Laura Mugnai | Università degli Studi di Firenze (University of Florence) (original) (raw)

Papers by Laura Mugnai

Journal of Fungi

Fomitiporia mediterranea (Fmed) is the primary Basidiomycota species causing white rot in Europea... more Fomitiporia mediterranea (Fmed) is the primary Basidiomycota species causing white rot in European vineyards affected by the Esca complex of diseases (ECD). In the last few years, an increasing number of studies have highlighted the importance of reconsidering the role of Fmed in ECD etiology, justifying an increase in research interest related to Fmed’s biomolecular pathogenetic mechanisms. In the context of the current re-evaluation of the binary distinction (brown vs. white rot) between biomolecular decay pathways induced by Basidiomycota species, our research aims to investigate the potential for non-enzymatic mechanisms adopted by Fmed, which is typically described as a white rot fungus. Our results demonstrate how, in liquid culture reproducing nutrient restriction conditions often found in wood, Fmed can produce low molecular weight compounds, the hallmark of the non-enzymatic “chelator-mediated Fenton” (CMF) reaction, originally described for brown rot fungi. CMF reactions c...

Crop Protection, 2017

The use of several microbial biocontrol agents to combat Botrytis cinerea, the causal agent of gr... more The use of several microbial biocontrol agents to combat Botrytis cinerea, the causal agent of grey mould, has been studied. However, only a few microorganisms have been developed as biofungicides, which are currently used in some countries, mostly in organic farming. The main reason for the limited market uptake of microbial biofungicides is their debated variable efficacy. To cope with poor survival in the canopy, due to unfavourable environmental conditions or their intrinsic lower level of disease control compared to synthetic chemical fungicides, use of a mixture of two or more microorganisms with different environmental requirements and mechanisms of action has been proposed with contrasting results. However, their use in strategies involving calculated timing of the microbial biocontrol agents, taking into consideration their mechanism of action in relation to the epidemiology and pathogenesis of the disease, has never been attempted in relation to combating grey mould on grapes. The results of four years of trials in three locations in Northern and Central Italy show that Trichoderma atroviride, Aureobasidium pullulans and Bacillus subtilis, applied at bunch-closure, veraison and pre-harvest, respectively, controlled B. cinerea on bunches very satisfactorily, and the results did not differ from those obtained with a strategy combining the three biofungicides, applied at the aforementioned stages. Colonisation of berries by each of the different microbial biocontrol agents at harvest time did not differ for individual treatments or when applied in the combined strategy, suggesting that the microorganisms did not negatively interfere with each other and that they may possibly occupy different ecological niches. The high level of efficacy of the tested biocontrol agents against grey mould can be explained with the relatively low-medium level of the disease, their integration with agronomic practices or the optimal timing of the treatment.

Journal of Plant Pathology, 2017

Journal of Plant Pathology, 2011

Frontiers in Plant Science

Grapevine grafting is an essential practice in viticulture and over the years, various bench graf... more Grapevine grafting is an essential practice in viticulture and over the years, various bench grafting techniques have been developed to mechanize the nursery process and to increase the yield in number of viable cuttings. Bench grafting is a fundamental nursery practice that can potentially affect the quality of propagation material also in young decline associated to grapevine trunk diseases and has been recently reported to influence leaf symptoms development associated with diseases of Esca complex. The study aimed to investigate how three bench grafting methods [i.e., (i) Omega graft as mechanical technique, (ii) Whip and Tongue graft as manual technique and (iii) Full Cleft graft as semi-mechanical technique] can influence these phenomena. Specifically, the different methods were compared for their effect on the anatomical development of the grafting point and the functionality of the xylem, also considering two factors: the grapevine cultivar (Cabernet Sauvignon, Glera and Ter...

Sustainability and circular economy are increasingly pushing for the search of natural materials ... more Sustainability and circular economy are increasingly pushing for the search of natural materials to foster antiparasitic treatments, especially in the case of economically relevant agricultural cultivations, such as grapevine. In this work, we propose to deliver neem oil, a natural biopesticide loaded into novel nanovectors (nanocapsules) which were fabricated with a scalable procedure starting from Kraft lignin and grapeseed tannins. The ensuing formulations were characterized in terms of size and Zeta potential, showing that almost all the nanocapsules had size in the suitable range for delivery purposes (mean diameter 150-300 nm), with low polydispersity and sufficient stability to ensure long shelf life. The target microorganisms were three reference fungal pathogens of grapevine (Botrytis cinerea, Phaeoacremonium minimum, Phaeomoniella chlamydospora), responsible for recurrent diseases on this crop: grey mold or berry rot by B. cinerea and diseases of grapevine wood within the ...

Grapevine trunk diseases (GTDs) are one of the most serious biotic stresses affecting this import... more Grapevine trunk diseases (GTDs) are one of the most serious biotic stresses affecting this important crop. Among them a range of diseases were identified and associated to a plethora of phytopathogenic fungi, including species of Diaporthe. Diaporthe eres was recently identified as one of the species involved in cane blight of grapevine. The ability of a strain of this fungus isolated from infected grapevine plant in Italy to produce in vitro phytotoxic metabolites was investigated. Five phytotoxic metabolites were identified by their physical and spectroscopic properties as 4-hydroxybenzaldehyde, 4-hydroxybenzoic acid, nectriapyrone, p-cresol and tyrosol. When tested on grapevine leaf disks and by leaf absorption, 4-hydroxybenzoic acid induced symptoms on both disks and leaves, 4-hydroxybenzaldehyde and p-cresol showed, respectively, phytotoxicity on leaf disks and on the leaf absorption ...

Phytopathologia Mediterranea, 2019

Botryosphaeria dieback (BD) is an important trunk disease affecting grapevines. Several Lasiodipl... more Botryosphaeria dieback (BD) is an important trunk disease affecting grapevines. Several Lasiodiplodia species have been shown to be involved in BD affecting the perennial organs of grapevine, mainly causing cankers. ( R )-(-)-mellein and tyrosol, two well-known fungal phytotoxins, were isolated from the organic extract of culture filtrate of Lasiodiplodia laeliocattleyae (syn. egyptiacae ), which had been isolated from grapevines affected by BD in Brazil. This increases knowledge of the secondary metabolites produced by Lasiodiplodia species, confirming that ( R )-(-)-mellein is a toxin typically produced by Botryosphaericeae species.

Frontiers in Plant Science, 2021

Grapevine trunk diseases (GTDs) are a serious and growing threat to vineyards worldwide. The need... more Grapevine trunk diseases (GTDs) are a serious and growing threat to vineyards worldwide. The need for innovative control tools persists since pesticides used against some GTDs have been banned and only methods to prevent infections or to reduce foliar symptoms have been developed so far. In this context, the application of imaging methods, already applied to study plant–microbe interactions, represents an interesting approach to understand the effect of experimental treatments applied to reduce fungal colonization, on GTD-related pathogens activity. To this aim, trials were carried out to evaluate the efficacy of copper-based treatments, formulated with hydroxyapatite (HA) as co-adjuvant with innovative delivery properties, loaded with two different copper(II) compounds (tribasic sulfate and sulfate pentahydrate), and applied to grapevine propagation material to inhibit fungal wood colonization. The treated rootstock (Vitis berlandieri × Vitis riparia cv. K5BB) and scion cuttings (V...

The Mediterranean region is home to about 25 000 plant species, of which 13 000 are endemic (not ... more The Mediterranean region is home to about 25 000 plant species, of which 13 000 are endemic (not found anywhere else on Earth) and has been recognised as a biodiversity hotspot that is suffering an exceptional loss of habitat. Mediterranean agriculture, forests and other environments are seriously threatened by numerous quarantine and emerging pests, and their negative impacts is expected to increase due to global trade and climate change. In the face of these challenges, the Mediterranean region is particularly vulnerable due to the weakness of national quarantine systems, limited expertise and phytosanitary infrastructures, and not least the lack of funds for research activities in support of statutory plant health. The Compendium on the 'Plant Health research priorities for the Mediterranean region' is the result of the collaboration of experts from leading organizations and initiatives in the region: the International Centre for Advanced Mediterranean Agronomic Studies, ...

fongiques*et*bactériennes*colonisant*le*bois* de*ceps*de*vigne*ayant*exprimé*ou*non* des*symptôme... more fongiques*et*bactériennes*colonisant*le*bois* de*ceps*de*vigne*ayant*exprimé*ou*non* des*symptômes*d’esca

Phytopathologia Mediterranea, 2018

Since the early 1990s, grapevine trunk diseases (GTDs) have posed threats for viticulture. Esca c... more Since the early 1990s, grapevine trunk diseases (GTDs) have posed threats for viticulture. Esca complex, Eutypa- and Botryosphaeria- diebacks, mostly detected in adult vineyards, are currently responsible for considerable economic losses in the main vine-growing areas of the world. Other GTDs, such as Petri- (Esca complex) and Black-foot diseases, are emerging problems in grapevine nurseries (resulting in grafting failures and/or loss of saleable plants) and in young vineyards. The impacts of GTDs in modern viticulture depend on several factors, some related to their complexity, and others linked to host plant characteristics, changes in vineyard management and to the scarcity of simple tools for their control. For these reasons control of GTDs remains difficult, also depending on knowledge transfer from research to field and vice versa . This paper outlines the main preventive and curative techniques currently applied, scientifically tested or not that have resulted from the outcom...

Trabajo presentado en el 10th International Workshop on Grapevine Trunk Diseases, celebrado en Re... more Trabajo presentado en el 10th International Workshop on Grapevine Trunk Diseases, celebrado en Reims (Francia), del 4 al 7 de julio de 2017