Bigham Soostani Sarvenaz, Ranjbar Monireh, Memarian Amir, Afshari Mozhdeh
Faculty of Marine Science and Technology, Hormozgan University, Bandar Abbas, Iran.
Department of Biology, Fal.C, Islamic Azad University, Isfahan, Iran.
Sci Rep. 2025 Aug 2;15(1):28219. doi: 10.1038/s41598-025-13996-z.
Salt stress affects plant growth and development to a great extent in establishing biochemical imbalances and inducing oxidative damage. The effort was undertaken to assess the relative effectiveness of chitosan pre- and post-treatments in relieving salt stress in Brassica napus L., a moderately salt-sensitive oilseed crop, with respect to the expression patterns of P5CS, PIP, and APX genes along with proline and protein accumulation. One factorial experiment was performed under controlled conditions, where the plants were exposed to varying NaCl concentrations (50, 100, 150, and 200 mM), following either the pre-treatment of chitosan (50 mg/L) or post-treatment of chitosan (50 and 100 mg/L). Gene expression analysis by means of qRT-PCR showed a significant (p < 0.05) upregulation under pre-treatment of P5CS and APX, thereby enhancing osmoprotection and antioxidant defense; however, under post-treatment, the response of P5CS and APX was only moderate. Post-treatment levels of proline and total protein were markedly higher as well. Interestingly, proline content increased by approximately 743% in pre-treated plants at 200 mM of NaCl compared to the control (p < 0.05), indicating enhanced stress tolerance. Besides, the plants subjected to pre-treatment were perfectly grown at 200 mM NaCl whereas those subjected to post-treatment were unable to survive at 150 mM. These findings reveal that the salt tolerance mechanism is better gained by chitosan pre-treatment due to osmotic adjustment enhancement and antioxidative mechanism. This study presents the potential of chitosan to be developed as a strategic biostimulant in promoting crop resistance to saline conditions.
盐胁迫在建立生化失衡和诱导氧化损伤方面对植物生长发育有很大影响。本研究旨在评估壳聚糖预处理和后处理在缓解甘蓝型油菜（一种中度盐敏感的油料作物）盐胁迫方面的相对有效性，涉及P5CS、PIP和APX基因的表达模式以及脯氨酸和蛋白质的积累。在可控条件下进行了单因素实验，将植物暴露于不同的NaCl浓度（50、100、150和200 mM）下，分别进行壳聚糖预处理（50 mg/L）或壳聚糖后处理（50和100 mg/L）。通过qRT-PCR进行的基因表达分析表明，在P5CS和APX预处理下有显著（p < 0.05）上调，从而增强了渗透保护和抗氧化防御；然而，在后处理下，P5CS和APX的反应仅为中等程度。后处理的脯氨酸和总蛋白水平也明显更高。有趣的是，与对照相比，在200 mM NaCl预处理的植物中脯氨酸含量增加了约743%（p < 0.05），表明胁迫耐受性增强。此外，预处理的植物在200 mM NaCl下生长良好，而后处理的植物在150 mM时无法存活。这些发现表明，由于渗透调节增强和抗氧化机制，壳聚糖预处理能更好地获得耐盐机制。本研究展示了壳聚糖作为一种战略生物刺激剂在促进作物抗盐性方面的潜力。
