PLANT BIOSYSTEMS, cilt.141, sa.1, ss.31-39, 2007 (SCI-Expanded)
Changes in the content and form of polyamines (PAs) were investigated in shoots of salt-tolerant (Coban) and salt-sensitive (Sanbro) cultivars of sunflower (Helianthus annuus L.) plants grown for 15 or 25 days under salinity stress (50, 100 and 150 mM NaCl). The salt sensitivity of the sunflower plants was associated with the highest accumulation of total PAs in the shoot tissues of the salt-sensitive cultivar under saline conditions. The amounts of free and total spermine increased in shoot tissues of sunflower plants subjected to salt stress, while the levels of other PAs decreased or showed no significant changes. This suggests that spermine plays a potential role in overcoming the adverse effects of salinity stress. The tissue content of other compounds, such as proline, and ions (Na+, K+, Cl-, K+/Na+) also changed depending on salt concentration and cultivar.