Roquyya Ghulam, Shoaib Amna, Parveen Shagufta, Rafiq Muhammad
Department of Plant Pathology, Faculty of Agricultural Sciences, University of the Punjab, Lahore, Pakistan.
Jiangxi Key Laboratory for Sustainable Utilization of Chinese Materia Medica Resources, Lushan Botanical Garden, Chinese Academy of Science, Jiujiang, Jiangxi, 332900, China.
World J Microbiol Biotechnol. 2025 May 26;41(6):177. doi: 10.1007/s11274-025-04369-9.
The increasing resistance of fungal pathogens to synthetic fungicides necessitates eco-friendly alternatives. Zinc-chitosan (Zn-Ch) complexe offer a sustainable solution due to their biocompatibility and antifungal properties. This study synthesized and characterized Zn-Ch using UV-vis spectroscopy, Fourier transform infrared (FTIR) spectroscopy, dynamic light scattering (DLS), zeta potential, X-ray diffraction (XRD), and fluorescence spectral analysis, confirming strong Zn²⁺ interactions with chitosan. In vitro bioassays evaluated antifungal efficacy across different treatments: Mancozeb (chemical control), chitosan alone (Ch), non-complexed Zn (2.5 and 5.0 ppm) + Ch, and the Zn (5.0 ppm)-Ch complex. In all treatments, Mancozeb and Ch were tested at identical concentrations (0.5-2.5%) to ensure comparative analysis. Mancozeb and Ch exhibited dose-dependent inhibition, reaching 66.67% and 78.57% at 2.5%, respectively. Non-complexed Zn (2.5 and 5.0 ppm) + Ch demonstrated enhanced antifungal activity, with 5.0 ppm achieving 89.03% inhibition, while the Zn (5.0 ppm)-Ch complex exhibited the highest antifungal efficacy (99% inhibition) with severe hyphal distortion and delayed sporulation. Biochemical assays revealed an initial increase in catalase (CAT), peroxidase (POX), polyphenol oxidase (PPO), and phenylalanine ammonia-lyase (PAL) activities, peaking at 1.0-1.5%, followed by significant declines at higher concentrations. The Zn (5.0 ppm)-Ch complex caused the steepest enzymatic decline at 2.0-2.5%, suggesting oxidative stress-induced fungal suppression. Collectively, these findings confirmed the potential of the Zn-Ch complex in enhancing antifungal efficacy by altering fungal morphology, suppressing growth, and activating enzymatic defense responses in plants. Zn-Ch emerged as a promising, biocompatible alternative to synthetic fungicides, warranting further in vivo validation for its application in sustainable crop protection strategies.
真菌病原体对合成杀菌剂的耐药性不断增强，因此需要环保的替代方案。锌-壳聚糖（Zn-Ch）复合物因其生物相容性和抗真菌特性提供了一种可持续的解决方案。本研究使用紫外可见光谱、傅里叶变换红外（FTIR）光谱、动态光散射（DLS）、zeta电位、X射线衍射（XRD）和荧光光谱分析对Zn-Ch进行了合成和表征，证实了Zn²⁺与壳聚糖之间有强烈的相互作用。体外生物测定评估了不同处理的抗真菌效果：代森锰锌（化学对照）、单独的壳聚糖（Ch）、未复合的锌（2.5和5.0 ppm）+Ch以及锌（5.0 ppm）-壳聚糖复合物。在所有处理中，代森锰锌和壳聚糖均以相同浓度（0.5-2.5%）进行测试，以确保进行比较分析。代森锰锌和壳聚糖表现出剂量依赖性抑制，在2.5%时分别达到66.67%和78.57%。未复合的锌（2.5和5.0 ppm）+Ch表现出增强的抗真菌活性，5.0 ppm时抑制率达到89.03%，而锌（5.0 ppm）-壳聚糖复合物表现出最高的抗真菌效果（99%抑制率），伴有严重的菌丝变形和孢子形成延迟。生化分析显示，过氧化氢酶（CAT）、过氧化物酶（POX）、多酚氧化酶（PPO）和苯丙氨酸解氨酶（PAL）的活性最初有所增加，在1.0-1.5%时达到峰值，随后在较高浓度下显著下降。锌（5.0 ppm）-壳聚糖复合物在2.0-2.5%时导致酶活性下降最为剧烈，表明氧化应激诱导了真菌抑制。总体而言，这些发现证实了Zn-Ch复合物通过改变真菌形态、抑制生长和激活植物中的酶防御反应来增强抗真菌效果的潜力。Zn-Ch成为合成杀菌剂一种有前景的生物相容性替代品，其在可持续作物保护策略中的应用有待进一步进行体内验证。
