ISSN:
1573-5087
Keywords:
anthocyanins
;
basic isoperoxidases
;
indole-3-acetic acid oxidase activity
;
suspension cell cultures
;
vacuoles
;
Vitis vinifera var. Gamay
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Abstract The study of the subcellular localization of the basic isoperoxidases in grapevines was carried out by using cells cultured in suspension as a model system. Results from subcellular fractionation, isoenzyme analysis, enzyme binding and cytochemical probes suggest that basic isoperoxidases are localized mainly in the vacuolar sap of the suspension cultured cells, probably in equilibrium with a pool of the same basic isoperoxidases bound to the internal face of tonoplast membranes through a Ca2+-saline bridge. This vacuolar location of basic isoperoxidases raised the question of their function, since indole-3-acetic acid (IAA) oxidase activity of these isoperoxidases is almost totally inhibited by vacuolar anthocyanins in the in vivo concentration range of these compounds. Thus, a central role is proposed for these isoenzymes in the H2O2-dependent oxidative phenol metabolism which occurs in grapevines, discarding therefore a possible role of these isoperoxidases in the control of IAA levels during the later stages of development of anthocyanin-rich grapes.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00024959
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