Na + Distribution and Secretion Characters from Tamarix Hispida under Salt Stress

Abstract

Taking Tamarix hispida as test materials, a group of different concentrations of NaCl were then added to the pots and the salinity was maintained at5, 10, 15 and 20g/L. Na+ content of different samples were analyzed by ICP-AES. This paper studied Na+ distribution in various organs and secretion characters from Tamarix hispida under the stress of different salt concentration, discuss the selective absorption and Na+ transport mechanisms. The result show that Na+ content of Tamarix hispida were increasing prominently with increased salinity, the order of Na+ accumulation on Tamarix hispida is leaf>root>stem, leaf is the main part of Na+ accumulation and secretion. The secretion of Na+ is also enhanced with the increase of salt concentration. The excreting rate of salt gland was higher in the morning than that in the afternoon and higher in daytime than that at night. Because salt secretion has a high positive correlation with atmospheric humidity, at the same time it has a higher negative correlation with atmospheric temperature. Such high selectivity of salt gland secreting salt is the self-adjustment mechanism of Tamarix hispida to adapt to the habitat, maintaining the proper salt and nutrient contents.Keywordssalt stressTamarix hispidaNa + secretion