Unveiling the Effect of Hydrolyzed Keratin on Arsenic Toxicity in Spinach and Associated Molecular Changes Revealed by Fourier Transform Infrared Spectroscopy


ŞAHİN Ö., İNAL E. K., GÜNEŞ A.

Journal of Soil Science and Plant Nutrition, cilt.25, sa.3, ss.8277-8286, 2025 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 25 Sayı: 3
  • Basım Tarihi: 2025
  • Doi Numarası: 10.1007/s42729-025-02672-w
  • Dergi Adı: Journal of Soil Science and Plant Nutrition
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, CAB Abstracts, Food Science & Technology Abstracts, Veterinary Science Database
  • Sayfa Sayıları: ss.8277-8286
  • Anahtar Kelimeler: FTIR, Heavy metal toxicity, Sustainable agriculture
  • Ankara Üniversitesi Adresli: Evet

Özet

Purpose: Arsenic (As) in soils threatens plant growth and food safety, requiring sustainable mitigation. This study examined the conversion of sheep wool (SW) to hydrolyzed keratin (HK) and its impact on spinach under As stress. Methods: The treatments were as follows: 1-Control, 2-As toxicity [As, 30 mg As kg− 1], 3-As + HK1 [30 mg As and 1.0 mL HK kg− 1 soil], 4-As + HK2 [30 mg As and 1.5 mL HK kg− 1 soil], 5-As + HK3 [30 mg As and 2.0 mL HK kg− 1 soil]. Results: Fourier transform infrared spectroscopy (FTIR) analysis revealed that while both SW and HK shared similarities due to their keratin content, hydrolysis introduced significant modifications. Peaks at 1527, 1643, and 2347 cm⁻¹ observed in SW were altered, with stronger peaks at 1373 and 1585 cm⁻¹ and new peaks at 2550 and 3250 cm⁻¹ appearing in HK, indicating increased solubility and functionalization. In As-contaminated soil, HK application especially at the highest dose significantly improved spinach biomass and reduced As accumulation from 0.75 to 0.22 mg kg⁻¹, while also enhancing plant N concentrations. FTIR analysis of spinach showed that As toxicity weakened peaks at 1028, 2920, and 3275 cm⁻¹ and eliminated those at 1236, 1317, and 1402 cm⁻¹, indicating disrupted cell wall structure or reduced carbohydrate synthesis. HK application partially restored these peaks and introduced a new one at 2328 cm⁻¹. Conclusion: Hydrolyzed keratin enhances plant growth and mitigates As toxicity, demonstrating its potential as a sustainable amendment for improving crop resilience in contaminated soils.