Sodium fluoride induced metabolic changes in jack pine seedlings. II. Effect on growth, acid phosphatase, cytokinins, and pools of soluble proteins, amino acids, and organic acids

Abstract

The effects of sodium fluoride on growth, cytokinin activity, acid phosphatase activity, and levels of soluble proteins, free amino acids, and organic acids in jack pine (Pinusbanksiana Lamb.) seedlings were studied. Fresh and dry weights of seedlings were already reduced after 24 h of sodium fluoride treatment. No significant change in cytokinin levels was found in seedlings treated with 1 mM sodium fluoride. A higher (10 mM) concentration resulted in some decrease in cytokinin activity, which was insufficient, however, to account for the complete growth inhibition of seedlings. Marked reduction in cytokinin(s) with similar chromatographic behaviour to that of isopentenyl adenine and isopentenyl adenosine was observed in plants subjected to the 10-mM sodium fluoride treatment. Activity of acid phosphatase extracted from seedlings was drastically reduced by sodium fluoride invitro. When the enzyme was isolated from fluoride-treated plants, its activity was also lower but the inhibition was less pronounced. Levels of both organic and amino acids were affected by fluoride treatments. Depending on the level of fluoride treatment, the amount of soluble proteins decreased or showed no significant change. The implications of the observed changes are discussed.