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Rhodophyte-derived biostimulants: Galaxaura oblongata (J Ellis & Solander) J V Lamouroux, extract mitigates salinity stress in maize by integrating ionic homeostasis and antioxidant networking

DOI
https://doi.org/10.14719/pst.13885
Submitted
28 January 2026
Published
02-07-2026
Versions

Abstract

Soil salinity is a challenging bottleneck to global agricultural sustainability, affecting over 10.7 % of irrigated lands. While phyto-derived biostimulants have emerged as promising mitigants and offer sustainable path for mitigating osmotic and ionic stress under saline conditions, the potential of red macroalgae remains largely underexplored. This study used a pot experiment to evaluate the potential and efficacy of rhodophyte, Galaxaura oblongata extract (GOE), applied through seed priming and foliar spray, in enhancing the morpho-physio-biochemical resilience of Zea mays L. under 150 mM sodium chloride (NaCl) stress. Comprehensive phytochemical profiling of GOE revealed an abundance of essential nutrients (potassium (K), nitrogen (N), calcium (Ca), magnesium (Mg), sulfur (S) and phosphorus (P)), amino acids (leucine, valine and lysine), osmoprotectants (proline and glycine betaine) and polyphenolic antioxidants (phenolics and flavonoids). The GOE application significantly alleviated salinity-induced growth inhibition by increasing shoot height by up to 18.05 %, leaf area and relative water content by up to 140.70 %. Furthermore, GOE treatment enhanced photosynthetic pigment synthesis and stabilised photosystem II (PSII) efficiency (maximum quantum efficiency of photosystem II photochemistry (Fv/Fm)). Oxidative damage indicators, i.e. H₂O₂, OH•, electrolyte leakage and malondialdehyde (MDA), were markedly reduced through the upregulation and modulation of enzymatic (peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX) and polyphenol oxidase (PPO)) and non-enzymatic (phenolics, flavonoids and glycine betaine) antioxidant defence systems. Crucially, GOE restored mineral homeostasis through improved osmotic regulation by moderating excessive proline and soluble sugar accumulation, by suppressing Na+ accumulation by 40.38 % and preserving a favourable K+/Na+ ratio of 2.39. Collectively, these findings establish GOE as an effective, potent and multifunctional rhodophyte-based biostimulant, capable of mitigating salinity stress and enhancing maize productivity in saline environments through integrated physiological and biochemical mechanisms. The study also provides a scalable framework for sustainable agriculture and improved crop productivity.

References

  1. 1. Demo AH, Gemeda MK, Abdo DR, Guluma TN, Adugna DB. Impact of soil salinity, sodicity and irrigation water salinity on crop production and coping mechanism in areas of dryland farming. Agrosyst Geosci Environ. 2025;8(1):e70072. https://doi.org/10.1002/agg2.70072
  2. 2. Khan R, Liu J. Coordinate to combat Pakistan’s climate-driven disasters. Nature. 2025;645:e592. https://doi.org/10.1038/d41586-025-03004-9
  3. 3. Ungaro F, Calzolari C, Fantappiè M, Napoli R, Barbetti R, Tarocco P, et al. National mapping and reporting of salt-affected soils of Italy. Rome (IT); 2024.
  4. 4. Isayenkov SV, Maathuis FJMM. Plant salinity stress: Many unanswered questions remain. Front Plant Sci. 2019;10:80. https://doi.org/10.3389/fpls.2019.00080
  5. 5. Eswar D, Karuppusamy R, Chellamuthu S. Drivers of soil salinity and their correlation with climate change. Curr Opin Environ Sustain. 2021;50:310–8. https://doi.org/10.1016/j.cosust.2020.10.015
  6. 6. Cao Y, Zhou X, Song H, Zhang M, Jiang C. Advances in deciphering salt tolerance mechanism in maize. Crop J. 2023;11(4):1001–10. https://doi.org/10.1016/j.cj.2022.12.004
  7. 7. van Zelm E, Zhang Y, Testerink C. Salt tolerance mechanisms of plants. Annu Rev Plant Biol. 2020;71:403–33. https://doi.org/10.1146/annurev-arplant-050718-100005
  8. 8. Munns R, Tester M. Mechanisms of salinity tolerance. Annu Rev Plant Biol. 2008;59:651–81. https://doi.org/10.1146/annurev.arplant.59.032607.092911
  9. 9. Singh R, Singh Y, Xalaxo S, Verulkar S, Yadav N, Singh S, et al. From QTL to variety-harnessing the benefits of QTLs for drought, flood and salt tolerance in mega rice varieties of India through a multi-institutional network. Plant Sci. 2016;242:278–87. https://doi.org/10.1016/j.plantsci.2015.08.008
  10. 10. Pienaar BC, Majeke BM, Wittenberg MF, Adetunji AE, Nephali L, Tugizimana F, et al. Mitigating salt stress in maize using Ecklonia maxima seaweed extracts. Plant Stress. 2025;16:100828. https://doi.org/10.1016/j.stress.2025.100828
  11. 11. Deolu-Ajayi AO, van der Meer IM, van der Werf A, Karlova R. The power of seaweeds as plant biostimulants to boost crop production under abiotic stress. Plant Cell Environ. 2022;45(9):2537–53. https://doi.org/10.1111/pce.14391
  12. 12. Drira M, Ben Mohamed J, Ben Hlima H, Hentati F, Michaud P, Abdelkafi S, et al. Improvement of Arabidopsis thaliana salt tolerance using a polysaccharidic extract from the brown algae Padina pavonica. Algal Res. 2021;56:102324. https://doi.org/10.1016/j.algal.2021.102324
  13. 13. Hamouda MM, Badr A, Ali SS, Adham AM, Ahmed HIS, Saad-Allah KM. Growth, physiological and molecular responses of three phaeophyte extracts on salt-stressed pea (Pisum sativum L.) seedlings. J Genet Eng Biotechnol. 2023;21(1):32. https://doi.org/10.1186/s43141-023-00483-z
  14. 14. Aleem AA. The marine algae of Alexandria, Egypt. Alexandria; 1993. p. 138.
  15. 15. Metzner H, Rau H, Senger H, Sieprawska A, Filek M, Tobiasz A, et al. Trace elements’ uptake and antioxidant response to excess of manganese in in vitro cells of sensitive and tolerant wheat. Planta. 1965;65(2):186–94. https://doi.org/10.1007/BF00384998
  16. 16. Velikova V, Yordanov I, Edreva A. Oxidative stress and some antioxidant systems in acid rain-treated bean plants. Plant Sci. 2000;151(1):59–66. https://doi.org/10.1016/S0168-9452(99)00197-1
  17. 17. Halliwell B, Aeschbacht R, Loligert J, Aruoma OI. The characterization of antioxidants. Food Chem Toxicol. 1995;33(7):601–17. https://doi.org/10.1016/0278-6915(95)00024-V
  18. 18. Heath RL, Packer L. Photoperoxidation in isolated chloroplasts: I. Kinetics and stoichiometry of fatty acid peroxidation. Arch Biochem Biophys. 1968;125(1):189–98. https://doi.org/10.1016/0003-9861(68)90654-1
  19. 19. Sairam RK, Srivastava GC, Agarwal S, Meena RC. Differences in antioxidant activity in response to salinity stress in tolerant and susceptible wheat genotypes. Biol Plant. 2005;49(1):85–91. https://doi.org/10.1007/s10535-005-5091-2
  20. 20. Kato M, Shimizu S. Chlorophyll metabolism in higher plants. VII. Chlorophyll degradation in senescing tobacco leaves; phenolic-dependent peroxidative degradation. Can J Bot. 1987;65(4):729–35. https://doi.org/10.1139/b87-097
  21. 21. Nakano Y, Asada K. Hydrogen peroxide is scavenged by ascorbate-specific peroxidase in spinach chloroplasts. Plant Cell Physiol. 1981;22(5):867–80. https://doi.org/10.1093/oxfordjournals.pcp.a076232
  22. 22. Kumar KB, Khan PA. Peroxidase and polyphenol oxidase in excised ragi (Eleusine corocana cv PR 202) leaves during senescence. Indian J Exp Biol. 1982;20(5):412–6.
  23. 23. Jindal KK, Singh RN. Phenolic content in male and female Carica papaya: A possible physiological marker for sex identification of vegetative seedlings. Physiol Plant. 1975;33(1):104–7. https://doi.org/10.1111/j.1399-3054.1975.tb03774.x
  24. 24. Chang CC, Yang MH, Wen HM, Chern JC. Estimation of total flavonoid content in propolis by two complementary colorimetric methods. J Food Drug Anal. 2002;10(3):178–82. https://doi.org/10.38212/2224-6614.2748
  25. 25. Oser BL. Hawk’s Physiological Chemistry. 14th ed. New York (NY): McGraw-Hill; 1979. p. 702–5.
  26. 26. Grieve CM, Grattan SR. Rapid assay for determination of water-soluble quaternary ammonium compounds. Plant Soil. 1983;70(2):303–7. https://doi.org/10.1007/BF02374789
  27. 27. Dubois M, Gilles K, Hamilton J, Rebers P, Smith F. Colorimetric method for determination of sugars and related substances. Anal Chem. 1965;28:350–6. https://doi.org/10.1021/ac60111a017
  28. 28. Bradford MM. A rapid and sensitive method for the quantitation of microgram quantities of protein utilising the principle of protein-dye binding. Anal Biochem. 1976;72(1–2):248–54. https://doi.org/10.1016/0003-2697(76)90527-3
  29. 29. Lee YP, Takahashi T. An improved colorimetric determination of amino acids with the use of ninhydrin. Anal Biochem. 1966;14(1):71–7. https://doi.org/10.1016/0003-2697(66)90057-1
  30. 30. Bates LS, Waldren RP, Teare ID. Rapid determination of free proline for water-stress studies. Plant Soil. 1973;39(1):205–7. https://doi.org/10.1007/BF00018060
  31. 31. Sermakkani M, Thangapandian V. Phytochemical screening for active compounds in Pedalium murex L. Recent Res Sci Technol. 2010;2(1):110–4.
  32. 32. Benzie IFF, Strain JJ. The ferric reducing ability of plasma (FRAP) as a measure of antioxidant power: The FRAP assay. Anal Biochem. 1996;239(1):70–6. https://doi.org/10.1006/abio.1996.0292
  33. 33. Allen SE, Grimshaw HM, Parkinson JA, Quarmby C. Chemical analysis of ecological materials. New York (NY): Blackwell Scientific Publications; 1974.
  34. 34. Steel RGD, Torrie JH. Principles and procedures of statistics: A biometrical approach. 2nd ed. Tokyo (JP): McGraw-Hill Kogakusha Ltd.; 1980.
  35. 35. Rajabi Hamedani S, Rouphael Y, Colla G, Colantoni A, Cardarelli M. Biostimulants as a tool for improving environmental sustainability of greenhouse vegetable crops. Sustainability. 2020;12:5101. https://doi.org/10.3390/su12125101
  36. 36. Abdelkader M, Voronina L, Baratova L, Shelepova O, Zargar M, Puchkov M, et al. Biostimulants-based amino acids augment physio-biochemical responses and promote salinity tolerance of lettuce plants (Lactuca sativa L.). Horticulturae. 2023;9(7):807. https://doi.org/10.3390/horticulturae9070807
  37. 37. Wang Y, Zeng FR, Wang Y, Xu S, Chen ZH. Potassium transporters and their evolution in plants under salt stress. In: Upadhyay SK, editor. Cation transporters in plants. Academic Press; 2022. p. 63–83. https://doi.org/10.1016/B978-0-12-819773-8.00019-8
  38. 38. Hawkesford MJ, Cakmak I, Coskun D, De Kok LJ, Lambers H, Schjoerring JK, et al. Functions of macronutrients. In: Rengel Z, Cakmak I, White PJ, editors. Marschner’s mineral nutrition of plants. 4th ed. San Diego (CA): Academic Press; 2023. p. 201–81. https://doi.org/10.1016/B978-0-12-819773-8.00019-8
  39. 39. Kumar D, Punetha A, Verma PPS, Padalia RC. Micronutrient based approach to increase yield and quality of essential oil in aromatic crops. J Appl Res Med Aromat Plants. 2022;26:100361. https://doi.org/10.1016/j.jarmap.2021.100361
  40. 40. Ashraf M, Foolad MR. Roles of glycine betaine and proline in improving plant abiotic stress resistance. Environ Exp Bot. 2007;59(2):206–16. https://doi.org/10.1016/j.envexpbot.2005.12.006
  41. 41. Saad-Allah KM, Elbana NM, Sobhy SE, Hafez EE, Khalifa AM, Huo S, et al. Static magnetic field-induced metabolic shifting: coordinated phenylpropanoid induction and antioxidant system regulation in Calotropis procera callus culture. BMC Plant Biol. 2026;26(1):376. https://doi.org/10.1186/s12870-025-07997-3
  42. 42. Chen THH, Murata N. Glycinebetaine protects plants against abiotic stress: Mechanisms and biotechnological applications. Plant Cell Environ. 2011;34(1):1–20. https://doi.org/10.1111/j.1365-3040.2010.02232.x
  43. 43. Noctor G, Foyer CH. Ascorbate and glutathione: Keeping active oxygen under control. Annu Rev Plant Biol. 1998;49(1):249–79. https://doi.org/10.1146/annurev.arplant.49.1.249
  44. 44. Zhao S, Zhang Q, Liu M, Zhou H, Ma C, Wang P. Regulation of plant responses to salt stress. Int J Mol Sci. 2021;22(9):4609. https://doi.org/10.3390/ijms22094609
  45. 45. Hasanuzzaman M, Bhuyan MHMB, Parvin K, Bhuiyan TF, Anee TI, Nahar K, et al. Regulation of ROS metabolism in plants under environmental stress: A review of recent experimental evidence. Int J Mol Sci. 2020;21(22):8695. https://doi.org/10.3390/ijms21228695
  46. 46. Zulfiqar F, Ashraf M. Nanoparticles potentially mediate salt stress tolerance in plants. Plant Physiol Biochem. 2021;160:257–68. https://doi.org/10.1016/j.plaphy.2021.01.028
  47. 47. EL Sabagh A, Islam MS, Skalicky M, Ali Raza M, Singh K, Anwar Hossain M, et al. Salinity stress in wheat (Triticum aestivum L.) in the changing climate: Adaptation and management strategies. Front Agron. 2021;3:661932. https://doi.org/10.3389/fagro.2021.661932
  48. 48. Gautam A, Chauhan A, Singh A, Mundepi S, Pant M, Husen A. Use of seaweed extract-based biostimulants in plant growth, biochemical constituents and productions. In: Husen A, editor. Plant biology, sustainability and climate change. Elsevier; 2024. p. 129–48. https://doi.org/10.1007/s13762-019-02442-z
  49. 49. Mukherjee A, Patel JS. Seaweed extract: biostimulator of plant defense and plant productivity. Int J Environ Sci Technol. 2020;17(1):553–8. https://doi.org/10.1007/s13762-019-02442-z
  50. 50. Zhu M, Shabala S, Shabala L, Fan Y, Zhou MX. Evaluating predictive values of various physiological indices for salinity stress tolerance in wheat. J Agron Crop Sci. 2016;202(2):115–24. https://doi.org/10.1111/jac.12122
  51. 51. Nanda S, Kumar G, Hussain S. Utilization of seaweed-based biostimulants in improving plant and soil health: current updates and future prospective. Int J Environ Sci Technol. 2022;19(12):12839–52. https://doi.org/10.1007/s13762-021-03568-9
  52. 52. Mughunth RJ, Velmurugan S, Mohanalakshmi M, Vanitha K. A review of seaweed extract’s potential as a biostimulant to enhance growth and mitigate stress in horticulture crops. Sci Hortic. 2024;334:113312. https://doi.org/10.1016/j.scienta.2024.113312
  53. 53. Altaf MT, Nadeem MA, Ali A, Liaqat W, Bedir M, Baran N, et al. Applicability of Start Codon Targeted (SCoT) markers for the assessment of genetic diversity in bread wheat germplasm. Genet Resour Crop Evol. 2025;72(1):1205–18. https://doi.org/10.1007/s10722-024-02016-0
  54. 54. Baksi S, Singh KM, Rani S, Sharma P. Melatonin-functionalised zinc oxide nanoparticles enhance salt stress tolerance in Vigna mungo L. by regulating antioxidants and ion homeostasis. Environ Sci Nano. 2025;12(11):5056–73. https://doi.org/10.1039/D5EN00588D
  55. 55. Fang YJ, Yang XY, Xie LB, Zhang ZW, Yuan S. Enhancement of non-enzymatic antioxidants in Eutrema salsugineum under salt stress depends on salicylate depletion. Int J Mol Sci. 2026;27:1168. https://doi.org/10.3390/ijms27031168
  56. 56. Ma C, Wang P, Tao W, Zhou B, Wang Q, Deng M. Seaweed biostimulant supplementation improves maize resilience to saline-alkaline stress. Plant Stress. 2025;17:100933. https://doi.org/10.1016/j.stress.2025.100933
  57. 57. Alagoz SM, Lajayer BA, Ghorbanpour M. Proline and soluble carbohydrates biosynthesis and their roles in plants under abiotic stresses. In: Ghorbanpour M, Shahid MA, editors. Plant stress mitigators. San Diego (CA): Academic Press; 2023. p. 169–85. https://doi.org/10.1016/B978-0-323-89871-3.00027-6
  58. 58. Ahmad A, Akram NA, Ashraf M. Appraisal of the physio-biochemical efficacy of exogenously applied natural and synthetic sources of plant growth stimulants in modulating drought stress tolerance in maize (Zea mays L.). Acta Physiol Plant. 2025;47(3):28. https://doi.org/10.1007/s11738-024-03758-1
  59. 59. Yan L, Lu M, Riaz M, Tong K, Yu H, Gao G, et al. Exogenous proline enhances salt acclimation in soybean seedlings: Modifying physicochemical properties and controlling proline metabolism through the ornithine-glutamate dual pathway. Ecotoxicol Environ Saf. 2025;294:118012. https://doi.org/10.1016/j.ecoenv.2025.118012
  60. 60. Shukla PS, Shotton K, Norman E, Neily W, Critchley AT, Prithiviraj B. Seaweed extract improves drought tolerance of soybean by regulating stress-response genes. AoB Plants. 2018;10(1):plx051. https://doi.org/10.1093/aobpla/plx051
  61. 61. Rabhi ML, Derbak L, Bendif H, Boufahja F, Abu-Elsaoud AM, Garzoli S. Seaweed-derived biostimulants for sustainable crop production: A review. J Biotechnol. 2025;408:201–16. https://doi.org/10.1016/j.jbiotec.2025.09.013
  62. 62. Gandhi G, Gopalakrishnan VAK, Ghosh A. Response of maize to seed priming with seaweed extracts and plant growth promoting rhizobacteria. J Appl Phycol. 2024;36(5):2961–78. https://doi.org/10.1007/s10811-024-03306-x
  63. 63. Menaa F, Wijesinghe U, Thiripuranathar G, Althobaiti NA, Albalawi AE, Khan BA, et al. Marine algae-derived bioactive compounds: A new wave of nanodrugs? Mar Drugs. 2021;19(9):484. https://doi.org/10.3390/md19090484
  64. 64. Hussein MH, Eltanahy E, Al Bakry AF, Elsafty N, Elshamy MM. Seaweed extracts as prospective plant growth bio-stimulant and salinity stress alleviator for Vigna sinensis and Zea mays. J Appl Phycol. 2021;33(2):1273–91. https://doi.org/10.1007/s10811-020-02330-x
  65. 65. Islam MT, Arioli T, Cahill DM. Seaweed extract-stimulated priming in Arabidopsis thaliana and Solanum lycopersicum. Plants. 2021;10(11):2476. https://doi.org/10.3390/plants10112476
  66. 66. Dubey R, Misra S. Biostimulants: an eco-friendly regulator of plant stress tolerance and sustainable solution to future agriculture. Proc Indian Natl Sci Acad. 2024. https://doi.org/10.1007/s43538-024-00328-4
  67. 67. Zörb C, Geilfus CM, Dietz KJ. Salinity and crop yield. Plant Biol. 2019;21(S1):31–8. https://doi.org/10.1111/plb.12884
  68. 68. Kasim WA, Saad-Allah KM, Hamouda M. Seed priming with extracts of two seaweeds alleviates the physiological and molecular impacts of salinity stress on radish (Raphanus sativus). Int J Agric Biol. 2016;18(3):653–60. https://doi.org/10.17957/IJAB/15.0152
  69. 69. Biswas S, Seal P, Majumder B, Biswas AK. Efficacy of seed priming strategies for enhancing salinity tolerance in plants: An overview of the progress and achievements. Plant Stress. 2023;9:100186. https://doi.org/10.1016/j.stress.2023.100186
  70. 70. Alhawsa Z, Jalal R, Asiri N. Enhancing salt stress tolerance in Portulaca oleracea L. using Ascophyllum nodosum biostimulant. Phyton Int J Exp Bot. 2025;94(4):1319–37. https://doi.org/10.32604/phyton.2025.061918

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