In vitro Antifungal Activity of a New Bioproduct Obtained from Grape Seed Proanthocyanidins on Botrytis cinerea Mycelium and Spores

Abstract

Botrytis cinerea is a necrotrophic fungus that affects over 200 plant species. In vineyards, this pathogen is responsible for one of the most important diseases, commonly known as botrytis bunch rot or grey mould. Keeping infection under control with synthetic fungicides leads to an increased biological resistance of pathogen populations. An alternative way to synthetic products is to obtain natural fungicides by using bioactive compounds of plants. This study focuses on the antifungal properties of a new bioproduct obtained from polymeric proanthocyanidins extracted from grape seeds of ‘Fetească neagră’ variety. The bioproduct in solid state presented a total content of polyphenols of 0.625 mg GAE mg-1, a polyphenolic index of 17.40 and an antioxidant activity of 91.27% scavenged DPPH. The bioproduct with polyphenolic structure showed a moderate effect on the radial growth of fungal mycelium, at EC50 values between 11.23 and 12.15 mg mL-1. Effective antifungal activity was showed in the inhibition of spore germination, where the EC50 values varied from 1.14 to 1.47 mg mL-1. These in vitro results sustain the possibility of including the bioproduct in the category of natural fungicides for biological control against Botrytis cinerea fungus.

Characterization of grape marc hydrolysates and their antifungal effect against phytopathogenic fungi of agricultural importance

“…These phenolic acids probably caused damages to the mycelial structure of F. oxysporum, as previously mentioned, and reduced its growth. Other studies have highlighted that phytopathogen inhibition mechanisms vary depending on phenolic compounds and the fungi tested (Nechita et al, 2019;Joaquín-Ramos et al, 2020). In this study, a different trend was observed for Alternaria spp.…”

“…In addition, damages to the mycelial structure of F. oxysporum exposed to hydrolysates of RGM seeds, PGM seeds and WGM seeds were observed using microscopic examinations (Figure 2). According to previous reports, phenolic compounds including simple molecules (phenolic acids) and complex structures (flavanols, flavonols and anthocyanins) have been reported to be directly involved in the defence mechanisms of plants against pathogenic fungi (Ahmed et al, 2017;Nechita et al, 2019). In addition, Luo et al (2016) confirmed that phenolic compounds could increase the cell permeability, thus reducing fungal growth.…”

The Antimicrobial Activities of Silver Nanoparticles from Aqueous Extract of Grape Seeds against Pathogenic Bacteria and Fungi

“…In accordance with our findings, a previous study showed that the ethanolic extract of grapefruit tendrils had a significant fungicidal effect against different Fusarium species such as F. oxysporum , F. culmorum , F. solani , F. coeruleum , F. sporotrichioides , F. verticillioides , and F. tabacinum, while another species, Rhizoctonia solani, showed significant resistance [ 44 ]. Another study showed that polymeric proanthocyanidins isolated from grape seeds by ethanolic extraction had significant antifungal activity against Botrytis cinerea by inhibiting the spore germination [ 45 ]. Another study showed that the lonely application of GSE did not induce any inhibition of the mycelial growth of A. alternata [ 46 ].…”

Arbuscular mycorrhizal fungi inhibit necrotrophic, but not biotrophic, aboveground plant pathogens: a meta‐analysis and experimental study

“…The polyphenol content in G. max and M. sativa significantly increased following AMF inoculation. This class of New Phytologist chemicals has been widely reported to be protective against necrotrophic pathogens (Haile et al, 2017;Nechita et al, 2019). For example, a polyphenol bioproduct inhibited spore germination and mycelial growth in the necrotrophic pathogen Botrytis cinerea (Nechita et al, 2019).…”

“…This class of chemicals has been widely reported to be protective against necrotrophic pathogens (Haile et al ., 2017; Nechita et al ., 2019). For example, a polyphenol bioproduct inhibited spore germination and mycelial growth in the necrotrophic pathogen Botrytis cinerea (Nechita et al ., 2019). Additionally, increases in foliar N (as observed in our study) could increase tolerance to necrotrophs such as Alternaria and Fusarium , because plants suffering from nitrogen limitation have a lower photosynthetic rate and slower growth, increasing their susceptibility (Snoeijers et al ., 2000; Fagard et al ., 2014).…”