Abstract: Adverse effects of salinity (Tap water, 50, 100 and 200 mM NaCl) on some physiological
responses of Zea mays plant were studied. Salt stress induced the accumulation of the osmoprotectants,
total-soluble-N, amino-N and proline concurrently with an increase in protease activity. On the other
hand, protein-N and total-N contents were decreased as compared with those of the control. In
addition, the content of Na+ increased significantly under salinity stress, while K+, Ca+2 and Mg+2
contents were decreased, when compared with those of the control. Application of 100 ppm of
vitamins (nicotinamide or ascorbic acid) by grain soaking or shoot spraying, counteracted the adverse
effects of salinity and this accompanied by significant increases in total-nitrogen contents and amino-
N, and significant decreases in proline and protease activity. Also, treatment with vitamins by any of
the two methods resulted mostly in a decrease of Na+ accumulation and significant increases of K+,
Ca+2 and Mg+2 contents, when compared with those of the reference controls. Three prominent types
of modifications are observed in the protein patterns, some proteins were disappeared, certain of
other proteins were selectively increased and synthesis of a new set of protein was induced, some of
these responses were observed under vitamins and salinity, while others were induced by either
vitamin or salinity. |
