Evaluation of changes in the element content and biomass of invaded with Meloidogyne arenaria Tiny Tim tomato plants under NH4VO3 treatment.

The parasite-host system Meloidogyne arenaria--Tiny Tim tomato plants has been studied in order to investigate the influence of the process of invasion on the chemical composition and biomass of plants. The concentrations of seven chemical elements Cu, Zn, Mg, K, Na, Mn and Fe have been determined using AAS in controls and invaded plants, and their changes have been evaluated under treatment with NH4VO3 in three different concentrations 0.01, 0.1 and 0.13 mg/100 ml H2O. The process of treatment with NH4VO3 disbalances significantly the trace element content of plants. The lowest concentration (0.01 mg NH4VO3) causes bigger changes in the concentrations of Mn, Fe and Na in non-invaded plants. The highest concentration (0.13 mg NH4VO3) balances the content of the elements back to their levels in the control plants for the elements Zn, Fe and Na. The pure effect of the process of invasion with Meloidogyne arenaria on the biomass (leaves, stems, roots and total biomass) of Tiny Tim plants is expressed in a significant increasing, mainly due to the development of the parasites. After treatment with different concentrations of NH4VO3 the decreasing in the biomass of leaves, stems and roots is observed which reflects on the total biomass of plants. The concentration of NH4VO3 eliminates the unfavourable changes not only in the chemical content of plants but also in their biomass. It could be taken into consideration as an alternative method used instead of treatment with nematocides.

[Light activation of the enzyme ribulose diphosphate carboxylase]. / Aktivirovanie svetom fermenta ribulozodifosfatkarboksilazy.

Some activation mechanisms of RuDP-carboxylase under illumination are considered. It is assumed on the grounds of experimental data that under illumination thylacoid membranes pass from one phase (I) to another (II). Kinetics of this transition is taken as similar to that of surface phase transition of the first kind. It is assumed that the number of enzyme molecules passing from the inactive to active state is proportional to the area of thylacoid membranes in the II phase (as the time function). A change in the stroma determined by the kinetics of transition of thylocoid membranes in the transition process leads to a change of the mean time between two successive catalytic acts of the enzyme activated molecules. The obtained kinetic curve of RuDP-carboxylating reaction in the transition process under illumination coincides with the curve obtained in [1] by expanding the experimental curves of the values of labels 14C, 32P of 3PGA to constituents.

[Kinetics of triphosphoglyceric acid formation in Chlorella pyrenoidosa (in vivo) during alternation of light and darkness]. / Kinetika obrazovaniiaa trifosfoglitserinovoi kisloty v Chlorella pyrenoidosa (in vivo) pri smene svetogovo i temnovogo rezhimov.

On the basis of specific features of carbon reduction cycle in photosynthesis (Kalvin cycle or reduction pentosophosphate cycle) and other processes, in which triphosphoryglyceric acid (3PGA) is an intermediate product, and taking into account the available data concerning the reaction of 3PGA pool of Ch. pyrenoidosa (in vivo) to light-dark disturbances approximate kinetic curves of the value of ribulosodiphosphate (RuDP)--carboxylating reaction product and of other 3PGA accumulations in the chloroplast strom aunder light-dark disturbances. Proceeding from the pecularities of these curves a hypothesis is advanced to the effect of some connection mechanisms of photosynthetic and glycolytic processes of 3PGA production.