. Adaptation of sunflower tissues to high NaCl levels. Changes in polyamines, proline and ethylene

ALVAREZ I, TOMARO ML AND BENAVIDES MP

Punta del Este, Uruguay

Congreso; . XI Reunión Latinoamericana de Fisiología Vegetal. XXIV Reunión Argentina de Fisiología Vegetal. I Congreso Uruguayo de Fisiología Vegetal; 2002

SAFV

Responses of sunflower tissues to NaCl stress were studied in control (C), salt-stressed (S and S2) and salt-adapted (T) calluses in terms of proline, polyamines and ethylene status along one period of 21 days. Proline concentration was 27 times higher in salt-adapted calluses compared to C calluses at time 0. After 21 days in culture, proline content in S2 calluses was more than 3 times higher than that of S and T calluses and largely more elevated (125 times) that proline content in C calluses. Putrescine (Put) was the most abundant polyamine in C calluses at time 0, while spermidine (Spd) was the main polyamine in salt tolerant (T) calluses. In control calluses, the highest level of total polyamines and the lowest of ethylene was found by day 21, while S2 and T calluses synthesized the highest ethylene level and the lower polyamines level of all the period. The pattern of the three main polyamines remained almost unaltered in S2 calluses along the time. It seems that in salt-adapted calluses ethylene was related to stress tolerance and in salt sensitive tissues (S calluses), ethylene formation occurred as senescence began. The present data suggest a close relationship between proline, polyamines, ethylene and salt-stress tolerance in sunflower dedifferentiated tissues.