieved the lowest average for the trait, reaching 36.26 SPAD. The experimental treatment for spraying with zinc at level 100 was significantly excelled with a value of 37.90 SPAD compared to level 0, which recorded the lowest value of 36.85 SPAD, while the treatment of the amino acid selenocysteine was significantly excelled to the treatment of spraying at level 50, recording the highest value of 38.94 SPAD compared to the treatment at level 0, which gave the lowest value of 35.95 SPAD compared to the spray treatment for bi-interaction between zinc at leve l 0 + selenocystin for level 0 recorded the lowest value of 35.51 SPAD. The results of the same table for the triple interaction showed significant differences in the relative chlorophyll content in leaves, where the triple interaction treatment was significantly excelled among the study treatments, as the triple interaction treatment of spraying between hydrogen peroxide for level 0 + zinc for level 100 + selenocystin for level 50 recorded the highest value of 40.55 SPAD compared to the spraying treatment for bi-interaction of spraying between hydrogen peroxide for level 6 + zinc for level 0 + selenocystin for level 0, recording the lowest value of 34.09 SPAD.

    Table 3: Treatment of the harmful effect of hydrogen peroxide by spraying zinc and the amino acid selenocystin on chlorophyll of okra plants (SPAD).


     
    Proline concentration in leaves
     
    The results of the statistical analysis of Table 4 showed significant differences between the experimental factors for the protein percentage trait, as spraying with hydrogen peroxide at level 6 gave the highest average for the protein percentage trait, reaching 3.18% compared to level 0, which achieved the lowest average for the trait, reaching 1.96%, while no significant differences were observed between the treatments when spraying with zinc. As for the treatment of the amino acid selenocysteine, the spraying treatment at level 0 was significantly excelled, recording the highest value of 3.33% compared to the treatment at level 50, which gave the lowest value of 1.83% compared to The spray treatment for bi-interaction between zinc for level 0 + selenocysteine   for level 50 and the spray treatment for bi-interaction between zinc for level 100 + selenocysteine   for level 50 recorded the lowest value of 1.86 and 1.80% respectively. As for the triple interaction, we note the presence of significant differences in the protein percentage, as the triple interaction treatment was significantly excelled among the study treatments, as the triple interaction treatments for spraying hydrogen peroxide for level 6 + zinc for level 0 + selenocysteine   for level 0 and the treatment between hydrogen peroxide for level 6 + zinc for level 100 + selenocysteine for level 0 recorded the highest value of 4.11 and 4.08% respectively, compared to the spray treatment for bi-interaction between hydrogen peroxide for level 0 + zinc for level 100 + selenocysteine   for level 50, recording the lowest value of 1.25%.

    Table 4: Effect of treating the harmful effect of hydrogen peroxide by spraying zinc and the amino acid selenocysteine on the concentration of proline in leaves (mg.g fresh weight).


     
    Number of fruits (fruit.plant-1)
     
    The results of the statistical analysis of Table 5 showed significant differences between the experimental factors for the number of fruits trait, as spraying with hydrogen peroxide at level 0 gave the highest average for the number of fruits trait, reaching 11.18 fruit. plant-1 compared to level 6, which achieved the lowest average for the trait, reaching 3.31 fruit. plant-1, while the experimental treatment for spraying with zinc at level 100 was significantly excelled with a value of 9.03 fruit. plant-1 compared to level 0, which recorded the lowest value of 6.42 fruits per plant-1. As for the treatment of the amino acid selenocysteine, the spraying treatment at level 50 was significantly excelled, recording the highest value of 9.01 fruit. plant-1 compared to the treatment at level 0, which gave the lowest value of 6.67 fruit. plant-1. 

    Table 5: Treatment of the harmful effect of hydrogen peroxide by spraying zinc and selenocysteine amino acid on the number of fruits of okra plant (fruit plant-1).


           
    As for bi-interaction of the spray treatment between zinc at level 100 + selenocysteine   at level 50, it achieved the highest value of 11.61 fruit. plant-1compared to the spray treatments for bi-interaction between zinc at level 0 + selenocysteine at level 0, zinc spray at level 0 + selenocysteine at level 25, zinc spray at level 0 + selenocysteine at level 50 and zinc spray at level 100 + selenocysteine at level 0, recording the lowest values of 6.32, 6.53, 6.41 and 7.03 fruit. plant-1, respectively. Regarding the triple interaction, we note the presence of significant differences in the number of fruits trait, where the triple interaction treatment was significantly excelled among the study treatments, where the triple interaction treatment of spraying between hydrogen peroxide at level 0 + zinc at level 100 + selenocysteine at level 50 recorded the highest value of 19.07 fruit.plant-1 compared to the spray treatments for bi-interaction between hydrogen peroxide at level 6 + zinc at level 0 + selenocysteine at level 0, spraying hydrogen peroxide at level 6 + zinc at level 0 + selenocysteine at level 25, spraying hydrogen peroxide at level 6 + zinc at level 0 + selenocysteine   at level 50, spraying hydrogen peroxide at level 6 + zinc at level 100 + selenocysteine at level 0, spraying hydrogen peroxide at level 6 + zinc at level 100 + selenocysteine at level 25 and spraying hydrogen peroxide at level 6 + zinc at level 100 + selenocysteine at level 50 recorded the lowest value of 2.73, 3.56, 2.63, 3.10, 3.66 and 4.20 fruit.plant-1 respectively.
     
    Total plant yield (Mg.ha-1)
     
    The results of the statistical analysis of Table 6 showed significant differences between the experimental factors for the total plant yield trait, as spraying with hydrogen peroxide at level 0 gave the highest average for the total plant yield trait, reaching 134.00 Mg.ha-1 compared to level 6, which achieved the lowest average for the trait, reaching 39.66 Mg.ha-1. The experimental treatment for spraying with zinc at level 100 was significantly excelled with a value of 94.33 Mg.ha-1 compared to level 0, which recorded the lowest value of 80.55 Mg.ha-1, while the treatment of the amino acid selenocysteine was significantly excelled to the spraying treatment at level 50, recording the highest value of 115.72 Mg.ha-1 compared to the treatment at level 0, which gave the lowest value of 67.88 Mg.ha-1. The results of the same table for the triple interaction showed significant differences in the total plant yield trait, as the triple interaction treatment was significantly excelled among the study treatments, as the triple interaction treatment for spraying between hydrogen peroxide for level 0 + zinc for level 100 + selenocysteine for level 50 recorded the highest value of 195.00 Mg.ha-1 compared to the spray treatment for bi-interaction between hydrogen peroxide for level 6 + zinc for level 0 + selenocysteine   for level 0, recording the lowest value of 28.33 Mg.ha-1.

    Table 6: Treatment of the harmful effect of hydrogen peroxide by spraying zinc and the amino acid selenocysteine on the total plant yield of okra (Mg h-1).


           
    The results of the experiment showed that spraying the plant with hydrogen peroxide at a concentration of 6 mg L-1 led to a significant decrease in all the studied characteristics, as hydrogen peroxide (H2O2) is one of the reactive oxygen species (ROS), which leads to damage to the cell structure and also acts as a strong signal molecule that mediates physiological and biochemical processes in plants (Nurnaeimah et al., 2020; Li et al., 2017). Hydrogen peroxide (H2O2) is a weak acid from the ROS group that is formed inside the plant cell under natural conditions and its concentration increases when exposed to various stresses as a result of the reduction of two electrons from the oxygen molecule with the help of the enzyme superoxide dismutase (SOD). Hydrogen peroxide participates in many vital reactions and when its concentration increases, it causes oxidative damage to enzymes, membrane lipids, proteins and other cellular components, leading to cell death. It is the only free radical capable of spreading through membrane water channels (Aquaporin) and crossing longer distances inside the cell, as it is able to It causes damage in areas far from its place of production inside the cell, while at low concentrations it acts as a chemical signal transmitter that causes resistance to biotic and abiotic stresses, contributes to the growth of root hairs, wood differentiation and stomata and regulates the process of closing and opening stomata to correct plant growth and development (Rahman et al., 2020; Nagalakshmi et al., 2017).
           
    Zinc has many different important physiological roles as it is an essential element in manufacturing and metabolic processes and this element has a role in the vital functions of structural molecules such as nucleic acid and an activator of metabolism and regulation of enzymes and these results are consistent with what (Rahman et al., 2024) reached when studying the effect of foliar spraying with zinc on okra yield and these results are consistent with what 10  reached when evaluating the effect of foliar spraying with zinc sulfate on okra growth and yield and also consistent with what (Singh et al., 2022) reached to evaluate the effect of foliar spraying with zinc on okra growth and yield. While spraying with the amino acid selenocysteine at a concentration of 50 mg L-1 led to a significant increase in all experimental traits, the reason for improving the yield traits may be due to the role of selenium, which is the main element of the amino acid selenocysteine, in increasing the relative water content of leaves, proline, total soluble sugars, protein, phenols, flavonoids and antioxidant enzymes. Selenium also contributes to the stability of the cell membrane and reducing the leakage of ions by enhancing the production of protective compounds and enhancing the activity of antioxidant enzymes (Nurnaeimah et al., 2020). Selenium also has vital and physiological functions in the plant, as it encourages the formation of dry matter, increases the rates of carbohydrate and starch formation and their accumulation in plastids, regulates the water balance in the plant and encourages the plant to form anti-stress hormones such as ethylene, jasmonic and salicylic acids, which leads to an increase in the diameter and length of the fruit and thus an increase in its weight (Alrawi, 2018; Muñoz-Salinas et al., 2021).

    CONCLUSION

    The study concludes that spraying hydrogen peroxide led to a significant reduction in most of the studied traits. Reducing the negative effects of hydrogen peroxide on the plant by using the second level of zinc spray Zn100, as the plant height, total chlorophyll content in the leaves, number of fruits and total plant yield have increased.

    CONFLICT OF INTEREST

    The authors declare that there is no conflict of interest.

    REFERENCES


    1. Al-Abbasi , A.A.A.,  Abrahium ,N.S. and Mohammed , H.A. (2023). Effect of spraying with zinc and ascorbic acid on some antioxidants of maiz (Zea mays L.) affected by heat shocks. Iop Conference. 1225(1): 012073.

    2. ALMafargy, O.K., Mohammed, H.A. and Omar, D.G. (2020). The spraying effect of zinc and salicylic acid and their comdination on the growth and production of cherryto mato. Plant Avchives. 20(1): 2349-2354.

    3. Alrawi, A. (2018). Effect of foliar application with potassium and zinc on growth, pod yield and seed production of okra. Iraqi Journal of Agricultural Sciences. 49(6): 1041-1048.

    4. Hashim, B.A, Mohammed, H.A. (2023). Effect of spraying potassium and selenium on the vegetative growth characteristics of bean plant (Phaseolus vulgares L.) affected by water stress. Iop Conference Series: Earth and Environmental Science. 1262(8): 082016.

    5. Kordrostami, M., Ghasemi-Soloklui, A.A., Hossain, M.A. and Mostofa, M.G. (2023). Breaking barriers: Selenium and silicon-mediated strategies for mitigating abiotic stress in plants. Phyton. 92(9): 0031-9457.

    6. Li, J., Li, Q., Wei, G., Zhang, J. and Li, Y. (2017). Effects of negative pressure on boar semen quality during liquid storage at 17°C. Indian Journal of Animal Research. 52(8): 1146-1150. doi: 10.18805/ijar.B-791.

    7. Muñoz-Salinas, F., Tovar-Pérez, E.G., Guevara-González, R.G., Loarca-Piña, G.F. and Torres-Pacheco, I. (2021). Effect of hydrogen peroxide pretreatment on physiological and biochemical variables during germination of alfalfa seeds. Legume Research. 44(12): 1506-1511. doi: 10.18805/LRF-646.

    8. Mohamed, M.A.A., Abd El-khalek, A.F., Elmehrat, H.G. and Mahmoud, G.A. (2016). Nitric oxide, oxalic acid and hydrogen peroxide treatments to reduce decay and maintain postharvest quality of ‘Valencia’orange fruits during cold storage. Egypt. J. Hortic. 43(1): 137-161.

    9. Nagalakshmi, D., Sridhar, K., Satyanarayana, M., Ramulu, P.S., Narwade, V.S. and Vikram L. (2017). Effect of replacing inorganic zinc with a lower level of organic zinc (zinc propionate) on performance, biochemical constituents, antioxidant, immune and mineral status in buffalo calves. Indian Journal of Animal Research. 52(9): 1292-1297. doi: 10.18805/ijar.B-3362.

    10. Nurnaeimah, N., Mat, N., Suryati Mohd, K., Badaluddin, N.A., Yusoff, N., Sajili, M.H. and Khandaker, M.M. (2020). The effects of hydrogen peroxide on plant growth, mineral accumulation, as well as biological and chemical properties of Ficus deltoidea. Agronomy. 10(4): 599.

    11. Rahman, M.H., Quddus, M.A., Satter, M.A., Ali, M.R., Sarker, M.H. and Trina, T.N. (2020). Impact of foliar application of boron and zinc on growth, quality and seed yield of Okra. Journal of Energy and Natural Resources. 9(1): 1-9.

    12. Rahman, S., Mehta, S. and Hussain, A. (2024). Use of Amino Acids in Plant Growth, Photosynthesis and Nutrient Availability. In Biostimulants in plant protection and performance. Elsevier. pp (117-127).

    13. Singh, D., Bahadur, A., Singh, A.K., Singh, H.K., Yadav, S. and Singh, D.R. (2022). Effect of zinc and boron foliar application on growth, biomass production and yields of spring-summer okra: Zinc and boron foliar yields of spring-summer okra. Journal of Agri. Search. 9(1): 46-49.
    In this Article
      Contact us
      Follow us
      Published In
      Agricultural Science Digest

      Editorial Board

      View all (0)