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Involvement of polyamines in the control of fruitlet physiological abscission in grapevine ( Vitis vinifera )
Author(s) -
Aziz Aziz,
Brun Oliver,
Audran JeanClaude
Publication year - 2001
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1034/j.1399-3054.2001.1130107.x
Subject(s) - abscission , spermidine , putrescine , inflorescence , spermine , ornithine decarboxylase , veraison , biology , arginine decarboxylase , anthesis , botany , polyamine , cultivar , vitis vinifera , horticulture , biochemistry , enzyme
The potential contribution of polyamines (PAs) in the regulation of physiologically induced fruitlet abscission was investigated in cuttings from two cultivars of Vitis vinifera L., Pinot noir (PN) and Merlot (MRT). Abscission was higher in MRT than in PN and was preceded by a decrease in free PA levels. This decline was more pronounced in inflorescences than in leaves of the sensitive cultivar. Soluble conjugated PA showed an opposite trend in both cultivars. This suggests a cause‐effect relationship between free and/or conjugated PA levels in floral organs and susceptibility to abscission. Spermidine (Spd), but not putrescine (Put) or diaminopropane, supplied at 0.5–1 m M to the nutritive medium prior to the anthesis, increased free and conjugated PA levels in the inflorescences and markedly inhibited abscission. α ‐Difluoromethylarginine, an inhibitor of arginine decarboxylase, but not α ‐difluoromethylornithine, an inhibitor of ornithine decarboxylase, lowered PA levels and increased abscission. Treatment with cyclohexylamine or β ‐hydroxyethylhydrazine as potent inhibitors of Spd synthase and PA oxidases, respectively, reduced the Spd and/or spermine levels and enhanced free Put in the inflorescences, inducing an increased abscission of floral organs shortly after anthesis. These data suggest that PAs, particularly Spd, could be involved in the regulation of grapevine fruitlet physiological abscission.