Hu Peiguang, An Jing, Faulkner Maquela M, Wu Honghong, Li Zhaohu, Tian Xiaoli, Giraldo Juan Pablo
Department of Botany and Plant Sciences, University of California, Riverside, California 92521, United States.
State Key Laboratory of Plant Physiology and Biochemistry, College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China.
ACS Nano. 2020 Jul 28;14(7):7970-7986. doi: 10.1021/acsnano.9b09178. Epub 2020 Jul 13.
Fundamental and quantitative understanding of the interactions between nanoparticles and plant leaves is crucial for advancing the field of nanoenabled agriculture. Herein, we systematically investigated and modeled how ζ potential (-52.3 mV to +36.6 mV) and hydrodynamic size (1.7-18 nm) of hydrophilic nanoparticles influence delivery efficiency and pathways to specific leaf cells and organelles. We studied interactions of nanoparticles of agricultural interest including carbon dots (CDs, 0.5 and 5 mg/mL), cerium oxide (CeO, 0.5 mg/mL), and silica (SiO, 0.5 mg/mL) nanoparticles with leaves of two major crop species having contrasting leaf anatomies: cotton (dicotyledon) and maize (monocotyledon). Biocompatible CDs allowed real-time tracking of nanoparticle translocation and distribution by confocal fluorescence microscopy at high spatial (∼200 nm) and temporal (2-5 min) resolution. Nanoparticle formulations with surfactants (Silwet L-77) that reduced surface tension to 22 mN/m were found to be crucial for enabling rapid uptake (<10 min) of nanoparticles through the leaf stomata and cuticle pathways. Nanoparticle-leaf interaction (NLI) empirical models based on hydrodynamic size and ζ potential indicate that hydrophilic nanoparticles with <20 and 11 nm for cotton and maize, respectively, and positive charge (>15 mV), exhibit the highest foliar delivery efficiencies into guard cells (100%), extracellular space (90.3%), and chloroplasts (55.8%). Systematic assessments of nanoparticle-plant interactions would lead to the development of NLI models that predict the translocation and distribution of nanomaterials in plants based on their chemical and physical properties.
对纳米颗粒与植物叶片之间相互作用的基本和定量理解对于推动纳米农业领域的发展至关重要。在此，我们系统地研究并建立了模型，以探讨亲水性纳米颗粒的ζ电位（-52.3 mV至+36.6 mV）和流体动力学尺寸（1.7 - 18 nm）如何影响向特定叶细胞和细胞器的递送效率及途径。我们研究了具有农业应用价值的纳米颗粒，包括碳点（CDs，0.5和5 mg/mL）、氧化铈（CeO，0.5 mg/mL）和二氧化硅（SiO，0.5 mg/mL）纳米颗粒与两种具有不同叶片解剖结构的主要作物叶片的相互作用：棉花（双子叶植物）和玉米（单子叶植物）。生物相容性碳点能够通过共聚焦荧光显微镜在高空间分辨率（约200 nm）和时间分辨率（2 - 5分钟）下实时追踪纳米颗粒的转运和分布。发现添加了将表面张力降低至22 mN/m的表面活性剂（Silwet L - 77）的纳米颗粒制剂对于使纳米颗粒能够通过叶片气孔和角质层途径快速吸收（<10分钟）至关重要。基于流体动力学尺寸和ζ电位的纳米颗粒 - 叶片相互作用（NLI）经验模型表明，对于棉花和玉米，分别具有小于20和11 nm且带正电荷（>15 mV）的亲水性纳米颗粒，对保卫细胞（100%）、细胞外空间（90.3%）和叶绿体（55.8%）表现出最高的叶面递送效率。对纳米颗粒 - 植物相互作用的系统评估将导致开发基于纳米材料化学和物理性质预测其在植物中转运和分布的NLI模型。
