Abstract：
Xylella fastidiosa (Xf) is a quarantine plant pathogen capable of colonizing the xylem of a wide range of hosts. Currently, there is no cure able to eliminate the pathogen from a diseased plant, but several integrated strategies have been implemented for containing the spread of Xf. Nanotechnology represents an innovative strategy based on the possibility of maximizing the potential antibacterial activity by increasing the surface-to-volume ratio of nanoscale formulations. Nanoparticles based on chitosan and/or fosetyl-Al have shown different in vitro antibacterial efficacy against Xf subsp. fastidiosa (Xff) and pauca (Xfp). This work demonstrated the uptake of chitosan-coated fosetyl-Al nanocrystals (CH-nanoFos) by roots and their localization in the stems and leaves of Olea europaea plants. Additionally, the antibacterial activity of fosetyl-Al, nano-fosetyl, nano-chitosan, and CH-nanoFos was tested on Nicotiana tabacum cultivar SR1 (Petite Havana) inoculated with Xff, Xfp, or Xf subsp. multiplex (Xfm). The bacterial load was evaluated with qPCR, and the results showed that CH-nanoFos was the only treatment able to reduce the colonization of Xff, Xfm, and Xfp in tobacco plants. Additionally, the area under the disease progress curve, used to assess symptom development in tobacco plants inoculated with Xff, Xfm, and Xfp and treated with CH-nanoFos, showed a reduction in symptom development. Furthermore, the twitching assay and bacterial growth under microfluidic conditions confirmed the antibacterial activity of CH-nanoFos.
摘要：
Fastidiosa（Xf）是一种能够在多种宿主的木质部定殖的检疫植物病原体。目前,无法从患病的植物中消除病原体，而已经实施了几种综合策略来遏制Xf的传播。纳米技术代表了一种创新策略，该策略基于通过增加纳米级制剂的表面与体积比来最大化潜在抗菌活性的可能性。基于壳聚糖和/或Fosetyl-Al的纳米颗粒对Xf亚种fastidiosa（Xff）和pauca（Xfp）显示出不同的体外抗菌功效。这项工作证明了根对壳聚糖涂层的Fosetyl-Al纳米晶体（CH-nanoFos）的吸收及其在欧洲油菜籽植物的茎和叶中的定位。此外,Fosetyl-Al的抗菌活性，纳米Fosetyl,纳米壳聚糖，并在烟草cv上测试了壳聚糖涂层的Fosetyl-Al纳米晶体（CH-nanoFos）。SR1（小哈瓦那）接种Xff，Xfp,或Xf子sp。多路复用（XFM）。用qPCR评估细菌载量，结果表明，CH-nanoFos是唯一能够减少Xff定植的治疗方法，Xfm,和Xfp在烟草植物中。此外,疾病进展曲线下的面积（AUDPC），用于评估接种Xff的烟草植物的症状发展，Xfm,和Xfp并用CH-nanoFos治疗，显示症状发展减少。此外，微流控条件下的抽搐试验和细菌生长证实了CH-nanoFos的抗菌活性。
