Ahmed Temoor, Shou Linfei, Guo Junning, Noman Muhammad, Qi Yetong, Yao Yanlai, Masood Hafiza Ayesha, Rizwan Muhammad, Ali Md Arshad, Ali Hayssam M, Li Bin, Qi Xingjiang
Xianghu Laboratory, Hangzhou 311231, China; State Key Laboratory of Rice Biology and Breeding, Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China.
Station for the Plant Protection & Quarantine and Control of Agrochemicals Zhejiang Province, Hangzhou 310004, China.
Sci Total Environ. 2024 Jul 10;933:173068. doi: 10.1016/j.scitotenv.2024.173068. Epub 2024 May 8.
Cadmium (Cd) is an extremely toxic heavy metal that can originate from industrial activities and accumulate in agricultural soils. This study investigates the potential of biologically synthesized silicon oxide nanoparticles (Bio-SiNPs) in alleviating Cd toxicity in bayberry plants. Bio-SiNPs were synthesized using the bacterial strain Chryseobacterium sp. RTN3 and thoroughly characterized using advanced techniques. A pot experiment results demonstrated that Cd stress substantially reduced leaves biomass, photosynthesis efficiency, antioxidant enzyme activity, and induced oxidative damage in bayberry (Myrica rubra) plants. However, Bio-SiNPs application at 200 mg kg significantly enhanced plant biomass, chlorophyll content (26.4 %), net photosynthetic rate (8.6 %), antioxidant enzyme levels, and mitigated reactive oxygen species production under Cd stress. Bio-SiNPs modulated key stress-related phytohormones by increasing salicylic acid (13.2 %) and abscisic acid (13.7 %) contents in plants. Bio-SiNPs augmented Si deposition on root surfaces, preserving normal ultrastructure in leaf cells. Additionally, 16S rRNA gene sequencing demonstrated that Bio-SiNPs treatment favorably reshaped structure and abundance of specific bacterial groups (Proteobacteria, Actinobacteriota, and Acidobacteriota) in the rhizosphere. Notably, Bio-SiNPs application significantly modulated the key metabolites (phenylacetaldehyde, glycitein, maslinic acid and methylmalonic acid) under both normal and Cd stress conditions. Overall, this study highlights that bio-nanoremediation using Bio-SiNPs enhances tolerance to Cd stress in bayberry plants by beneficially modulating biochemical, microbial, and metabolic attributes.
镉（Cd）是一种剧毒重金属，可源自工业活动并在农业土壤中积累。本研究调查了生物合成的氧化硅纳米颗粒（Bio-SiNPs）缓解杨梅植株镉毒性的潜力。使用菌株金黄杆菌属RTN3合成了Bio-SiNPs，并采用先进技术对其进行了全面表征。盆栽试验结果表明，镉胁迫显著降低了杨梅植株的叶片生物量、光合作用效率、抗氧化酶活性，并诱导了氧化损伤。然而，在200 mg/kg的剂量下施用Bio-SiNPs显著提高了植株生物量、叶绿素含量（26.4%）、净光合速率（8.6%）、抗氧化酶水平，并减轻了镉胁迫下活性氧的产生。Bio-SiNPs通过增加植物中水杨酸（13.2%）和脱落酸（13.7%）的含量来调节与胁迫相关的关键植物激素。Bio-SiNPs增加了根表面的硅沉积，保持了叶细胞的正常超微结构。此外，16S rRNA基因测序表明，Bio-SiNPs处理有利于重塑根际特定细菌类群（变形菌门、放线菌门和酸杆菌门）的结构和丰度。值得注意的是，在正常和镉胁迫条件下，Bio-SiNPs的施用均显著调节了关键代谢物（苯乙醛、黄豆黄素、山楂酸和甲基丙二酸）。总体而言，本研究强调，使用Bio-SiNPs进行生物纳米修复可通过有益地调节生化、微生物和代谢特性来增强杨梅植株对镉胁迫的耐受性。
