Bigham Soostani Sarvenaz, Ranjbar Monireh, Memarian Amir, Mohammadi Mehrnoosh, Yaghini Zahra
Faculty of Marine Science and Technology, Hormozgan University, Bandar Abbas, Iran.
Department of Biology, Fal.C, Islamic Azad University, Isfahan, Iran.
BMC Plant Biol. 2025 Jul 2;25(1):824. doi: 10.1186/s12870-025-06815-0.
Salt stress significantly impairs plant growth and productivity. This study evaluated the effects of foliar-applied chitosan on salt stress mitigation in Brassica napus L. under NaCl treatments (0, 50, 100, 150 mM). Plants were treated with chitosan (0, 5, and 10 mg/L), and their physiological, biochemical, and molecular responses were analyzed. Chitosan at 10 mg/L significantly improved biomass production, root development, and photosynthetic efficiency, increasing total chlorophyll content by up to 35% under severe salinity (150 mM NaCl). It enhanced ion homeostasis by reducing sodium (Na) accumulation (up to 19%) and increasing potassium (K) uptake (up to 27%), mitigating ion toxicity. Chitosan at 10 mg/L also improved membrane stability and osmotic adjustment by elevating phenolics (47%), flavonoids (40%), and anthocyanins (60%), particularly under 100 and 150 mM NaCl. Antioxidant defense mechanisms were strengthened, with 10 mg/L chitosan increasing superoxide dismutase (SOD) activity by 15%, ascorbate peroxidase (APX) by 35%, and catalase (CAT) by 168%, leading to a 30% reduction in hydrogen peroxide (HO) content, primarily under high salinity (100-150 mM NaCl). Additionally, chitosan upregulated the expression of stress-related genes, including SOD (55%), APX (26%), and phenylalanine ammonia-lyase (PAL) (45%), reinforcing the oxidative defense system. These findings highlight chitosan's role in salt tolerance via ion regulation, osmolyte synthesis, and antioxidant modulation, with 10 mg/L being the most effective concentration. Chitosan represents a promising biostimulant for enhancing crop resilience in saline environments. Future research should optimize formulations for large-scale applications and assess long-term effects on soil and plant health.
盐胁迫显著损害植物生长和生产力。本研究评估了叶面喷施壳聚糖对甘蓝型油菜在NaCl处理（0、50、100、150 mM）下缓解盐胁迫的影响。用壳聚糖（0、5和10 mg/L）处理植株，并分析其生理、生化和分子反应。10 mg/L的壳聚糖显著提高了生物量产量、根系发育和光合效率，在严重盐度（150 mM NaCl）下总叶绿素含量增加了35%。它通过减少钠（Na）积累（高达19%）和增加钾（K）吸收（高达27%）来增强离子稳态，减轻离子毒性。10 mg/L的壳聚糖还通过提高酚类物质（47%）、黄酮类化合物（40%）和花青素（60%）来改善膜稳定性和渗透调节，特别是在100和150 mM NaCl条件下。抗氧化防御机制得到加强，10 mg/L的壳聚糖使超氧化物歧化酶（SOD）活性增加15%，抗坏血酸过氧化物酶（APX）增加35%，过氧化氢酶（CAT）增加168%，导致过氧化氢（HO）含量降低30%，主要是在高盐度（100 - 150 mM NaCl）条件下。此外，壳聚糖上调了与胁迫相关基因的表达，包括SOD（55%）、APX（26%）和苯丙氨酸解氨酶（PAL）（45%），加强了氧化防御系统。这些发现突出了壳聚糖通过离子调节、渗透调节剂合成和抗氧化调节在耐盐性中的作用，10 mg/L是最有效的浓度。壳聚糖是一种有前途的生物刺激剂，可增强作物在盐渍环境中的恢复力。未来的研究应优化大规模应用的配方，并评估对土壤和植物健康的长期影响。
