The effect of various microelements on changes in the activity of certain enzymes in hydroponically cultivated barley during the first period of growth

The paper deals with the effect of the application of certain ions (Zn²⁺, B₄O₇ ^2- Mn²⁺, Cu²⁺, MoO₄ ^2-,) on the development of the activity displayed by amylase, urease, and glutamate-oxalacetate (GOT) in hydroponically cultivated barley during the first seven days of ontogenesis. The enzymes were studied separately in the overground and root parts of the plants. The following main conclusions can be drawn from the findings made: The amylase activity of the control plants in connection with their development diminished slightly in the overground part, while it was relatively constant in the roots. Due to the effect of certain elements tested, this activity increased pronouncedly (significant differences were confirmed in variants containing MoO₄ ^2-, Zn²⁺, and Co²⁺). The urease level in the overground part of the control plants remained low throughout the entire experimental period and was only little influenced by the individual microelements under study (with the exception of B⁴O₇ ^2-). On the other hand, the urease activity in the root system increased markedly, the B₄O₇ ^2- ions exhibiting a significantly stimulating effect. The activity of glutamate-oxalacetate transaminase (GOT) in the overground part of the control plants increased only slightly in the course of the initial development, while in the root system it grew relatively more pronouncedly. In the overground part of the plants all the microelements administered displayed a significantly depressive effect on the development of this enzyme activity; in the roots, the inhibitory action was maintained only in the last experimental period in variants with Zn²⁺ ions.