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 abscisk acid (ABA)‐treated barley leaves (Hordeum vulgare L. cv. Georgie) accumulating pro‐line. 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 tacking 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.