EFFECT OF COMPLEXONS, DERIVATIVES OF SUCCINIC ACID, ON THE FORMATION OF CAROTENOIDS IN GREEN PLANTS

На основании обобщения результатов многолетних лабораторных и полевых опытов обнаружена зависимость уровня содержания жёлтых фотосинтетических пигментов в растениях от внекорневой обработки растворами комплексонов. Комплексоны, производные янтарной кислоты (иминодиянтарная кислота, этилендиаминдиянтарная кислота, диаминоциклогександиянтарная кислота) способствуют накоплению каротиноидов в зелёных растениях, а этилендиаминтетрауксусная кислота существенно не влияет на их содержание. Based on the generalization of the results of many years of laboratory and field experiments, the dependence of the content of yellow photosynthetic pigments in plants on foliar treatment with solutions of complexones was found. Complexones, derivatives of succinic acid (iminodisuccinic acid, ethylenediaminedisuccinic acid, diaminocyclohexanedisuccinic acid) contribute to the accumulation of carotenoids in green plants, and ethylenediaminetetraacetic acid does not significantly affect their content.

Chelation-Assisted Ion-Exchange Leaching of Rare Earths from Clay Minerals

The effect of biodegradable chelating agents on the recovery of rare earth elements (REE) from clay minerals via ion-exchange leaching was investigated, with the aim of proposing a cost-effective, enhanced procedure that is environmentally benign and allows high REE recovery while reducing/eliminating ammonium sulfate usage. A processing route employing a lixiviant system consisting of simulated sea water (equivalent to about 0.5 mol/L NaCl) in conjunction with chelating agents was also explored, in order to offer a process alternative for situations with restricted access to fresh water (either due to remote location or to lower the operating costs). Screening criteria for the selection of chelating agents were established and experiments were conducted to assess the efficiency of selected reagents in terms of REE recovery. The results were compared to extraction levels obtained during conventional ion-exchange leaching procedures with ammonium sulfate and simulated sea water only. It was found that stoichiometric addition of N,N′-ethylenediaminedisuccinic acid (EDDS) and nitrilotriacetic acid-trisodium form (NTA-Na3) resulted in 10–20% increased REE extraction when compared to lixiviant only, while achieving moderate Al co-desorption and maintaining neutral pH values in the final solution.

The Study of Degradation of Complexones, Derivatives of Succinic Acid, and their Boron-Containing Complexes Under the Influence of Microbiological Preparations

The results of the study of the possibility of degradation of complexones, derivatives of succinic acid (CDSA), iminodisuccinic acid (IDSA), ethylenediaminedisuccinic acid (EDCSA), trans-1, 2-diaminocyclohexanedisuccinic acid (DCHDSA) and complexones taken for comparison, derivatives of iminodiacetic acid (IDSA) and ethylenediaminetetraacetic acid (EDTAA) under the influence of microbiological preparations “Baikal EM-1” and “Rhizoplane L”, as well as borate complexes of CDSA: B-IDSA, B-EDCSA and B-DCHDSA under the influence of the preparation Rhizoplane L at a temperature 22±1oC in an aqueous medium. It was found that within 4.5 months of the compounds taken for research under the action of Rhizoplane L preparation, B-IDSA was degraded to greatest extent (by 88%), and under the action of Baikal EM-1 preparation more than other degraded CDSA (by 86%) and EDTAA. Simultaneous destruction of DCHDSA and B-DCHDSA when exposed to the preparation taken for the experiment was not noted.

Levels of induced free proline in chelated and unchelated hydroponically grown lettuce (Lactuca sativa L.)

It is well described that under stress conditions many plant species accumulates proline as adaptive response to adverse conditions. In this study, eight weeks old Lactuca sativa L. seedlings were transplanted in nutrient solution containing various doses (0.000, 0.0025, 0.005, 0.0075, and 0.025mg/L) of Pb2+ and Cd2+ and constant concentration of EDDS (0.0025M). The effects of these treatments of Pb2+, Cd2+, combination of Pb2+ + Cd2+and with or without EDDS (Ethylene diamine disuccinate) were compared based on the level of stress induced to the seedlings. Free proline contents induced due to stress by uptake of Pb2+and Cd2+ were investigated in both unchelated and chelated treatment. The results obtained showed that the effect of increasing concentration of Pb2+ in hydroponic solution leads to decrease in the level of stress induced to the seedlings by EDDS while the lower the Cd2+ concentration in the hydroponic solution the more the level of stress induced by EDDS to the plant. The highest level of stress caused to the seedlings by unchelated and chelated Pb2+ solution are 68.294±5.642; 72.681±14.740 µmolg-1 respectively while that of Cd2+ are 28.962±8.703; 48.263±2.455 µmolg-1 respectively. From this, it is evident that Pb2+induced more stress to the plants than Cd2+ in the presence and absence of EDDS (p<0.05). Keywords: Proline, Ethylenediaminedisuccinic Acid (EDDS), Lead, Cadmium, Lettuce.