EFFECT OF NACL STRESS ON ION RETRANSLOCATION IN BARLEY

Barley plants (Hordeum vulgare L. cv. Union) were brought under a 1 % NaCl stress for 10 weeks. The effects on growth and ion distribution were followed on the whole plant level as well as on the level of the individual plant part (leaves, stem, ear). It was found that net K+ retranslocation was common in both control and salt treatment, so that there was no specific Na+ dependency for this K+ retranslocation. Even at a high nutritional strength, K+ retranslocation took place in both control and salt treatments, thereby indicating that the retranslocation was not induced by a K+ deficiency. A net Na+ ands Cl- retranslocation was observed for the salt treatment, but took place at a time when net K + export was almost complete. At a higher nutrient strenght the net retranslocation of Na+ and Cl- was limited to the older leaves. This type of selectivity in net retranslocation between K+ and Na+ is discussed as well as the role of the accompanying chloride. © 1990, Gustav Fischer Verlag, Stuttgart. All rights reserved.