THE PROCESS OF ABSCISIC ACID-INDUCED PROLINE ACCUMULATION AND THE LEVELS OF POLYAMINES AND QUATERNARY AMMONIUM-COMPOUNDS IN HYDRATED BARLEY LEAVES

The contents of polyamines and quaternary ammonium compounds (QAC), substances involved in several kinds of stress phenomena, were tested in abscisic acid (ABA)-treated barley leaves (IIordeum vulgare I. cv. Georgic) accumulating proline. The characteristic parameters of the accumulation of proline induced by ABA [i.e. kinetics of accumulation, synergistic interaction hormone-K(Na)Cl, enhancing effect of Cl-, inhibiting effect of tetraethylammonium chloride (TEA), D-mannose and glucosamine] were lacking as far as polyamine and QAC content was concerned. Moreover: i) ABA slightly decreased the level of spermine and spermidine, slightly increased that of putrescine but did not influence the level of QAC; ii) the content of polyamines was reduced by KCl; iii) treatment with sorbitol increased the level of polyamines and prevented proline accumulation induced by ABA. These results indicate that there is no relationship between ABA-induced proline accumulation, polyamine level and QAC level; furthermore, accumulation of proline by ABA treatment is possible without increasing the levels of polyamines and QAC.