Histological Alterations Induced by Sodium Sulfate in the Vegetative Anatomy of

It may be inferred that plants that grow well in high salinity environments have specific structural adaptations to host altered physiological and biochemical mechanisms, while maintaining their reproductive capacity. However, knowledge of morphological and anatomical responses to salinity is still incomplete. The aim of the present work was to examine the effects of increasing concentrations of Na2SO4 (0-531 mmol L 1) on the structure modifications of the root (young and older zone), hypocotyl, young stem and leaflet from Prosopis strombulifera treated plants in relation to their controls. Seedlings were grown hydroponically in Hoagland's solution with addition of 19 mmol L 1 Na2SO4 every 48 h until final salt concentration of 190, 379 and 531 mmol L 1 were reached. Control plants were grown without salt. At 379 mmol L 1 Na2SO4 anatomical changes were marked and different to those induced by NaCl which were intensified at 531 mmol L 1 including greater number of cortical layers in primary root and earlier development of endodermis. Older root zones and hypocotyls showed reduced cambial activity. Young stems developed one to three layers of highly vacuolated cortical parenchyma. Leaflets were thin with dense chlorenchyma. Tannin content increased with salinization in the whole plant. The anatomical modifications described in the present work are produced to ensure the surviving of the plant under the stressing conditions imposed by the SO42 salt treatment and differed from those reported previously for NaCl. Plant anatomy is then other parameter strongly influenced by the nature of the ions in the salt solution.