Mineral content, in shoots and roots of maize and soybean seedlings as affected by nacl and their relation to changes in chlorophylls and catalase activity

ABSTRACT

A water culture experiment was carried out to study the effect of NaCl stress on the uptake of some mineral elements, in the shoots as well as roots of maize and soybean seedlings. In addition chlorophylls content and catalase activity in the third fully mature leaf stage were studied. Salt stress was imposed on six day-old plants as [0.00-75-100 mM NaCl] grown in balanced standard nutrient solution. Shoot and root dry weight was reduced, while shoot-root ratio was significantly increased. The concentrations as well as the content of minerals differed in the three treatments. The content of K and Mg decreased in the shoots and roots showing the lowest value at 100 mM NaCl, in contrast Ca content increased with increasing NaCl level. Sodium increased much more in the shoots than in the roots. Content of Fe, Mn, and Cu were depressed with increment of NaCl level. Roots accumulated much more micro-nutrients than shoots. All levels of NaCl increased Chl. [a], for both plants, and caused a decrease in Chl [a+b] in maize and significant increase for soybean at 75 mM NaCl. Catalase activity showed significant increase at 100 mM for soybean. Furthermore the present study suggests that the changes in chlorophylls content and catalase activity may be used as a tool to compare between maize and soybean plants responses under NaCl stress