Chemical and Spectroscopic Characteristics of the Wood ofVitis viniferaCv. Sangiovese Affected by Esca Disease

Abstract

Chemical and spectroscopic analyses ((13)C cross-polarization-magic angle spinning NMR and attenuated total reflection Fourier transform infrared spectroscopies) were carried out on the wood of Vitis vinifera cv. Sangiovese with brown-red discoloration and black streaks caused by esca disease. The analyses of the brown-red wood revealed the destruction of hemicelluloses and noncrystalline cellulose as well as modifications in the pectic and ligninic wood fractions. The pectic fraction consisted of carbohydrates associated with polyphenols. The lignin fraction exhibited only a few changes in the aromatic systems and a partial demethylation, and it appeared to be associated with condensed phenolic components probably arising from response polyphenols. The degradation of hemicelluloses and noncrystalline cellulose in brown-red wood, where the pathogens Phaeoacremonium aleophilum and Phaeomoniella chlamydospora prevail with respect to the other fungus Fomitiporia mediterranea, was consistent with reports on the degradative activity of such fungi in vitro carried out on model substrates. The observed alterations could also be attributed to the radical oxidation process caused by the oxidative response of defense itself triggered by infection, as suggested by the accumulation of postinfectional compounds. The analyses of wood tissue with black streaks showed less marked deterioration; here, an increase in pectic and phenolic substances, which probably accumulate in the xylem vessels as a response to the infection, was observed.

Response of Vitis vinifera cell cultures to Phaeomoniella chlamydospora: changes in phenolic production, oxidative state and expression of defence-related genes

“…Resveratrol functions as a precursor of viniferins, which are dimers and oligomers of resveratrol formed by an oxidative dehydrogenation condensation process (Amalfitano et al 2000;Langcake 1981). Furthermore, our results seem to agree with those obtained in vivo, since it was described an increase in the production of trans-resveratrol and ε-viniferin in wood of grapevines showing esca symptoms, as well as an increase in phenolic compounds in esca-diseased leaves (Amalfitano et al 2000;Agrelli et al 2009;Lima et al 2010). Nonetheless, and considering the complexity that characterizes esca (a disease in which additional factors other than fungi may interfere), the possibility that an increase in stilbenic production might be not sufficient to fight the disease cannot be discounted.…”

Susceptibility of Cultivated and WildVitisspp. to Wood Infection by Fungal Trunk Pathogens

“…Several studies have investigated the nature of chemicals present in the reaction zone of grapevine wood infected with trunk pathogens. Also, comparisons of total phenolic concentrations of woody tissues degraded by the Esca pathogens indicate that these compounds may restrict fungal colonization of tbe wood (1). Also, comparisons of total phenolic concentrations of woody tissues degraded by the Esca pathogens indicate that these compounds may restrict fungal colonization of tbe wood (1).…”

Cervical spondylitis due to Phaeoacremonium venezuelense in an immunocompetent patient. A first case report

“…Phaeoacremonium are fungi which the main environmental source are woody plants especially in grapevine and are known as a causal agent of grapevine diseases such as Petri disease and esca, which can cause leaf drop and wood discoloration [1][2][3][5][6][7][8][9]11,12,23,[24][25][26][27]. To date about 20 species of Phaeoacremonium have been isolated.…”

“…Phaeoacremonium species are fungi whose main environmental source is woody plants [1,2,5,[9][10][11][12]14,22,23]. They have been recently isolated from human patients as etiologic agent of opportunistic human infection [1,3,5,8,9].…”