Nanoparticles and photodynamic therapy in the treatment and control of Alternaria alternata in wheat seeds

Abstract

The expansion of wheat crops (Triticum spp.) to the Brazilian Cerrado highlights the need to use pathogen-free seeds. This study aimed at evaluating the efficacy of nanoparticles (NPs) and photodynamic therapy (PhT) in inhibiting the in vitro growth of the fungus Alternaria alternata, in its treatment and control in naturally contaminated wheat seeds, and in the physiological quality of the seeds. The efficacy of NPs (ZnOCl, ZnOCl:1Cu, ZnOCl:0.1Ag; ZnO:1Cu, ZnO, and ZnO:1Ag) and PhT using methylene blue (MB) and toluidine blue (TB) dyes was evaluated in inhibiting the mycelial growth of A. alternata and in the treatment and control of the pathogen in wheat seeds by evaluating germination, emergence, GSI, ESI, accelerated ageing, and health. All NPs at 2.5 and 5 mg mL-1 concentrations and the dyes MB, TB, MB + TB at 50 and 100 µmol L-1 inhibited mycelial growth and reduced the incidence of A. alternata in the seeds. The NP ZnO:1Ag at 5 mg mL-1 and the MB + TB dye at 100 µmol L-1 were the most effective in inhibiting mycelial growth. NPs and PhT did not affect the physiological quality of seeds and controlled A. alternata in wheat seeds, demonstrating potential use in the treatment and control of the pathogen in wheat seeds.

Simonkolleite nanoparticles for seed treatment and control of tomato bacterial spot caused by Xanthomonas hortorum pv. gardneri

“…The germination percentage did not differ significantly among inoculated or uninoculated tomato seeds treated with SK-NPs or control, which ranged from 94% to 97% (Table 2), and no significant difference were observed between inoculated and uninoculated seeds. Thus, the SK-NPs did not interfere in the germination of tomato seeds, and also in the wheat seeds (Duarte;Catão;Tebaldi, 2022).…”

“…The inhibition of the bacterial growth shows that SK-NPs have toxic effects on X. hortorum pv. gardneri, and also on Alternaria alternata (Duarte;Catão;Tebaldi, 2022). The antimicrobial activity of ZnO particles doped with Ag (ZnO:Ag) was observed on Pantoea ananatis at 10 mg mL -1 (Mamede et al, 2022), and on Alternaria alternata at 2.5 and 5 mg mL -1 (Duarte; Catão; Tebaldi, 2022), also Cu and Ag nanoparticles were toxic to Escherichia coli, Bacillus subtilis, Staphylococcus aureus, and Ralstonia solanacearum (Ruparelia et al, 2008;Santiago et al, 2019).…”

“…Doping is a process that consists of adding new elements to the nanoparticle's structure and is a form of adjusting the properties of functional oxides by altering their physical and electronic structure and changing their chemical characteristics (Kwon et al, 2016). ZnOCl nanoparticles doped with Ag, and Cu inhibited Alternaria alternata growth in vitro and reduced the pathogen in wheat seeds (Duarte;Catão;Tebaldi, 2022).…”

Dickeya zeae, Pantoea ananatis, and Xanthomonas vasicola pv. vasculorum: Control with the use of nanoparticles

“…Several reviews provide insight into the latest developments in nanoparticle research (Coelho et al, 2024;Lade et al, 2019;Vurro et al, 2019;Kitherian 2016;Fernandes et al, 2014;Gogos, Knauer, & Bucheli, 2012). Recently, nanoparticles (NPs) have attracted considerable attention as an innovative alternative for the control of bacterial diseases owing to their bactericidal activity (Oliveira et al, 2023;Duarte, Catão, & Tebaldi, 2022;Mamede et al, 2022;Fraga et al, 2021;Silva et al, 2021;Qi et al, 2020).…”