A plant-based biostimulant approach to improve salt stress tolerance in tomato: The role of Hypericum heterophyllum Vent. extract

Öz

Salt stress severely limits seed germination and early seedling establishment in tomato. Plant-derived extracts have recently attracted attention as eco-friendly biostimulants capable of enhancing stress tolerance. The present study investigated the effects of different concentrations of Hypericum heterophyllum whole-plant extract on seed germination, seedling growth, and changes in physiological and biochemical parameters in tomato under salt stress. Tomato seeds were primed with aqueous H. heterophyllum extract at 0.25, 0.5, 1, and 2% (w/v) and subsequently exposed to NaCl-induced (200 mM) salinity stress. Germination percentage, mean germination time, root and shoot length (at early and late seedling stages), membrane damage, total chlorophyll content, and total flavonoid and phenolic contents in tomato leaves were evaluated. Salt stress markedly reduced germination and seedling growth, whereas H. heterophyllum extract treatments significantly alleviated these inhibitory effects in a concentration-dependent manner. The 0.5% and 1% extract concentrations were the most effective in improving germination performance and seedling growth under salt stress. These treatments also decreased membrane damage and increased total chlorophyll content. Moreover, increasing extract concentration led to higher total phenolic and flavonoid contents under salt stress. Overall, these findings suggest that H. heterophyllum extract has strong potential as a natural biostimulant and could be considered a promising, sustainable strategy to enhance salt stress tolerance and improve crop establishment in agricultural production.

Anahtar Kelimeler

• Hypericum heterophyllum
• Salt stress
• Tomato
• Seed priming
• Biostimulant.

Domateste tuz stresi toleransını artırmak için bitki bazlı bir biyostimülan yaklaşımı: Hypericum heterophyllum Vent. özütünün rolü

Öz

Tuz stresi, domateste tohum çimlenmesini ve erken fide oluşumunu ciddi şekilde sınırlandırmaktadır. Bitki kaynaklı özler, son zamanlarda stres toleransını artırabilen çevre dostu biyostimülanlar olarak dikkat çekmektedir. Bu çalışma, Hypericum heterophyllum bitkisinin tamamının farklı konsantrasyonlarının, tuz stresi koşulları altında domateste tohum çimlenmesi, fide büyümesi ve bazı fizyolojik ve biyokimyasal parametrelerdeki değişiklikler üzerindeki etkilerini araştırmıştır. Domates tohumları, %0,25, %0,5, %1 ve %2 (w/v) oranlarında sulu H. heterophyllum özü ile ön işleme tabi tutulmuş ve daha sonra NaCl kaynaklı (200 mM) tuz stresine maruz bırakılmıştır. Çimlenme yüzdesi, ortalama çimlenme süresi, kök ve sürgün uzunluğu (erken ve geç fide aşamalarında), membran hasarı, toplam klorofil içeriği ve domates yapraklarındaki toplam flavonoid ve fenolik içerik değerlendirilmiştir. Tuz stresi, çimlenmeyi ve fide büyümesini belirgin şekilde azaltırken, H. heterophyllum özü uygulamaları, bu engelleyici etkileri konsantrasyona bağlı olarak önemli ölçüde hafifletmiştir. %0,5 ve %1'lik ekstrakt konsantrasyonları, tuz stresi altında çimlenme performansını ve fide büyümesini iyileştirmede en etkili olanlardı. Bu uygulamalar ayrıca membran hasarını azalttı ve toplam klorofil içeriğini artırdı. Dahası, ekstrakt konsantrasyonunun artması, tuz stresi altında daha yüksek toplam fenolik ve flavonoid içeriğine yol açtı. Genel olarak, bu bulgular H. heterophyllum ekstraktının doğal bir biyostimülan olarak güçlü bir potansiyele sahip olduğunu ve tarımsal üretimde tuz stresi toleransını artırmak ve mahsul gelişimini iyileştirmek için umut vadeden, sürdürülebilir bir strateji olarak değerlendirilebileceğini göstermektedir.

Anahtar Kelimeler

• Hypericum heterophyllum
• Tuz stresi
• Domates
• Tohum ön işlem
• Biyostimülan.

Kaynakça

1. Akram N, Saleem M, Shafiq S, Naz H, Farid-Ul-Haq M, Ali B, Shafiq F, Iqbal M, Jaremko M, Qureshi K (2022). Phytoextracts as crop biostimulants and natural protective agents-A critical review. Sustainability 14: 14498. https://doi.org/10.3390/su142114498
2. Alkharabsheh H, Seleiman M, Hewedy O, Battaglia M, Jalal R, Alhammad B, Schillaci C, Ali N, Al-Doss A (2021). Field crop responses and management strategies to mitigate soil salinity in modern agriculture: A review. Agronomy 11: 2299. https://doi.org/10.3390/agronomy11112299
3. Almutairi Z, Arabia S (2016). Effect of nano-silicon application on the expression of salt tolerance genes in germinating tomato (Solanum lycopersicum L.) seedlings under salt stress. Plant Omics 9: 106.
4. Arnon DI (1949). Copper enzymes in isolated chloroplasts. Polyphenoloxidase in Beta vulgaris. Plant Physiology 24(1): 1-15.
5. Asif A, Ali M, Qadir M, Karthikeyan R, Singh Z, Khangura R, Di Gioia F, Ahmed Z (2023). Enhancing crop resilience by harnessing the synergistic effects of biostimulants against abiotic stress. Frontiers in Plant Science 14: 1276117. https://doi.org/10.3389/fpls.2023.1276117
6. Balasubramaniam T, Shen G, Esmaeili N, Zhang H (2023). Plants’ response mechanisms to salinity stress. Plants 12: 2253. https://doi.org/10.3390/plants12122253
7. Berrío H, Cardenal-Rubio Z (2025). Hormones mitigate salt stress in tomato (Solanum lycopersicum L.) plants during vegetative growth. Agronomía Colombiana 43(1): 118425.
8. Bogoutdinova L, Khaliluev M, Chaban I, Gulevich A, Shelepova O, Baranova E (2024). Salt tolerance assessment of different tomato varieties at the seedling stage. Horticulturae 10: 598.

9. Borromeo I, Domenici F, Del Gallo M, Forni C (2023). Role of polyamines in the response to salt stress of tomato. Plants 12: 1855. https://doi.org/10.3390/plants12091855
10. Bruňáková K, Bálintová M, Petijová L, Čellárová E (2022). Does phenotyping of Hypericum secondary metabolism reveal a tolerance to biotic/abiotic stressors? Frontiers in Plant Science 13: 1042375.
11. Caliskan O, Radušienė J, Temizel K, Staunis Z, Cirak C, Kurt D, Odabaş M (2017). The effects of salt and drought stress on phenolic accumulation in greenhouse-grown Hypericum pruinatum. Italian Journal of Agronomy 12: 918. https://doi.org/10.4081/ija.2017.918
12. Eray N, Dalar A, Türker M (2020). The effects of abiotic stressors and signal molecules on phenolic composition and antioxidant activities of in vitro regenerated Hypericum perforatum (St. John’s wort). South African Journal of Botany 133: 253-263. https://doi.org/10.1016/j.sajb.2020.07.03
13. Erenler R, Yaman C, Demirtas L, Alma H (2023). Phytochemical investigation of Hypericum heterophyllum flowers: LC-ESI-MS/MS analysis, total phenolic and flavonoid contents, antioxidant activity. The Natural Products Journal 13: 1366-1375.
14. Findura P, Hara P, Szparaga A, Kocira S, Czerwińska E, Bartos P, Nowak J, Treder K (2020). Evaluation of the effects of allelopathic aqueous plant extracts, as potential preparations for seed dressing, on the modulation of cauliflower seed germination. Agriculture 10: 122.
15. Flowers TJ, Colmer TD (2008). Salinity tolerance in halophytes. New phytologist 179(4): 945-963.
16. Ge L, Yang X, Liu Y, Tang H, Wang Q, Chu S, Hu J, Zhang N, Shi Q (2023). Improvement of seed germination under salt stress via overexpressing caffeic acid O-methyltransferase 1 (SlCOMT1) in Solanum lycopersicum L. International Journal of Molecular Sciences 24: 734.
17. Guo M, Wang X, Guo H, Bai S, Khan A, Wang X, Gao Y, Li J (2022). Tomato salt tolerance mechanisms and their potential applications for fighting salinity: A review. Frontiers in Plant Science 13: 949541.
18. Habibi N, Terada N, Sanada A, Koshio K (2024). Alleviating salt stress in tomatoes through seed priming with polyethylene glycol and sodium chloride combination. Stresses 4(2): 210-224.
19. Heath RL, Packer L (1968). Photoperoxidation in isolated chloroplasts: I. Kinetics and stoichiometry of fatty acid peroxidation. Archives of Biochemistry and Biophysics 125(1): 189-198.
20. Kim SJ, Son KH, Chang HW, Kang SS, Kim HP (2003). Tyrosinase inhibitory prenylated flavonoids from Sophora flavescens. Biological and Pharmaceutical Bulletin 26: 1348-1350.
21. Luong T, Lương T (2025). Potential use of spent tea leaves extract (Camellia sinensis L.) to promote early growth of salt-stressed seedlings of black cherry tomatoes (Solanum lycopersicum L. var. cerasiforme). Tạp chí Khoahọc 22(3): 4616. 10.54607/hcmue.js.22.3.4616(2025)
22. Mauromicale G, Licandro P (2002). Salinity and temperature effects on germination, emergence and seedling growth of globe artichoke. Agronomie 22: 443-450.
23. Munns R, Tester M (2008). Mechanisms of salinity tolerance. Annual Review of Plant Biology 59: 651-681.
24. Nooh K, Salim A, Faizy W, Dargiri S, Meftahizade H (2025). Synergistic effects of plant growth regulators and Fe₃O₄ nanoparticles on in vitro organogenesis and bioactive compound production in Hypericum perforatum. BMC Plant Biology 25: 7409.
25. Ondrašek G, Rathod S, Manohara K, Gireesh C, Anantha M, Sakhare A, Parmar B, Yadav B, Bandumula N, Raihan F, Zielińska-Chmielewska A, Meriño-Gergichevich C, Reyes-Díaz M, Khan A, Panfilova O, Fuentealba A, Romero S, Nabil B, Wan C, Shepherd J, Horvatinec J (2022). Salt stress in plants and mitigation approaches. Plants 11: 717.
26. Oosten M, Pepe O, Pascale S, Silletti S, Maggio A (2017). The role of biostimulants and bioeffectors as alleviators of abiotic stress in crop plants. Chemical and Biological Technologies in Agriculture 4: 1-12.
27. Öcal A, Eroğlu H (2012). In vitro cytogenetic effects of Hypericum heterophyllum in human peripheral blood lymphocytes. Bangladesh Journal of Pharmacology 7: 36-41.
28. Papoui E, Koukounaras A (2025). Evaluation of Ascophyllum nodosum and Sargassum spp. seaweed extracts’ effect on germination of tomato under salinity stress. Horticulturae 11: 290.
29. Patil R, Dm C, B A, Achari R (2018). To find the efficacy of crude extract from plants on germination of seeds. International Journal of Phytomedicine 10: 2226.
30. Ranal MA, Santana DG (2006). How and why to measure the germination process? Brazilian Journal of Botany 29: 1-11.
31. Raza A, Tabassum J, Fakhar A, Sharif R, Chen H, Zhang C, Ju L, Fotopoulos V, Siddique K, Singh R, Zhuang W, Varshney R (2022). Smart reprograming of plants against salinity stress using modern biotechnological tools. Critical Reviews in Biotechnology 43: 1035-1062.
32. Roșca M, Mihalache G, Stoleru V (2023). Tomato responses to salinity stress: From morphological traits to genetic changes. Frontiers in Plant Science 14: 1118383.
33. Rys M, Saja-Garbarz D, Skoczowski A (2022). Phytotoxic effects of selected herbal extracts on the germination, growth and metabolism of mustard and oilseed rape. Agronomy 12: 110.
34. Shiade SRG, Zand-Silakhoor A, Fathi A, Rahimi R, Minkina T, Rajput V, Zulfiqar U, Chaudhary T (2024). Plant metabolites and signaling pathways in response to biotic and abiotic stresses: Exploring biostimulant applications. Plant Stress 10: 100454. https://doi.org/10.1016/j.stress.2024.100454
35. Shukla P, Mantin E, Adil M, Bajpai S, Critchley A, Prithiviraj B (2019). Ascophyllum nodosum-based biostimulants: Sustainable applications in agriculture for the stimulation of plant growth, stress tolerance, and disease management. Frontiers in Plant Science 10: 655.
36. Singleton VL, Orthofer R, Lamuela-Raventós RM (1999). Analysis of total phenols and other oxidation substrates and antioxidants by means of folin-ciocalteu reagent. Methods in Enzymology 299: 152-178.
37. Su H, Li J, Chen S, Sun P, Xing H, Yang D, Zhang X, Li M, Wei J (2021). Physiological and transcriptomic analysis provide insight into low temperature enhancing hypericin biosynthesis in Hypericum perforatum. Molecules 26: 2294. https://doi.org/10.3390/molecules26082294
38. Torun H, Eroğlu E, Yalcin V, Usta E (2020). Physicochemical and antioxidant responses of St. John’s wort (Hypericum perforatum L.) under drought stress. Düzce University Journal of Science and Technology 9: 40-50. https://doi.org/10.29130/dubited.847860
39. Xu Z, Pehlivan N, Ghorbani A, Wu C (2022). Effects of Azorhizobium caulinodans and Piriformospora indica co-inoculation on growth and fruit quality of tomato (Solanum lycopersicum L.) under salt stress. Horticulturae 8: 302.
40. Yaman C (2020). Phytochemicals and antioxidant capacity of wild growing and in vitro Hypericum heterophyllum. Romanian Biotechnological Letters 25: 2111-2117.
41. Yaman C, Şimşek Ş (2022). Contact toxicity of Hypericum extracts against Rhyzopertha dominica (Fab.) (Coleoptera: Bostrichidae). Tekirdağ Ziraat Fakültesi Dergisi 19: 695-704.
42. Ying Y, Freitas H, Dias M (2022). Strategies and prospects for biostimulants to alleviate abiotic stress in plants. Frontiers in Plant Science 13: 1024243.
43. Zhao S, Zhang Q, Liu M, Zhou H, Wang P (2021). Regulation of plant responses to salt stress. International Journal of Molecular Sciences 22: 4609.