Phenolic compounds have a role in the defence mechanism protecting grapevine against the fungi involved in Petri disease [Vitis vinifera L.]

• Published in: Phytopathologia mediterranea 2004-04, Vol.43 (1), p.87-94
• Main Authors: Río, J.A. del (Murcia Univ. (Spain). Dept. of Plant Biology), Gómez, P. (Murcia Univ. (Spain). Dept. of Plant Biology), Báidez, A. (Murcia Univ. (Spain). Dept. of Plant Biology), Fuster, M.D. (Murcia Univ. (Spain). Dept. of Plant Biology), Ortuno, A. (Murcia Univ. (Spain). Dept. of Plant Biology), Frías, V. (Agrométodos S.A., Madrid (Spain))
• Format: Article
• Language: English
• Subjects: CARIE DU BOIS; COMPOSE PHENOLIQUE; composti fenolici; COMPUESTOS FENOLICOS; CRECIMIENTO; crescita; CROISSANCE; disease resistance; ENFERMEDADES FUNGOSAS; ESPORULACION; EXPERIMENTACION IN VITRO; EXPERIMENTATION IN VITRO; fungal diseases; grapevines; growth; in vitro experimentation; INHIBICION; inhibition; inibizione; LACASA; laccase; laccasi; lignina; LIGNINAS; LIGNINE; lignins; MALADIE FONGIQUE; malattie fungine; marciume del legno; marciumi; micelio; microscopia; MICROSCOPIE; microscopy; mycelium; perossidasi; PEROXIDASAS; peroxidases; PEROXYDASE; phenolic compounds; PODREDUMBRES; POURRITURE; PUDRICION DE LA MADERA; RESISTANCE AUX MALADIES; RESISTENCIA A LA ENFERMEDAD; resistenza alle malattie; rots; SHORT NOTES; sperimentazione in vitro; sporulation; sporulazione; VID; VIGNE; vite; vitis vinifera; wood decay; xilema; xylem; XYLEME
• ISSN: 0031-9465; 1593-2095
• DOI: 10.14601/Phytopathol_Mediterr-1736

Scanning electron microscopy of stems and roots of grapevine plants affected by Petri disease demonstrated that the obstruction of xylem vessels and reduction in the flow of xylem sap, two symptoms of this disease, were mainly caused by tylose forming in the vessels and, to a lesser extent, by accumulation of aggregates. Fungal hyphae were also found in the xylem. These hyphae propagated via the xylem and invaded other vessels or adjacent parenchymatic cells through the pit. Analysis of lignin peroxidase, manganese peroxidase and laccase activity (all of which are involved in lignin degradation) in different fungi isolated from Petri disease-infected grapevines showed that Phaeoacremonium aleophilum expressed low specific activity for manganese peroxidase and high specific activity for both lignin peroxidase and laccase, while Phaeomoniella chlamydospora showed no activity for any of these enzymes. All these enzyme activities were inhibited by the phenolic compounds in grapevine: p-coumaric acid, catechin, caffeic acid and tannins. The phenolic compounds also had a direct effect on fungal growth and sporulation. When 804 vines affected by Petri disease were treated with Brotomax (a product that stimulates synthesis of phenolic compounds), plants showed an increase of growth and a reduction of Petri disease symptoms. Any new shoot and root formed after Brotomax treatment did not show any sign of obstruction or tylose formation [La microscopia elettronica a scansione di fusti e radici di piante di vite affette dalla malattia di Petri ha dimostrato che l´ostruzione dei vasi xilematici e la riduzione del flusso della linfa grezza, due sintomi di questa malattia, erano determinate principalmente dalla formazione di tille nei vasi e, in minor misura, dall´accumulo di aggregati. Nello xilema sono state pure trovate ife fungine. Queste si propagavano attraverso lo xilema e invadevano altri vasi o cellule parenchimatiche adiacenti attraverso le punteggiature. L´analisi dell´attività della lignina perossidasi, della manganese perossidasi e della laccasi (enzimi coinvolti nella degradazione della lignina) in funghi diversi isolati da viti affette dalla malattia di Petri ha messo in evidenza che Phaeoacremonium aleophilum esprimeva bassa attività specifica per la manganese perossidasi ed elevata attività specifica per lignina perossidasi e laccasi, mentre Phaeomoniella chlamydospora non evidenziava attività per alcuno di questi enzimi. Tutte queste attività enzimatich