Slices from ripen table grapevine berries (healthy or infected by Botrytis cinerea Pers.) were briefly fixed in buffered Formaldehyde 1% or alternatively cryostabilized in cold ethylene glycol, thus avoiding any chemical fixation or solvent dehydration. Samples were then embedded in polar resin (Technovit 8100, Kulzer) and sectioned at 2.5 micron. Some histochemical techniques were tested, among them: Toluidine blue, Periodic Acid Schiff, Periodic Acid Silver Methenamine, DAPI for nuclei, Nile red for wax, Fe3+ salts for tannic substances. Moreover alkaline phosphatase (EC 3.1.3.1; Palk) and Polygalacturonase (EC 3.2.1.15; PG) activities were revealed using 5-Bromo-4-chloro-3-indolyl phosphate/Nitro BT (Sigma FAST BCIP/NBT) substrate for Palk and a new tetrazolium salt reduction method for PG. Enzymes activity was clearly detectable in the tissues of the infected berries, due to the penetration of B. c. iphae, always strongly positive. Both histological processing techniques allowed the localization and study of Palk, while PG activity was more evident in the cryostabilized samples. In healthy berries Palk was not detectable and PG was detectable only in the first cellular layers of the pericarp of cryostabilized samples.
Morphological and histochemical study of grape berry, fixed or cryostabilized.
Vallania R
2003
Abstract
Slices from ripen table grapevine berries (healthy or infected by Botrytis cinerea Pers.) were briefly fixed in buffered Formaldehyde 1% or alternatively cryostabilized in cold ethylene glycol, thus avoiding any chemical fixation or solvent dehydration. Samples were then embedded in polar resin (Technovit 8100, Kulzer) and sectioned at 2.5 micron. Some histochemical techniques were tested, among them: Toluidine blue, Periodic Acid Schiff, Periodic Acid Silver Methenamine, DAPI for nuclei, Nile red for wax, Fe3+ salts for tannic substances. Moreover alkaline phosphatase (EC 3.1.3.1; Palk) and Polygalacturonase (EC 3.2.1.15; PG) activities were revealed using 5-Bromo-4-chloro-3-indolyl phosphate/Nitro BT (Sigma FAST BCIP/NBT) substrate for Palk and a new tetrazolium salt reduction method for PG. Enzymes activity was clearly detectable in the tissues of the infected berries, due to the penetration of B. c. iphae, always strongly positive. Both histological processing techniques allowed the localization and study of Palk, while PG activity was more evident in the cryostabilized samples. In healthy berries Palk was not detectable and PG was detectable only in the first cellular layers of the pericarp of cryostabilized samples.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
