Exogenous potassium nitrate alleviates salt-induced oxidative stress in maize

  • Ali Doğru Sakarya University Faculty of Arts and Science Department of Biology, Esentepe, 54187 Sakarya, Turkey
  • Ecenur Demirtaş Sakarya University Faculty of Arts and Science Department of Biology, Esentepe, 54187 Sakarya, Turkey
Keywords: Antioxidant enzymes, Maize, Potassium nitrate, Salinity, Salt tolerance


The effects of the exogenous potassium nitrate application on major antioxidant enzymes, photosynthetic pigment content, malondialdehyde, hydrogen peroxide and free proline were investigated in salt-stressed (75 mM NaCl) maize genotype (ADA 9510). Plants were grown in growth chamber for ten days. After five days of applications (control, 0 mM NaCl), S75 (75 mM NaCl), potassium nitrate (3 mM KNO3) and S75 + potassium nitrate (75 mM NaCl + 3 mM KNO3), plants were harvested. The results showed that salt stress significantly decreased chlorophyll a, chlorophyll b and total chlorophyll contents and increased the activities of superoxide dismutase, ascorbate peroxidase and glutathione reductase. Malondialdehyde, hydrogen peroxide and free proline contents were increased by salt stress. These results showed that salinity led to the oxidative stress and destruction of photosynthetic pigments in maize leaves. The exogenous potassium nitrate application, on the other hand, caused to the increased chlorophyll a, chlorophyll b, total chlorophyll and total carotenoid, elevated level of ascorbate peroxidase and glutathione reductase, and decreased malondialdehyde, hydrogen peroxide and free proline content. This kind of changes may indicate that the exogenous potassium nitrate application activates the antioxidant defence system and counteract the oxidative stress. Thus, it may be concluded that the exogenous potassium nitrate application improves salt tolerance and encourage the growth of maize plants under salt stress at early seedling stage.

DOI: http://dx.doi.org/10.5281/zenodo.4245196


Download data is not yet available.


1. Doğru A, Çakırlar H. Is leaf age a predictor for cold tolerance in winter oilseed rape plants? Func Plant Biol. 2020; 47: 250-262.

2. Doğru A, Çakırlar H. Effects of leaf age on chlorophyll fluorescence and antioxidant enzymes in winter rapeseeds leaves under cold acclimation conditions. Brazil J Bot. 2020; 43: 11-20.

3. Lin Y, Liu Z, Shi Q, Wang X, Wei M, Yang F. Exogenous nitric oxide (NO) increased antioxidant capacity of cucumber hypocotyl and radicle under salt stress. Sci Hort. 2012; 142: 118-127.

4. Doğru A, Yılmaz Kaçar M. A preliminary study on salt tolerance of some barley genotypes. Saudi J Sci. 2019; 23: 755-762.

5. Khalid MN, Iqbal HF, Tahir A, Ahmad AN. Germination potential of chickpeas (Cicer arietinum L.) under saline conditions. Pak J Bot. 2001; 4: 395-396.

6. Ashraf M. Salt tolerance of cotton: some new advances. Crit Rev Plant Sci. 2002; 21: 1-30.

7. Munns R. Comparative physiology of salt and water stress. Plant Cell Environ. 2002; 33: 453-467.

8. Ashraf M, Athar HR, Harris PJC, Kwon TR. Some prospective strategies for improving crop salt tolerance. Adv Agron. 2008; 97: 45-110.

9. Wang M, Zheng Q, Shen Q, Guo S. The critical role of potassium in plant stress response. Int J Mol Sci. 2013; 14: 7370-7390.

10. Dawood MG, Abdelhamid MD, Schmidhalter U. Potassium fertilizers enhances the salt tolerance of common bean (Phaseolus vulgaris L.). J Hort Sci Biotechnol. 2014; 89: 185-192.

11. Ashraf M, Ahmad RR, Bhatti AS, Afzal M, Sarwar A, Maqsood MA, Kanwal S. Amelioration of salt stress in sugarcane (Saccharum officinarum L.) by supplying potassium and silicon in hydroponics. Pedosphere. 2010; 20: 153-162.

12. Chakraborty K, Bhaduri D, Meena HN, Kalariya K. External potassium (K+) application improves salinity tolerance by promoting Na+-exclusion, K+-accumulation and osmotic adjustment in contrasting peanut cultivars. Plant Physiol Biochem. 2016; 103: 143-153.

13. Kaya C, Tuna AL, Ashraf M, Altunlu A. Improved salt tolerance of melon (Cucumis melo L.) by the addition of proline and potassium nitrate. Env Exp Bot. 2007; 60: 397-403.

14. Marques DJ, Broetto F, Ferreira MM, Lobato AKDS, Awila FWD, Pereira FJ. Effect of potassium sources on the antioxidant activity of eggplant. Rev Bras Cien Solo. 2014; 38: 1836-1842.

15. Seçkin B, Türkan İ, Sekmen AH, Özfidan C. The role of antioxidant defence system at differential salt tolerance of Hordeum marinum Huds. (sea barleygrass) and Hordeum vulgare L. (cultivated barley). Env Exp Bot. 2010; 69: 76-85.

16. Lichtenthaler H. Chlorophylls and carotenoids: pigments of photosynthetic membranes. Meth Enzymol. 1987; 148: 350-382.

17. Heath RL, Packer L. Photoperoxidation in isolated chloroplasts I. Kinetic and stoichiometry of fatty acid peroxidation. Arch Biochem Biophys. 1968; 125: 189-198.

18. Ohkawa H, Ohishi N, Yagi NY. Assay of lipid peroxides in animal tissue by thiobarbituric acid reaction. Anal Biochem. 1979; 95: 351-358.

19. Bates LS, Waldren RP, Teare ID. Rapid determination of free proline for water-stress studies. Plant Soil. 1973; 39: 205-207.

20. Bradford MM. A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Anal Biochem. 1976; 72: 248-254.

21. Beyer WF, Fridovich I. Assaying for superoxide dismutase activity: Some large consequences of minor changes in conditions. Anal Biochem. 1987; 161: 559-566.

22. Wang SY, Jiao H, Faust M. Changes in ascorbate, glutathione and related enzyme activity during thidiazuron-induced bud break of apple. Plant Physiol. 1991; 82: 231-236.

23. Sgherri CLM, Loggini B, Puliga S, Navari-Izzo F. Antioxidant system in Sporobolus stapfianus: changes in response to desiccation and rehydration. Phytochem. 1994; 35: 561-565.

24. Ahanger MA, Agarwal RM. Salinity stress induced alterations in antioxidant metabolism and nitrogen assimilation in wheat (Triticum aestivum L.) as influenced by potassium supplementation. Plant Physiol Biochem. 2017; 115: 449-460.

25. Shabala S, Pottosin I. Regulation of potassium transport in plants under hostile conditions: implication for abiotic and biotic stress tolerance. Physiol Plant. 2014; 151: 257-279.

26. Ahmad P, Jhon R. Effect of salt stress on growth and biochemical parameters of Pisum sativum L. Arch Agron Soil Sci. 2005; 51: 665-672.

27. Anuradha S, Rao SSR. Application of brassinosteroids in rice seeds (Oryza sativa L.) reduced the impact of salt stress on growth and improved photosynthetic pigment levels and nitrate reductase activity. Plant Growth Regul. 2003; 40: 29-32.

28. Al-Aghabary K, Zhu Z, Qinhua S. Influence of silicon supply on chlorophyll content, chlorophyll fluorescence and antioxidative enzyme activities on tomato plants under salt stress. J. Plant Nutr. 2004; 27: 2101-2115.

29. Bybordi A. Effect of ascorbic acid and silicium on photosynthesis, antioxidant enzyme activity, and fatty acid contents in canola exposure to salt stress. J Int Agric. 2012; 11: 1610-1620.

30. Taibi K, Taibi F, Abderrahim LA, Annejah A, Belkhodja M, Mule J.M. Effect of salt stress on growth, chlorophyll content, lipid peroxidation and antioxidant defence system in Phaseolus vulgaris L. South Afr J Bot. 2016; 105: 306-312.

31. Dalal VK, Tripaty BC. Modulation of chlorophyll biosynthesis by water stress in rice seedlings during chloroplast biogenesis. Plant Cell Environ. 2012; 35: 1685-1703.

32. Jain M, Mittal M, Gadre R. Effect of PEG-6000 imposed water deficit on chlorophyll metabolism in maize leaves. J Stress Physiol Biochem. 2013; 9: 262-271.

33. Dolatabadian A, Jouneghani S. Impact of exogenous ascorbic acid on antioxidant activity and some physiological traits of common bean subjected to salinity stress. Not Bot Hort Agrobot Cluj. 2009; 37: 165-172.

34. Hussein M, Mehanna H, Zaki S, Hay NFA. Influences of salt stress and foliar fertilizers on growth, chlorophyll and carotenoids of jojoba plants. Middle East J Agric Res. 2014; 3: 221-226.

35. Fayez KA, Bazaid SA. Improving drought and salinity tolerance in barley by application of salicylic acid and potassium nitrate. J Saudi Soc Agric Sci. 2014; 13: 45-55.

36. Siddiqui MH, Alamri SA, Al-Khaishany YY, Al-Qutami MA, Ali HM. Ascorbic acid application improves salinity stress tolerance in wheat. Chiang Mai J Sci. 2018; 45: 1-11.

37. Önem B, Doğru A, Ongun Sevindik T, Tunca H. Preliminary study on the effects of heavy metals on the growth and some antioxidant enzymes in Arthrospira platensis-M2 strain. Phycol Res. 2018; 66: 23-30.

38. Azevedo RA, Carvalho RF, Cia MC, Gratao PL. Sugarcane under pressure: an overview of biochemical and physiological studies of abiotic stress. Trop Plant Biol. 2011; 4: 42-51.

39. Zheng Y, Jia A, Ning T, Xu J, Li Z, Jaing G. Potassium nitrate application alleviates sodium chloride stress in winter wheat cultivars differing in salt tolerance. J Plant Physiol. 2008; 165: 1455-1465.

40. Soleimanzadeh HD, Habibi MR, Ardakani F, Peknejad Rejali F. Effect of potassium levels on antioxidant enzymes and malondialdehyde content under drought stress in sunflower (Helianthus annuus L.). Am J Agric Biol Sci. 2010; 5: 56-61.

41. Abbasi GH, Akhtar J, Haq MA, Ali S, Chen ZH, Malik W. Exogenous potassium differentially mitigated salt stress in tolerant and sensitive maize hybrids. Pak J Bot. 2014; 46: 135-146.

42. Abbasi GH, Akhtar J, Ahmad R, Jamil M, Anwar-ul-Haq M, Ali S, Ijaz M. Potassium application mitigates salt stress differentially at different growth stages in tolerant and sensitive maize hybrids. Plant Growth Regul. 2015; 76: 111-125.

43. Ali G, Srivastava PS, Iqbal M. Proline accumulation, protein pattern and photosynthesis in regenerants grown under NaCl stress. Biol Plant. 1999; 42: 89-95.

44. Ashraf M, Foolad M. Roles of glycinebetaine and proline in improving plant abiotic stress tolerance. Env Exp Bot. 2007; 59: 206-216.

45. Shekari F, Abbasi A, Mustafavi SH. Effect of silicon and selenium on enzymatic changes and productivity of dill in saline condition. J Saudi Soc Agric Sci. 2015; 16: 367-374.

46. Yaghubi K, Ghaderi N, Vafaee Y, Javadi T. Potassium silicate alleviates deleterious effect of salinity on two strawberry cultivars grown under soilless pot culture. Sci Hort. 2016; 213: 87-95.
How to Cite
Doğru, A.; Demirtaş, E. Exogenous Potassium Nitrate Alleviates Salt-Induced Oxidative Stress in Maize. European Journal of Biological Research 2020, 11, 24-33.
Research Articles