Effect of foliar treatment with boron and zinc on physiological responses of cow pea [vigna sinensis Cv. cream 7]: I Growth parameters, auxins, growth inhibitor contents, yield components, mineral composition of the harvested seeds and their protein pattern

ABSTRACT

In the present investigation Vigna sinensis plants cv. Cream 7 were sprayed with 10, 50 and 250 mgL[-1] of boron or zinc. The effect of the two elements on growth, endogenous auxins and growth inhibitor levels of shoots and roots and activities of certain related enzymes, mineral composition of the harvested seeds and their protein pattern were investigated too. The results revealed that the low concentration of boron or zinc caused high significant increases in most of the growth parameters and yield components concomitantly with increases in auxin contents, catalase activity and reductions in growth inhibitor level and activities of IAA-oxidase and peroxidase while the highest concentration induced a reverse pattern. The phosphorus, potassium, sodium and calcium, iron, manganese, zinc, copper and boron contents were increased in the harvested seeds when Vigna sinensis plants were sprayed with boron or zinc. The scanning profiles for the banding pattern of each protein sample extracted from Vigna sinensis seeds harvested from plants previously sprayed with boron or zinc and extracted in Tris-Hcl buffer [pH 8.0] or Tris-Glycine buffer [pH 8.2] were studied. All concentrations applied of zinc and the highest concentration of boron induced de novo synthesis of a polypeptide with a molecular mass of 59 KD