Copper sulphate pentahydrate cuso4.5h2o

Amorphous silica NPs ~20 nm in diameter were prepared using rice husk ash as per the procedure of Sankar et al. [29 (link)] with a few modifications. The detail of the synthesis of the SiO₂ NPs was described in our previous report [30 (link)]. Other chemicals, including copper sulphate pentahydrate (CuSO₄.5H₂O, 98%) and hydrazine mono hydrate (N₂H₄.H₂O, 80%), were purchased from Merck (Darmstadt, Hesse, Germany). Carboxymethyl cellulose (CMC) and ammonium hydroxide (NH₄OH, 25%) were purchased from Xilong Scientific Company (Shantou, Guangdong, China). The P. capsici was supplied by the Pepper Research and Development Centre, Western Highland Agriculture and Forestry Science Institute (Buon Ma Thuot City, Dak Lak, Vietnam).

All the chemicals and reagents used in the experiment were of analytical grade. Copper sulphate pentahydrate CuSO₄,5H₂O, Ascorbic acid C₆H₈O₆ and Sodium hydroxide NaOH were purchased from Merck and Gum Arabic sample was received from ICAR-CAZRI, Jodhpur and used as received without further purification. De-ionized water was used for all the experiments.

E3 medium (0.5 mM NaCl, 0.017 mM KCl, 0.033 mM CaCl₂, 0.033 mM MgSO₄, pH 7.0–7.4) was used to prepare all solutions. Copper sulphate pentahydrate (CuSO₄.5H₂O) (Merck, S.A., Algés, Portugal) was used as the source of copper and a stock solution of 4 mM (1000 mg/L) was prepared in ultra-pure water and further diluted in E3 medium to 10 µM (2.5 mg/L) [27 (link)]. Tricaine methanesulfonate (MS-222) (Sigma Aldrich, Lisboa, Portugal) stock solution of 5.74 mM (1500 mg/L) was prepared in buffered water, pH was adjusted to 7.4 and diluted in E3 medium to 574 µM (150 mg/L), according to [28 (link),29 (link)]. Diclofenac (DIC) sodium salt (Alfa Aesar, Kandel, Germany) stock solution was prepared in E3 medium at 2 mM (636 mg/L) and diluted to 1.5 µM (4.75 mg/L) [26 (link)]. THY (5-methyl-2-propan-2-ylphenol) (Sigma Aldrich) stock solution was prepared in ultra-pure water containing 10% ethanol and diluted in E3 medium of 430 µM (64.5 mg/L) and further diluted to 20 µM (3 mg/L). A 20 µM (9.6 mg/L) stock solution of 24-EPI (Sigma Aldrich, Lisboa, Portugal) was prepared in ultra-pure water containing 5% ethanol and diluted to 5 µM (2.4 mg/L) in E3 medium. All other reagents used were purchased from Sigma Aldrich (Lisboa, Portugal) or of the highest commercially available grade.