Jan Bialczyk

Chemical composition of xylem sap of tomato grown on bicarbonate containing medium

Abstract Incorporation of bicarbonate (HCO3 ‐) by the roots of tomato seedlings resulted in an increase in biomass production and changed the chemical composition of xylem sap. In the xylem sap of seedlings grown on a medium enriched with HCO3 ‐ (5.68 mM dm‐3, series II) compared with the control (series I) the element content increased by about 27% and 33% for cations and anions, respectively. Potassium was the major cation in the xylem sap and constituted 69% of the total concentration of all the inorganic cations determined. Calcium attained 19% of this amount. The anionic load in the xylem sap was chiefly nitrate, constituting about 90% of the content of all the inorganic anions. The exudate was analysed for seven organic acids. In general, malic (MA), maleic, and citric (CA) occurred in xylem exudate at greater concentrations, constituting about 95% of the total content of organic acids. Cultivation of seedlings on the medium enriched with HCOJ brought about an increased content of organic acids, exc...

Absorption of HCO3- by roots and its effect on carbon metabolism of tomato

Abstract Six‐week old seedlings of tomato [Lycopersicon esculentum) were placed in growth chambers, hypocotyl and the root system (in the lower part of the chamber) being precisely separated from the stem (the upper part of the chamber). The composition of the medium was modified by enriching it with KHCO3 (converted to the value of about 0.1% CO2 concentration) or additionally with 14C. The total radioactivity associated with roots, shoots, and leaves after 72 h chase period was determined. About 61% of the total radioactivity were found in root and 39% in shoots and leaves. Differences in the concentration of HCOâ in the medium significantly modified the concentration of malic acid (MA) in the tissues. An increase in KHCO3 concentration in the medium to the level equivalent to about 0.1% CO2 raised the level of MA by about 854%, 150%, and 134% in root, shoot, and leaf, respectively, in relation to the control (without KHCO3). The occurrence of phosphoenolpyruvate carboxylase (E.C. 4.1.1.31) was found in...

Carbohydrate and free amino acid contents in tomato plants grown in media with bicarbonate and nitrate or ammonium

Tomato plants were cultivated (from 2 to 23 days after germination) in media with NO3−, NH4+, or a mixture of both forms in different proportions used as the N source given with or without 5 mol dm−3 HCO3−. The accumulation of soluble sugars (reducing sugars and sucrose) and free amino acids was higher in the roots and leaves of NH4+-fed plants than in NO3−-fed plants. Starch accumulation in NH4+-fed plants was higher in leaves (about 28%) and lower in roots (about 37%) in comparison with that of NO3−-fed plants. Plants cultivated in media containing a mixture of NO3−/NH4+ were characterized by a lower content of sugars and amino acids accumulation in comparison with that in plants fed with NO3− or NH4+. An elevated HCO3− concentration in the rhizosphere stimulated the accumulation of soluble sugars and free amino acids in all the experimental variants. There were only small differences in the starch content.

Fruiting of tomato cultivated on medium enriched with bicarbonate

Abstract The incorporation of bicarbonate (HCO3 ‐) by roots and the transport of its products to plant tops significantly affected the yield of tomato. Fresh weight of fruit exceeded the control by 32.6% on average. The result was parallel associated with fruit ripening which began by 10 days earlier and also with the final phase of this process shortened by five days. Changes were determined in the content of individual sugars [glucose (G), fructose (F), and sucrose] and organic acids [malic (MA) and citric (CA)] in the outer wall of pericarp and in the locular tissue. As compared with the control, in the series with HCO3 ‐ (series II) the content of G+F increased by about 34% and 46% in the wall and by 23% and 30% in the locular tissue of mature green and red stage, respectively. Distribution of G and F in the wall and locule was 3:1 in the control at the mature green phase and fell to 2.2:1 as the fruit ripened. In series II this ratio was similar for the two kinds of tissue, being 3.3:1 and 2.2:1. Mor...

Early Vegetative Growth of Tomato Plants in Media Containing Nitrogen Source as Nitrate, Ammonium, or Various Nitrate–Ammonium Mixtures with Bicarbonate Addition

Abstract The effect of various concentrations applied in media with , , or various mixtures of both on the accumulation of biomass and early vegetative growth of tomato (Lycopersicon esculentum Mill.) plants was tested in experiments carried out in hydroponics. The optimum concentration was 5 mM and was similar in all the combinations of the N source applied at 3 mM concentration. The average biomass of -grown plants without reached only 50% of the value for the plants if was used as the N source. With respect to the growth without , the biomass increased by about 160% or 130% with or used as the N source, respectively. The biomass of -grown plants in media with reached only about 42% of the value obtained by plants cultivated in media with and . Similar relations were observed in the size of leaf blades. A simultaneous addition of to the medium containing ameliorated the toxic effects of this compound. The optimum ratio of for the growth of plants was ≤ 1. The use of such proportions of nitrogen (N) forms in the medium stimulated the accumulation of biomass to about 115% of the mass attained by -grown plants. The addition of to the medium containing the N source in the two forms at an optimum ratio stimulated an increase in the biomass of plants by about 180% with respect to plants without . Certain growth parameters calculated, i.e., shoot to root ratio, specific leaf area, and relative growth rate confirm the ameliorating effect of if added to media containing and the stimulating effect of on the biomass production of different organs of the plants.

Determination of some cyanopeptides synthesized by Woronichinia naegeliana (Chroococcales, Cyanophyceae)

Nineteen compounds isolated from field samples of cyanobacteria Woronichinia naegeliana (Unger) Elenkin were identified. They fell into four classes of peptides: cyanopeptolins (cyanopeptolin B, cyanopeptolin C, cyanopeptolin D, cyanopeptolin 880, micropeptin 88D, micropeptin 478‐B, micropeptin SD999, micropeptin T2, planktopeptin BL1061), microginins (microginin 478, microginin 757, microginin 51A, microginin 91E, microginin FR3, microginin FR4), anabaenopeptins (oscillamide B) and possibly microcystins (trace amounts of microcystin‐LR) showing respectively fragment patterns in their electrospray ion source‐MS spectra. The molecular masses of the determined peptides range from 700 to 1100 Da. These results confirm the remarkable ability of cyanobacteria to synthesize a wide array of peptides.

The protective action of tannins against glasshouse whitefly in tomato seedlings

The synthesis and accumulation of tannins on tomato seedlings are regulated by environmental factors. The variation in the content of tannins was sufficiently important to bring about the occurrence of significant differences in the numbers of glasshouse whitefly on the seedlings. During a 2-week experiment, the treatments included mechanical wounding (20 prickings per cm 2 ), spraying with kinetin solutions of 10 -4 mol/dm 3 , plant growth regulators, and the atmosphere enrichment to 680 μmol CO 2 /mol air, the content of tannins being increased by c. 40, 70, 10-45 and 25 % above the values obtained in the control. These results were correlated with a decrease in the numbers of insects occurring on the seedlings by c. 35, 45, 8-29 and 18 %, respectively. Contrary to the above results the spraying with solutions of abscisic acid, gibberellic acid, and the incubation of plants in an atmosphere containing 170 μmol CO 2 /mol air, reduced the content of tannins by c. 69, 22 and 25 %, respectively. This was reflected in the respective increases by c. 70, 40 and 35% in the numbers of insects occurring on the seedlings. The obtained results suggest that tannins seem to have a dosage-dependent effect on glasshouse whitefly. Decreasing the host plant quality by increasing tannin content may act as an important selective agent limiting the losses brought about by glasshouse whitefly in tomato cultivation.

Phytoremediation of anatoxin-a by aquatic macrophyte Lemna trisulca L.

The neurotoxin anatoxin-a (ANTX-a), one of the most common cyanotoxin, poses a health risk to people and can be lethal to aquatic organisms. This paper presents results on its bioremediation by the aquatic macrophyte Lemna trisulca. We show that the plant is resistant to the harmful impact of toxin and is capable of removing ANTX-a from water. Some of the ANTX-a concentrations which were used in our experiments were much higher than those found in natural conditions. The exposition of L. trisulca to 2.5 μg ANTX-a/mL did not affect its biomass accumulation within 24 d. Significant decreases in biomass content by 21% and 30% were demonstrated in samples cultivated in media containing 12.5 μg ANTX-a/mL after 18 and 24 day of experiment, respectively. One gram of fresh weight (f.w.) of L. trisulca cultured for 14 d in the media containing 50 μg ANTX-a removed 95% of the initial toxin concentration; for media with 250 μg ANTX-a, 86% was removed. In tests of ANTX-a binding stability and degradation we transferred the macrophyte to fresh media without added toxin; within 14 d the content of accumulated ANTX-a in the macrophyte decreased by 76% (from initial 19.3 μg ANTX-a/gf.w.), 71% (from 37.3 μg ANTX-a/g f.w.) and 47% (from 63.7 μg ANTX-a/g f.w.). The quantity of ANTX-a released to media was minimal: from 3.5% to 5.1% of the initial bioaccumulated value. The data show that part of the ANTX-a was degraded. Mass spectra analyses did not indicate transformation of ANTX-a to already known forms. These findings suggest that L. trisulca has much potential as a phytoremediation agent for stabilization of aquatic environments.

Degradation of microcystin-LR by ozone in the presence of Fenton reagent

In this study the effectiveness and feasibility of the degradation of microcystin-LR (MC-LR) using a combined method ozone/Fenton reagent was investigated. The decomposition of the toxin was determined by the chromatographic technique. The effect of the Fenton reaction on the ozonation was observed at various concentrations of ozone at pH 3.0 and 6.8. A low concentration of ozone (0.01 mg/L) given simultaneously with Fenton reagent was more effective in MC-LR degradation than ozone or Fenton reagent treatment individually regardless of the pH. At higher concentrations of ozone the use together with Fenton reagent at pH 6.8 was less efficient in MC-LR degradation than treatment with ozone alone, whereas at pH 3.0 Fenton process turned out to be more effective. The mixture of ozone and hydrogen peroxide was more striking than using ozone with Fenton reagent regardless of the pH. The complete degradation of MC-LR was achieved using ozone alone at a concentration of 0.10 mg/L, whereas the same result using ozonation with Fenton reagent required a dose of ozone of 0.20 mg/L at pH 6.8. In acidic pH the total removal of MC-LR was achieved using ozone alone at a concentration of 0.20 mg/L and the same result was obtained for the combined method of ozone/Fenton reagent.

Fruit yield of tomato cultivated on media with bicarbonate and nitrate/ammonium as the nitrogen source

ABSTRACT This article presents the effects of nitrate/ammonium (NO3 −/NH4 +), applied at different proportions to the root media with or without 5 mmol bicarbonate (HCO3 −), on the yield and chemical composition of tomato fruit. Tomato plants were grown hydroponically (pH 6.9) in glasshouse conditions. The yield of fruit fresh matter from four clusters obtained from plants grown on the medium with NH4 + was about 25% lower than from the plants grown on the medium containing NO3 − as the nitrogen (N) source. Supplying NO3 −/NH4 + at a ratio of 4:1 increased the fruit yield by about 20% in comparison with the value recorded for NO3 −−plants. The enrichment of the medium with HCO3 − stimulated the bearing, while the result depended on the ratio of NO3 −/NH4 +. A combined treatment of HCO3 − with NO3 − or NH4 + in the medium increased yields by about 28% and 11%, respectively, in comparison to plants cultivated without HCO3 −. The application of NO3 −/NH4 + at ratios of 4:1 and 1:1 with HCO3 − increased the respective yields by about 16% and 10% in comparison with plants grown without HCO3 −. Modifications in the composition of the media affected the accumulation of organic solutions in the fruit. The NH4 + nutrition effected a 20% decrease in the accumulation of reducing sugars in the fruit in comparison to the fruit of plants grown in media with NO3 −. In the cultivation of plants in media with various NO3 −/NH4 + proportions the intermediate values of the reduced sugar concentrations were recorded in comparison with the values obtained for NO3 −−plants and NH4 +−plants. The enrichment of media with HCO3 − increased the concentration of sugars in fruit from about 28% (for NO3 −−plants) to about 10% (for NH4 +−plants). Malate and citrate are the main constituents of carboxylates in tomato fruit. The form of nitrogen applied to the medium did not significantly affect the concentration of carboxylates in fruit. Significant differences in carboxylate concentrations appeared in fruit grown on media enriched with HCO3 − ions. In comparison with the cultivation without HCO3 −, increases in the accumulation of carboxylates varied from about 22% to 30% depending on the form of the applied nitrogen. The concentration of amino acids in the fruit of plants grown with NH4 + exceeded that in NO3 −−plants by about 55%. In the plants grown on media of modified NO3 −/NH4 + proportions, the concentration of amino acids in fruits were positively correlated with the level of NH4 + in the medium. The enrichment of media with HCO3 − stimulated a further increase in amino acid concentration in fruit by about 9% in NO3 − plants and about 21% in NH4 + plants compared with the respective control (without HCO3 −).