Developmental processes, polyamine composition and content of fruiting cuttings of Vitis vinifera L.:: Responses to nitrogen deficiency

Fruiting cuttings of cv. Cabernet Sauvignon exposed to nitrogen (N) deficiency showed alterations of the N and phosphorus content, the number of berries per plant and berry characteristics at maturity. Conjugated and bound polyamines changed in various tissues at different and critical stages of development and responded strongly to N deficiency. At anthesis the conjugated and bound spermidine content in flowers and the N supply were closely and inversely correlated, while conjugated and bound forms of putrescine responded in the opposite way. However, in these organs N deficiency led to a high content of bound spermidine and a marked decrease of conjugated putrescine. At fruit set, N deficiency was associated with a high content of bound diaminopropane in berries. In ripe berries free putrescine and the N supply were inversely correlated.