Antiviral, antifungal, and insecticidal activities of Eucalyptus bark extract: HPLC analysis of polyphenolic compounds.

Autor: Abdelkhalek A; Plant Protection and Bimolecular Diagnosis Department, ALCRI, City of Scientific Research and Technological Applications, New Borg El Arab, Alexandria, 21934, Egypt., Salem MZM; Forestry and Wood Technology Department, Faculty of Agriculture (El-Shatby), Alexandria University, Alexandria 21545, Egypt., Kordy AM; Plant Protection Department, Faculty of Agriculture (Saba Basha), Alexandria University, Alexandria 21531, Egypt., Salem AZM; Facultad de Medicina Veterinaria Zootecnia, Universidad Autónoma del Estado de México, Estado de México, Instituto Literario, 50000 Toluca, México. Electronic address: salem@uaemex.mx., Behiry SI; Agricultural Botany Department, Faculty of Agriculture (Saba Basha), Alexandria University, Alexandria 21531, Egypt.
Jazyk: angličtina
Zdroj: Microbial pathogenesis [Microb Pathog] 2020 Oct; Vol. 147, pp. 104383. Date of Electronic Publication: 2020 Jul 10.
DOI: 10.1016/j.micpath.2020.104383
Abstrakt: In this study, the antiviral, antifungal, and insecticidal and HPLC analysis of polyphenolic compounds of Eucaluptus camaldulensis Dehnh. bark extract (ECBE) were evaluated. Three fungi, namely Fusarium culmorum MN398395, Rhizoctonia solani MN398397, and Botrytis cinerea MN398399 were used to colonize wood blocks of chinaberry that was previously treated with different concentrations of ECBE at 1%, 2%, and 3%. Antiviral evaluations (protective, curative, and inactivating activities) of the extract at 100 μg/mL were assayed against Tobacco mosaic virus (TMV) MG264131 using the half-leaf method to determine the inhibitory percentage towards the number of local lesions. The protective treatment of Nicotiana glutinosa leaves exhibited excellent activity (72.22%) with a 91.1-fold reduction in TMV-CP accumulation in infected tissues. Furthermore, Real-time quantitative PCR revealed that the expression level of PAL and PR-1 (salicylic acid marker) genes were significantly up regulated at four days-post inoculation (dpi) for all treatments compared to untreated leaves. The insecticidal effect was screened by the contact and fumigant methods against Tribolium castaneum (Herbst) and Sitophilus oryzae L. in vitro. In contact assay, all concentrations 1, 5, 10, 20 and 30 ppm caused 100% toxicity to the two tested pests within 24 h, whereas the fumigant assay, gave the highest mortality against T. castaneum and S. oryzae by 20 ppm (61.66%) and 30 ppm (57.77%), respectively after 24 h. The HPLC analysis of ECBE revealed that benzoic acid, quinol, salicylic acid, myricetin, and rutin were the most abundant polyphenolic compounds found in the extract. In conclusion, when the extract concentration increases, the growth of fungal mycelia was decreased compared with the control, especially against F. culmorum. According to the hypotheses of the results, the ECBE recommended to prevent the wood from discoloration, fungal molds by acting as bio-preservative, also trigger the resistance of plants against viral infection and high toxicity against stored-product insects.
(Copyright © 2020 Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
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