Abstract：
The consistently increasing use of zinc oxide nanoparticles (ZnONPs) in crop optimization practices and their persistence in agro-environment necessitate expounding their influence on sustainable agro-environment. Attempts have been made to understand nanoparticle-plant beneficial bacteria (PBB)- plant interactions; the knowledge of toxic impact of nanomaterials on soil-PBB-vegetable systems and alleviating nanotoxicity using PBB is scarce and inconsistent. This study aims at bio-fabrication of ZnONPs from Rosa indica petal extracts and investigates the impact of PBB on growth and biochemical responses of biofertilized eggplants exposed to phyto-synthesized nano-ZnO. Microscopic and spectroscopic techniques revealed nanostructure, triangular shape, size 32.5 nm, and different functional groups of ZnONPs and petal extracts. Inoculation of Pseudomonas fluorescens and Azotobacter chroococcum improved germination efficiency by 22% and 18% and vegetative growth of eggplants by 14% and 15% under NPs stress. Bio-inoculation enhanced total chlorophyll content by 36% and 14 %, increasing further with higher ZnONP concentrations. Superoxide dismutase and catalase activity in nano-ZnO and P. fluorescens inoculated eggplant shoots reduced by 15-23% and 9-11%. Moreover, in situ experiment unveiled distortion and accumulation of NPs in roots revealed by scanning electron microscope and confocal laser microscope. The present study highlights the phytotoxicity of biosynthesized ZnONPs to eggplants and demonstrates that PBB improved agronomic traits of eggplants while declining phytochemicals and antioxidant levels. These findings suggest that P. fluorescens and A. chroococcum, with NPs ameliorative activity, can be cost-effective and environment-friendly strategy for alleviating NPs toxicity and promoting eggplant production under abiotic stress, fulfilling vegetable demands.
摘要：
氧化锌纳米颗粒（ZnONPs）在作物优化实践中的持续使用及其在农业环境中的持久性，有必要阐述其对可持续农业环境的影响。已经尝试了解纳米颗粒-植物有益细菌（PBB）-植物相互作用；纳米材料对土壤-PBB-植物系统的毒性影响以及使用PBB减轻纳米毒性的知识很少且不一致。这项研究旨在生物制造的ZnONPs从玫瑰花瓣提取物和研究PBB对生长和生化反应的生物施肥茄子暴露于植物合成的纳米ZnO的影响。显微和光谱技术揭示了纳米结构，三角形,尺寸32.5nm，以及ZnONPs和花瓣提取物的不同官能团。在NPs胁迫下，接种荧光假单胞菌和嗜铜固氮菌的发芽效率分别提高了22％和18％，茄子的营养生长分别提高了14％和15％。生物接种使总叶绿素含量分别提高了36%和14%，随着更高的ZnONP浓度进一步增加。纳米ZnO和荧光假单胞菌接种茄子芽中的超氧化物歧化酶和过氧化氢酶活性降低了15-23％和9-11％。此外，原位实验揭示了扫描电子显微镜和共聚焦激光显微镜揭示的NPs在根中的变形和积累。本研究强调了生物合成的ZnONPs对茄子的植物毒性，并表明PBB改善了茄子的农艺性状，同时降低了植物化学物质和抗氧化剂水平。这些发现表明，荧光假单胞菌和嗜血杆菌，具有改善NPs的活性，可以是具有成本效益和环境友好的策略，以减轻NPs的毒性和促进茄子在非生物胁迫下的生产，满足蔬菜需求。
