Examinando por Autor "Rocha, Felipe"

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  • Miniatura
    ÍtemAcceso Abierto
    Effects of Larrea nitida nanodispersions on the growth inhibition of phytopathogens
    (Springer, 2023-09-21) Svetaz, Laura Andrea; Sortino, Maximiliano Andrés; Rocha, Felipe; Nunes Calumby, Rodrigo José; Teixeira Ribeiro Vidigal, Márcia Cristina; Campos Bermúdez, Valeria Alina; Rius, Sebastián Pablo; https://orcid.org/0000-0002-1023-1641; https://orcid.org/0000-0002-4271-1690
    Larrea nitida Cav. (Zygophyllaceae) is a plant endemic to Argentina and Chile, and its extract has been studied over the last years due to the presence of antimicrobial agents that can be used to control the growth of some pathogens in agriculture. However, the extract is highly hydrophobic, which strongly affects its fungicidal activity in aqueous media. In this sense, the solid dispersion technique was used to produce L. nitida extract nanodispersions with polyethylene glycol (PLE) and with polyethylene glycol and zinc acetate (PZLE). In order to further evaluate the activity of the extract in PLE and PZLE, blank nanodispersions containing only polyethylene glycol (PEG) and zinc acetate (PZ) without the addition of the extract were also produced. The fungicidal activity of the water-soluble nanoparticles was evaluated at different concentrations (0.037–0.110 g.mL−1). In general, the nanoparticles were successfully produced on a nanometric size and presented a significant inhibitory activity on the growth of the pathogens Fusarium oxysporum and Fusarium verticillioides in aqueous media. Compared to PLE, PZLE presented increased fungistatic activity, possibly due to their increased solubility in water. Even though their application in agriculture should be further investigated, the nanodispersions present great potential to be applied as a green biotechnological tool.
  • Miniatura
    ÍtemAcceso Abierto
    Larrea nitida extract-loaded nanodispersions as a novel bio-stimulant for tomato plants
    (Elsevier, 2024-12-05) Rocha, Felipe; Svetaz, Laura Andrea; Sortino, Maximiliano Andrés; Campos Bermúdez, Valeria Alina; Rius, Sebastián Pablo
    Larrea nitida Cav. (Zygophyllaceae) hydrophobic extract (LE) is rich in antimicrobial and antioxidant compounds. In our previous study, water-soluble nanodispersions without (PZ) and with LE (PZLE) were produced to facilitate their application in agriculture. The foliar treatment was carried out with water (control), PZ and PZLE thrice a week at concentrations of 33 and 100 mg.L− 1 on 1-week-old tomato seedlings (Solanum lycopersicum L. variety perita platensis). PZLE at a concentration of 100 mg.L− 1 significantly induced a growth promotion effect and decreased the activity of the antioxidant enzymes guaiacol peroxidase (GPx) and catalase (CAT), probably due to the presence of antioxidant compounds in PZLE. However, 5 days after infection with Pseudomona syringae pv. tomato, the activity of CAT increased by 73 % compared to the control, as a response to the stress caused by the infection. Additionally, plants treated with PZLE at 33 and 100 mg.L− 1 exhibited reductions in infection symptoms of 44 % and 76 %, respectively. As for both concentrations of PZ, no significant differences were found when compared to the control, suggesting a protective effect of PZLE. The photosynthetic parameters of the plants, such as Phi2 (φPSII), non-photochemical quenching (NPQ) and the relative chlorophyll in the leaves of these plants remained unaffected, suggesting no detrimental effects of PZLE on photosynthetic efficiency. PZLE demonstrates potential as a bio-stimulant for tomato plants, offering a complementary approach to traditional agricultural inputs.