PHYSIOLOGICAL-RESPONSES OF SUSPENSION-CULTURES OF CATHARANTHUS-ROSEUS TO ALUMINUM - CHANGES IN POLYAMINES AND INORGANIC-IONS

The effects of aluminum (Al) treatment on polyamines were studied using suspension cultures of Madagascar periwinkle [Catharanthus roseus (L.) G. Don]. The addition of Al (0.2, 0.5, 1.0 mM) to the suspension cultures caused a significant increase in putrescine within 24h only in freshly transferred cells. By contrast, Al treatment reduced putrescine content at all other times (days 2-7). Further analysis showed that the largest increase in putrescine occurred at 6 h when Al was added at the time of transfer of cells to fresh medium. If Al treatment was delayed to as little as 3 h after transfer to fresh medium, the cellular level of putrescine decreased. While spermidine remained unchanged, spermine was significantly higher in the presence of Al in all cases. The inhibitory effect of Al on DNA synthesis also depended upon the time of its addition. Cellular Ca, Mg, and Mn decreased in response to Al given at the time of transfer to fresh media while Fe increased, and Na, K and P remained unchanged. The results indicate a critical physiological change in the response of cells to Al within a short time (about 3 h) after transfer to fresh medium.