Hop Polyphenols in Relation to Verticillium Wilt Resistance and Their Antifungal Activity

Abstract

(1) Background: Verticillium wilt (VW) of hop is a devastating disease caused by the soil-borne fungi Verticillium nonalfalfae and Verticillium dahliae. As suggested by quantitative trait locus (QTL) mapping and RNA-Seq analyses, the underlying molecular mechanisms of resistance in hop are complex, consisting of preformed and induced defense responses, including the synthesis of various phenolic compounds. (2) Methods: We determined the total polyphenolic content at two phenological stages in roots and stems of 14 hop varieties differing in VW resistance, examined the changes in the total polyphenols of VW resistant variety Wye Target (WT) and susceptible Celeia (CE) on infection with V. nonalfalfae, and assessed the antifungal activity of six commercial phenolic compounds and total polyphenolic extracts from roots and stems of VW resistant WT and susceptible CE on the growth of two different V. nonalfalfae hop pathotypes. (3) Results: Generally, total polyphenols were higher in roots than stems and increased with maturation of the hop. Before flowering, the majority of VW resistant varieties had a significantly higher content of total polyphenols in stems than susceptible varieties. At the symptomatic stage of VW disease, total polyphenols decreased in VW resistant WT and susceptible CE plants in both roots and stems. The antifungal activity of total polyphenolic extracts against V. nonalfalfae was higher in hop extracts from stems than those from roots. Among the tested phenolic compounds, only p-coumaric acid and tyrosol markedly restricted fungal growth. (4) Conclusions: Although the correlation between VW resistance and total polyphenols content is not straightforward, higher levels of total polyphenols in the stems of the majority of VW resistant hop varieties at early phenological stages probably contribute to fast and efficient activation of signaling pathways, leading to successful defense against V. nonalfalfae infection.

Effect of Alternate Wetting and Drying Irrigation on the Nutritional Qualities of Milled Rice

“…For example, cinnamic acid is induced by beneficial Rhizobia bacteria in rice and is implicated in resistance to Rhizoctonia (Mishra et al, 2006 ). Another polyphenol called tyrosyl was shown to have very potent antifungal activity not only in plant diseases but also in human infections (Abdel-Rhman et al, 2020 ; Berne et al, 2020 ). Sinapinaldehyde or Sinapyl aldehyde is another class of antifungal compound produced naturally in plants.…”

An Oxidoreductase-like Protein is Required for Verticillium dahliae Infection and Participates in the Metabolism of Host Plant Defensive Compounds

“…Plant phenolics originate from the phenylpropanoid and polyketide pathways, or a combination of both, and can directly inhibit the growth of pathogenic fungi . Phenolic acids were extracted from cotton plants infected with different V.…”

“…Plant phenolics originate from the phenylpropanoid and polyketide pathways, or a combination of both, and can directly inhibit the growth of pathogenic fungi. 27 Phenolic acids were extracted from cotton plants infected with different V. dahliae strains and detected via HPLC. The results indicated that the content of phenolic acids in the ΔVdOrlp-infected cotton roots were significantly lower than that in the V991-or VdOrlp OE -inoculated roots (Figure 6A).…”

The application of plant growth-promoting rhizobacteria in Solanum lycopersicum production in the agricultural system: a review

“…In particular, plants have promoted their defense mechanism to fight invading spoilage organisms ( Köhl, Kolnaar & Ravensberg, 2019 ). Some plant genes are RNA-seq responsible for defense against a plant root spoilage organism, Verticillium dahlia ( Berne et al, 2020 ). They produced a plant-based signal transduction pathway web, which was initiated to acknowledge elicitors with safety indication materials and Pathogen-Associated Molecular Patterns that observe microbes like those that essentially relate to the roots of the plant in their soil habitat.…”