Exploring the potential of using bioactive plant products in the management of Fusarium oxysporum f.sp. albedinis: the causal agent of Bayoud disease on date palm (Phoenix dactylifera L.)

Abstract

Background “Bayoud” disease caused by Fusarium oxysporum f. sp. albedinis (Foa) poses a serious threat to date palm (Phoenix dactylifera L.) in Morocco. However, research studies performed to discover biological methods to control this disease remain limited. The present study has set objectives to determine antifungal activity of five plants extracts (Acacia cyanophylla, Cupressus atlantica, Eucalyptus torquata, Nerium oleander, and Schinus molle) against Foa and link this effect to their content in polyphenols and flavonoids as well as their antioxidant properties. Results Plant extracts showed significant differences (p < 0.05) regarding their antifungal activity. The extracts of E. torquata and C. atlantica showed the strongest antifungal effect resulting in the inhibition of mycelial growth, sporulation, and spore germination in a dose-dependent manner. In addition, there were significant differences among the examined plant extracts in respect to their total polyphenols (1.536–7.348 g GAE/100 g DW), flavonoids (0.986–5.759 g RE/100 g DW), and antioxidant properties measured by Trolox equivalent antioxidant capacity (TEAC) (7.47–38.97 mmol TE/100 g DW) and ferric-reducing antioxidant power (FRAP) assay (8.95–47.36 mmol TE/100 g DW). Moreover, the antifungal potential of plant extracts was found to be moderately to strongly correlated with their polyphenol and flavonoid contents as well as their antioxidant activity, implying that the effective inhibitory activity of these plant extracts is partly due to their richness in antioxidative secondary metabolites. Conclusion Our findings shed further light on plants as a-yet-untapped resource of bioactive compounds and constructed the foundation for the development of new biological approaches to best manage Bayoud disease.

Antifungal Potential of Phytochemicals against Mauginiella scaettae, the Plant Pathogen Causing Inflorescence Rot of Date Palm

“…The ability of plant extracts to inhibit mycelial growth was evaluated according to the protocol established by Bouhlali et al [ 1 ]. 5 mm mycelial discs from a 7-day-old culture of M. scaettae were transferred onto Petri dishes containing a PDA medium supplemented with different volumes of plant extracts sterilized through 0.2 μ m millipore filters to obtain 1%, 2%, 3%, and 4% serial dilutions.…”

“…The total flavonoid content (TFC) of plant material was measured according to the method previously described by Bouhlali et al [ 1 ]. A sample of five hundred microliters of diluted plant filtrate was filled up to 2500 µ L with distilled water, mixed with 150 µ L of 5% sodium nitrite and 10% aluminum chloride, and then, incubated for 5 min at ambient temperature before adding 1 mL of 1 M sodium hydroxide.…”

“…Date palm ( Phoenix dactylifera L.) has long been a primordial fruit crop in North Africa and the Middle East [ 1 ]. Beside its fundamental ecological roles in creating a suitable microclimate for growing other crops, date palm constitutes a significant source of income and offers tremendous employment opportunities to local populations helping, thereby, in preventing rural exodus.…”

“…Previous studies showed that plant-derived compounds from members of the genera of Nerium , Schinus , Eucalyptus , Cupressus , and Acacia possess potent antifungal activities against a broad spectrum of phytopathogenic fungi including Fusarium oxysporum f. sp. albedinis , the causal agent of Bayoud disease on date palm, and these properties were attributed to the antioxidant and the richness of these plants in secondary metabolites such as polyphenols and flavonoids [ 1 , 8 , 12 – 14 ]. These findings suggest potentially similar effects on M. scaettae , but data related to this topic are limited.…”

Defence response in plants and animals against a common fungal pathogen, Fusarium oxysporum

“…albedinis, F. oxysporum f. sp. cubense not known Isaac and Tahon (2014) , Bouhlali et al (2020) , Akila et al (2011) Animal derived compound showing antifungal activity Cecropin A and CecropinB, Hyalopora cecropia A. flavus, A. niger, A. fumigatus, F. moniliforme, and F. oxysporum Binds to cell wall ergosterol and cholesterol De Lucca et al (1997) Drosomycin D. melanogaster F. oxysporum not known Tian et al (2008) Metchnikowin D. melanogaster Pathogenic ascomycota, including F. graminearum not known Moghaddam et al (2017) Thanatin Podisus maculiveris Neurospora crassa, Botrytis cinerea, Nectria haematococca, Trichoderma viride, Alternaria brassicola, Fusarium culmorum, Ascochyta pisi, Fusarium oxysporum, A. fumigatus and T. mentagrophytes . Inhibition of spore germination and formation of hyphae Fehlbaum et al (1996) Dermaseptins Phyllomedusa sauvagii F. oxysporum and F. moiliformae, Aspergillus flavus, A. fumigetus, A. niger Binds to cell wall ergosterol and cholesterol De Lucca et al (1998) Myticin A and Myticin B Mytilus galloprovincialis F. oxysporum and Escherichia coli D31 not known Mitta et al (1999) Anti-fungal compound identified from other sources Iturin Bacillus velezensis Ralstonia solanacearum and Fusarium oxysporum not known Cao et al (2018) Syringomycin-E Pseudomonas spp.…”