Histological study of the responses of two Vitis vinifera cultivars (resistant and susceptible) to Plasmopara viticola infections

• Published in: Plant physiology and biochemistry Vol. 41; no. 9; pp. 846 - 853
• Main Authors: Gindro, Katia, Pezet, Roger, Viret, Olivier
• Format: Journal Article
• Language: English
• Published: Paris Elsevier Masson SAS 01.09.2003; Elsevier
• Subjects: ANATOMIE VÉGÉTALE; ANATOMÍA DE LA PLANTA; Biological and medical sciences; Callose; DEFENCE MECHANISMS; Defense reactions; DISEASE RESISTANCE; ESTOMA; Fundamental and applied biological sciences. Psychology; Fungal plant pathogens; HISTOPATHOLOGIE; HISTOPATHOLOGY; HISTOPATOLOGÍA; MECANISMOS DE DEFENSA; MÉCANISME DE DÉFENSE; Pathology, epidemiology, host-fungus relationships. Damages, economic importance; Phytopathology. Animal pests. Plant and forest protection; PLANT ANATOMY; PLASMOPARA VITICOLA; RESISTENCIA A LA ENFERMEDAD; RÉSISTANCE AUX MALADIES; STOMATA; STOMATE; VITIS VINIFERA; VITIS VINÍFERA; Plasmopara viticola; Defense reactions; Stomata; Vitis vinifera; Callose; Genetic variability; Plant pathogen; Phycomycetes; Host agent relation; Necrosis; Fungi; Sensitivity resistance; Fruit crop; Vitidaceae; Dicotyledones; Angiospermae; Spermatophyta; Deposition; Thallophyta
• ISSN: 0981-9428; 1873-2690
• DOI: 10.1016/S0981-9428(03)00124-4

Leaves of Vitis vinifera L. cvs. Chasselas (susceptible) and Solaris (resistant) were inoculated with Plasmopara viticola. Samples were then examined by scanning electron microscopy, light and epifluorescence microscopy. On the resistant cv. Solaris, stomatal deposits, identified as callose, were visible around the germinating zoospores 7 h after inoculation. Twenty-four hours after inoculation, infected stomata exhibited secretions that enveloped the zoospores. At this time, infected stomata were surrounded by necrotic tissues. At 120 h after inoculation, undefined material was deposited on the cuticle in the necrotic areas. Stomata in the vicinity of the infection sites contained callose deposits in and around the stomatal openings, but no necrotic zones were observed. On the sensitive cv. Chasselas neither secretion nor callose deposits were observed. Sporangiophores emerged about 96 h after inoculation and were fully developed 24 h later. Sporulation through small stomata-like apertures present all along the primary vein was also observed on the upper leaf surface. The role of stomatal callose deposits in the defense reactions of the Solaris grapevine cultivar against P. viticola is discussed.