Nanoencapsulation Boosts the Copper-Induced Defense Responses of a Susceptible <i>Coffea arabica</i> Cultivar against <i>Hemileia vastatrix</i>

• Main Authors: Diego G. Gomes (Author), Karina Sanada (Author), Joana C. Pieretti (Author), Luciana H. Shigueoka (Author), Gustavo H. Sera (Author), Amedea B. Seabra (Author), Halley C. Oliveira (Author)
• Format: Book
• Published: MDPI AG, 2023-01-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.
• Notes: 10.3390/antibiotics12020249; 2079-6382
• Keywords: coffee rust; chitosan nanoparticles; biopolymers; disease management; nanotechnology; copper ions; Therapeutics. Pharmacology; RM1-950
• Source: Antibiotics, Vol 12, Iss 2, p 249 (2023)

Due to the environmental risks of conventional Cu-based fungicides, Cu-loaded chitosan nanoparticles have been developed as nano-pesticides, aiming to protect plants against different diseases. In this sense, the objective was to verify the effects of chitosan nanoparticles containing Cu²⁺ ions on leaf discs of <i>Coffea arabica</i> cv. IPR 100 infected with <i>Hemileia vastatrix</i>. The treatments were water as a control (CONT), unloaded chitosan nanoparticles (NP), chitosan nanoparticles containing Cu²⁺ ions (NPCu), and free Cu²⁺ ions (Cu). Different concentrations of NP (0.25; 0.5; 1 g L⁻¹) and Cu²⁺ ions (1.25; 2.5; 5 mmol L⁻¹) were tested. The severity of the coffee rust was 42% in the CONT treatment, 22% in NP, and 2% in NPCu and Cu. The treatments protected coffee leaves; however, NPCu stood out for initial stress reduction, decreasing Cu phytotoxicity, promoting photosynthetic activity maintenance, and increasing antioxidant responses, conferring significant protection against coffee rust. At low concentrations (1.25 mmol L⁻¹), NPCu showed higher bioactivity than Cu. These results suggest that Cu-loaded chitosan nanoparticles can induce a more significant plant defense response to the infection of <i>Hemileia vastatrix</i> than conventional Cu, avoiding the toxic effects of high Cu concentrations. Thus, this nanomaterial has great potential to be used as nano-pesticides for disease management.