[Influence of NaCl- and abscisic acid treatment on protein metabolism and some further enzymes of amino acid metabolism in seedlings of Pennisetum typhoides]

Abstract

The effects of sodium chloride (NaCl) and abscisic acid (ABA) on protein synthesis, protein hydrolysis, glutamine synthetase, Δ-pyrroline-5-carboxylate reductase and amino acid composition have been studied in aerial parts of Pennisetum typhoides (Stapf et Hubbard) seedlings. Whereas protein synthesis is inhibited by NaCl and ABA, the activity or the synthesis of leucine-arylamidase, glutamine synthetase and Δ-pyrroline-5-carboxylate reductase is promoted by both the substances. The results of the amino acid analysis showed that in the presence of NaCl and ABA the amounts of alanine, aspartate and ammonia decreased, while the concentrations of glutamate, and especially that of proline increased greatly. The possible significance of the results in explaining the proline accumulation under stress conditions and ABA-treatment is discussed.