Salicylic acid (SA) is a phytohormone with a central role in plant protection against various types of stresses. Exogenous application of SA in plants often requires a fine adjustment of the pH in the applied solution as well as frequent foliar sprays with a rigorous handling of doses. This work investigates the preparation and characterization of nanocomposites composed of bentonite clays (Bent) and SA as bio-active to produce an efficient and stable hormonal formulation to be used in agriculture. Bent-SA was obtained via cationic exchange reactions of natural Bent with an aqueous solution of SA. The physicochemical properties of Bent-SA were studied in terms of Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD) and Thermogravimetric Analysis (TGA). SA was intercalated in a 3.65% w/w interacting by electrostatic forces between Bent layers. The SA protective activity was investigated in Pseudomonas syringae pv. tomato DC3000 (Pto)-infected tomato plants (Solanum lycopersicum). The expression levels of pathogenesis-related proteins (PRs) were measured by real time quantitative RT-PCR. The genes PR1 and PR5 were up-regulated 2.2- and 1.23-fold, respectively, in 24 h-treated Bent-SA plants. Furthermore, PR3 protein level increased locally and systemically by Bent-SA treatment in plant tissues. The plant disease incidence was significantly reduced in Bent-SA pretreated seedlings. Analyses of DR5:GUS transgenic reporter tomato lines showed that Bent-SA effectiveness was preserved after vehiculization. It was concluded that Bent-SA can provide an environmentally friendly strategy to control tomato plants against Pto bacterial infection.

水杨酸（SA）是一种植物激素，在植物防御各种胁迫中起着核心作用。在植物中外源施用SA通常需要对所施用溶液的pH值进行精细调节，并且需要经常进行严格控制剂量的叶面喷雾。这项工作研究了由膨润土（Bent）和SA组成的纳米复合物的制备和表征，该复合物具有生物活性，可生产出高效稳定的农业用激素制剂。Bent-SA是通过天然Bent与SA水溶液的阳离子交换反应获得的。通过傅立叶变换红外光谱（FTIR），X射线衍射（XRD）和热重分析（TGA）研究了Bent-SA的理化性质。SA插在3.65％w/ w通过弯曲层之间的静电力相互作用。在丁香假单胞菌pv中研究了SA的保护活性。番茄DC3000（Pto）感染的番茄植株（茄子）。通过实时定量RT-PCR测量发病机理相关蛋白（PRs）的表达水平。在处理24小时的Bent-SA植物中，基因PR1和PR5分别上调了2.2倍和1.23倍。此外，通过Bent-SA处理植物组织中的PR3蛋白水平局部和全身性增加。在Bent-SA预处理的幼苗中，植物病害发生率显着降低。DR5：GUS的分析转基因报道番茄株系表明，弯曲后，Bent-SA的功效得以保留。结论是，Bent-SA可以提供一种环境友好的策略来控制番茄植株免受Pto细菌感染。