Effects of eutypiosis on free and conjugated polyamines content in internodes of grapevine (Vitis vinifera L. cv. Cabernet sauvignon) during their active phase of growth

Development of polyamines levels [Putrescine (Put), Spermidine (Spd), and Spermine (Spm)] was investigated in internodes of grapevine infected by eutypiosis fungus, Eutypa lata. The study was performed using (1) internodes from healthy vines, (2) apparently healthy internodes from vines with one arm symptomless and one diseased arm and (3) diseases internodes. Free polyamines (PAs: hydrochloric acid soluble fraction), conjugated polyamines (PAs-fpm: PAs covalently linked to molecules with low molecular weight like hydroxycinnamic acids) and bound polyamines (PAs-mm: covalently linked to macromolecules) were analysed in Vitis vinifera L. cv. Cabernet sauvignon, which is sensitive to eutypiosis. The internodes stunting induced by eutypiosis was accompanied by a decrease of free Put and free Spm contents between flower buds separated and fruit set stages. The same results were observed for PAs-mm but more slightly than free PAs. The Put-fpm and Spd-fpm levels increased in the apparently healthy internodes and decreased in diseased organs by Eutypa lata effect. The relationship between free PAs contents in the diseased internodes and their growth reduction, as well the involvement of PAs-fpm on the grapevine response to Eutypa lata infection are discussed.