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Martin Bačkor - One of the best experts on this subject based on the ideXlab platform.
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changes of metal induced toxicity by h 2 o 2 no modulators in Scenedesmus Quadricauda chlorophyceae
Environmental Science and Pollution Research, 2013Co-Authors: Frantisek Stork, Martin Bačkor, Jozef Kovacik, Bořivoj Klejdus, Josef HedbavnyAbstract:Effect of nitric oxide donor (sodium nitroprusside, SNP, 500 μM) or hydrogen peroxide scavenger (dithiothreitol, DTT, 500 μM) on cadmium (Cd) or copper (Cu) uptake (150 μM solutions) and toxicity using Scenedesmus Quadricauda was studied. Combined treatments (Cd or Cu + DTT or SNP) usually ameliorated metal-induced toxicity at the level of pigments, proteins, and mineral nutrients in comparison with respective metal alone. Viability tests (MTT and TTC) showed the lowest values preferentially in Cu treatments, indicating higher toxicity in comparison with Cd. Cd showed low impact on amino acids while strong Cu-induced depletion was mitigated by DTT and SNP. Amount of ROS and NO showed the most pronounced responses in SNP variants being rather reciprocal than parallel and regulated ascorbate peroxidase activity. Blot gel analyses of hsp70 protein did not reveal extensive changes after given exposure period. Phenols were elevated by DTT alone while all Cu treatments revealed depletion. Total Cu content decreased while total Cd content increased in metal + SNP or metal + DTT. Subsequent experiment using lower Cd, SNP or DTT doses (10 and 100 μM) revealed concentration-dependent impact on Cd uptake. Overall, DTT was found to be more suitable for the amelioration of metal-induced toxicity.
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Influence of long-term exposure to copper on the lichen photobiont Trebouxia erici and the free-living algae Scenedesmus Quadricauda
Plant Growth Regulation, 2010Co-Authors: Juraj Piovár, Eliza Stavrou, Jana Kaduková, Tatiana Kimáková, Martin BačkorAbstract:In the present work, the long-term effect (14 days) of copper on the levels of intracellular and total copper accumulation, growth, assimilation pigment composition, chlorophyll a fluorescence, soluble protein content and oxidative status (production of hydrogen peroxide and superoxide) in two algal species (Scenedesmus Quadricauda and Trebouxia erici) was assessed. Scenedesmus Quadricauda is a free-living alga while Trebouxia erici is the photobiont of a lichen. The presence of copper negatively affected growth, assimilation pigments, chlorophyll a fluorescence, soluble protein content and oxidative status in both the algae. However, Scenedesmus was much more sensitive compared to Trebouxia.
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Comparison of the phytotoxic effects of usnic acid on cultures of free-living alga Scenedesmus Quadricauda and aposymbiotically grown lichen photobiont Trebouxia erici.
Journal of chemical ecology, 2010Co-Authors: Martin Bačkor, Katarína Klemová, Miriam Bačkorová, V. IvanovaAbstract:The phytotoxic effects of the lichen secondary metabolite—usnic acid on cultures of free living alga—Scenedesmus Quadricauda (UTEX 76) and aposymbiotically grown lichen photobiont Trebouxia erici (UTEX 911) were assessed. We found a relatively strong inhibition effect of usnic acid on the growth of alga Scenedesmus, accompanied by an increase of cell size, an alteration of assimilation pigment composition, followed by strong degradation of chlorophyll a, a decrease of chlorophyll a fluorescence, and an increase of reactive oxygen species in the cells. The content of soluble proteins remained a stable parameter. Phytotoxicity of usnic acid on cultures of Trebouxia photobiont was significantly lower. Usnic acid in lichens may act as an allochemical that controls the division of photobiont cells, thereby regulating the balance between the photobiont and mycobiont forming thallus. Higher tolerance to usnic acid in Trebouxia cultures may be an adaptation resulting from the long term co-evolution of these algae with fungi that produce secondary metabolites.
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effect of copper and salicylic acid on phenolic metabolites and free amino acids in Scenedesmus Quadricauda chlorophyceae
Plant Science, 2010Co-Authors: Jozef Kovacik, Bořivoj Klejdus, Josef Hedbavny, Martin BačkorAbstract:Species of the genus Scenedesmus are frequently used in studies focused on heavy metal toxicity and phenols represent important tool for stress protection. However, deeper knowledge about accumulation of phenolic metabolites in algae still absents. We therefore studied selected metabolic responses of widely distributed green algal species Scenedesmus Quadricauda to short-term (24 h) effect of copper (Cu), salicylic acid (SA) and their combined application (25 μM for both). Exposure to Cu led to decrease in chlorophylls while SA stimulated increase in chlorophylls. Soluble proteins and total soluble phenols were depressed by Cu treatment while SA had no effect and did not reverse influence of Cu in combined variant. Endogenous SA decreased in Cu + SA treatment and this depletion had no direct effect on the accumulation of the majority of detected phenolic acids, while individual amino acids seemed to be affected. Considerable accumulation of benzoic acids and their noticeable responses to SA may suggest involvement in protection against Cu toxicity since intracellular Cu remained unchanged by exposure to Cu + SA. These observations are discussed in the context of biosynthesis of phenols and possible signalling mechanisms are also suggested.
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Physiological Responses of Scenedesmus Quadricauda (Chlorophyceae) to UV‐A and UV‐C Light
Photochemistry and Photobiology, 2010Co-Authors: Jozef Kovacik, Bořivoj Klejdus, Martin BačkorAbstract:: Despite intensive research focused on the effects of UV-B, deeper metabolic responses to UV-A and UV-C are still scarce. Besides, especially microalgal species had to develop efficient protective features in comparison with tissue structure of vascular plants. We exposed axenic cultures of Scenedesmus Quadricauda (Chlorophyceae) to UV-A (366 nm) and UV-C (254 nm) light over 1 h. Both wavelengths stimulated increase in soluble proteins, superoxide radical and hydrogen peroxide, but had a nonsignificant effect on cell viability. Within 17 detected free amino acids, five (including proline) increased in response to UV-A while only aspartic acid and histidine increased in UV-C treatment. Total soluble phenols and flavonoids were influenced neither by UV-A nor by UV-C while selected flavonols (quercetin and kaempferol) decreased in UV-A and were not detected in UV-C treatment. Benzoic acid derivatives increased preferentially after UV-A illumination (vanillic acid and vanillin) while cinnamic derivatives (caffeic, chlorogenic and p-coumaric acids) decreased in both UV-A and UV-C. It is concluded that UV light stimulated oxidative stress while exposure time was not sufficient to stimulate larger changes in phenolic metabolites. Present findings in the context of available data and with emphasis on phenolics in algae are discussed.
Jozef Kovacik - One of the best experts on this subject based on the ideXlab platform.
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calcium availability but not its content modulates metal toxicity in Scenedesmus Quadricauda
Ecotoxicology and Environmental Safety, 2018Co-Authors: Jozef Kovacik, Slawomir DreslerAbstract:Abstract Impact of calcium nutrition (pre-culture on solid medium with standard or elevated Ca dose, i. e. 0.17 and 4.40 mM marked as low and high Ca) on acute metal toxicity (Cd, Mn and Pb, 24 h of exposure to 10 µM) in freshwater green alga Scenedesmus Quadricauda was studied. Surprisingly, Ca content differed only slightly between low and high Ca samples and applied metals rather suppressed its amount. Na content was higher in metal-exposed high Ca samples, indicating that Ca/Na ratio may affect accumulation of metals. Content of heavy metals increased in order Cd
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ascorbic acid affects short term response of Scenedesmus Quadricauda to cadmium excess
Algal Research-Biomass Biofuels and Bioproducts, 2017Co-Authors: Jozef Kovacik, Bořivoj Klejdus, Petr Babula, Josef HedbavnyAbstract:Abstract Impact of ascorbate biosynthetic inhibitor (lycorine, LYC) on short-term cadmium (Cd) action (1 h, 100 μM) was studied in the green alga Scenedesmus Quadricauda with 1 h or 24 h of LYC co-application. LYC suppressed Cd-induced increase in ascorbic acid and enhanced oxidative symptoms (ROS fluorescence) by modulating activities of antioxidative enzymes after 24 h of addition (decrease in superoxide dismutase, catalase and ascorbate peroxidase activities). Prolonged (24 h) exposure to LYC also affected content of Cd and quantitative changes of thiols (glutathione and phytochelatin 2) while Cd itself revealed interesting responses in algae maintained in the buffer for various time: these data indicate that in the studies involving axenic algal cultures, transfer of cells from sterile to non-sterile conditions modulates metal uptake. Among aliphatic organic acids, α-ketoglutaric, lactic and malic acids were variously influenced by Cd or lycorine, suggesting shift in the respiration and fermentation. It is concluded that ascorbic acid is involved in the protection of cells against Cd-induced ROS over-accumulation and metabolic changes were more expressive in the samples with 24 h co-application of LYC though side impacts of LYC cannot be excluded. DESI-Orbitrap MS for the identification and visualization of lycorine was also successfully tested here for the first time.
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impact of anions cations and ph on manganese accumulation and toxicity in the green alga Scenedesmus Quadricauda
Water Air and Soil Pollution, 2016Co-Authors: Pavel Svec, Jozef Kovacik, Petr Babula, Josef Hedbavny, Gabriela Rotkova, Bořivoj KlejdusAbstract:Accumulation of divalent manganese (Mn) and its toxicity in the green alga Scenedesmus Quadricauda was studied at circumneutral pH (6.5). A comparison of two applied concentrations (10 or 100 μM) of MnCl2, MnSO4, and Mn(NO3)2 indicated that mainly sulfate evoked higher Mn accumulation. On the other hand, nitrate rather depleted antioxidative enzyme activities (APX, CAT, SOD), leading to an increase in ROS formation as proven by fluorescence microscopy. Subsequent experiments revealed that increase in pH (from 4.5 to 9.5) increased also Mn content but typically depleted amounts of reduced glutathione and phytochelatin 2. We also measured the size of particles formed from the manganese salts at pH 9.5. Competitive experiment between Ca/K salts (CaCl2, CaSO4, Ca(NO3)2, KCl, K2SO4, KNO3) and Mn (as Mn sulfate) showed a negative relation between Ca and Mn amount but KNO3 stimulated Mn accumulation. Microscopy revealed that mainly K salts elevated plasma membrane damage (Acridine orange staining). Data indicate that not only pH but also accompanying anion affects Mn accumulation and that Ca salts may affect Mn toxicity.
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age affects not only metabolome but also metal toxicity in Scenedesmus Quadricauda cultures
Journal of Hazardous Materials, 2016Co-Authors: Jozef Kovacik, Bořivoj Klejdus, Petr Babula, Josef HedbavnyAbstract:Responses of Scenedesmus Quadricauda grown in vitro and differing in age (old culture-13 months, young culture-1 month) to short-term cadmium (Cd) or nickel (Ni) excess (24h) were compared. Higher age of the culture led to lower amount of chlorophylls, ascorbic acid and glutathione but higher signal of ROS. Surprisingly, sucrose was detected using DART-Orbitrap MS in both old and young culture and subsequent quantification confirmed its higher amount (ca. 3-times) in the old culture. Cd affected viability and ROS amount more negatively than Ni that could arise from excessive Cd uptake which was also higher in all treatments than in respective Ni counterparts. Surprisingly, nitric oxide was not extensively different in response to age or metals. Strong induction of phytochelatin 2 is certainly Cd-specific response while Ni also elevated ascorbate content. Krebs cycle acids were more accumulated in the young culture but they were rather elevated in the old culture (citric acid under Ni excess). We conclude that organic solid 'Milieu Bristol' medium we tested is suitable for long-term storage of unicellular green algae (also successfully tested for Coccomyxa sp. and Parachlorella sp.) and the impact of age on metal uptake may be useful for bioremediation purposes.
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physiology and methodology of chromium toxicity using alga Scenedesmus Quadricauda as model object
Chemosphere, 2015Co-Authors: Jozef Kovacik, Petr Babula, Josef Hedbavny, Olga Krystofova, Ivo ProvaznikAbstract:Abstract Physiological responses of Scenedesmus Quadricauda to Cr(VI) and Cr(III) excess were studied in buffer with circumneutral pH (6.5). Total Cr content was similar in low (1 μM of both oxidation states) but higher in 10 μM Cr(VI) treatment and high accumulation potential was detected (80–82% and 41–65% in 1 and 10 μM treatments, respectively). Specific fluorescence indicator (6-((anthracen-9-yl) methyleneamino)-2H-chromen-2-one) confirmed partial reduction of Cr(VI) to Cr(III) under exposure conditions. Viability and chlorophyll autofluorescence were more depleted by Cr(VI) while Cr(III) stimulated increase in ROS and lipid peroxidation. Antioxidative enzyme activities showed significantly higher values in 10 μM treatments of both Cr oxidation states. Depletion of mitochondrial proteins was not reflected in alteration of total soluble proteins indicating sensitivity of this organelle to Cr and TTC test showed no clear oxidation state-related effect. In this view, “Cr(VI) is not more toxic than Cr(III)” at least for some parameters. Subsequent study with the application of 10 μM Cr(VI) confirmed that HEPES buffer is more suitable exposure solution for toxicological studied than water or inorganic salts (higher chlorophyll autofluorescence was observed) and pH 6.5 is more suitable than low or high pH (4.5 or 8.5) in terms of Cr uptake. Another known Cr(III) fluorescence indicator (naphthalimide–rhodamine) also confirmed partial reduction of Cr(VI) to Cr(III) at acidic pH but only traces were seen at alkaline pH.
Mathias Ahii Chia - One of the best experts on this subject based on the ideXlab platform.
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toxicity of atrazine to Scenedesmus Quadricauda under different nitrogen concentrations
Environmental Earth Sciences, 2016Co-Authors: Mathias Ahii Chia, Suleiman Dauda, Talatu Zainab JibrilAbstract:Herbicides constitute a serious environmental problem because they can affect nontarget organisms. The toxicity of these chemicals depends on their interaction with prevailing environmental conditions. In this study, the effect of atrazine (ATR) (0.05, 0.5 and 5.0 mg L−1) at different nitrogen concentrations (1.8 × 10−4 and 1.8 × 10−5 M) on the growth, morphological variation, biomass production and antioxidant enzyme activities of the freshwater microalga Scenedesmus Quadricauda was investigated. Compared with the control, growth rate, dry weight and cell density were lower under limited nitrogen with or without ATR exposure. The proportion of multi-celled coenobial structures was generally higher in the control and ATR treatments with replete (1.8 × 10−4 M) nitrogen than that under limited nitrogen. Catalase and peroxidase activities decreased under nitrogen limitation and atrazine exposure. In conclusion, our results revealed that nitrogen levels influence the toxicity of atrazine to S. Quadricauda and possibly other algae in aquatic ecosystems.
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Algicidal effects of aqueous leaf extracts of neem (Azadirachta indica) on Scenedesmus Quadricauda (Turp.) de Brébission
Acta Botanica Brasilica, 2016Co-Authors: Mathias Ahii Chia, Jamiu Taiwo Akinsanmi, Y. Tanimu, Zakari LadanAbstract:The application of synthetic algaecides for the control of algae produces by-products that are sometimes toxic to the environment. There is a need for natural and cheap alternatives to synthetic algaecides. In the present study, we investigated the potential of aqueous crude extract of Azadirachta indica to inhibit the growth of Scenedesmus Quadricauda. Phytochemical screening of the extract revealed the presence of groups of bioactive compounds that are capable of inhibiting microalgal growth. Chlorophyll a concentration, dry weight production and cell density of microalga decreased with increasing crude extract concentration. After three days of exposure, the 1000 mg/L extract concentration resulted in complete growth inhibition and cell lysis. Furthermore, the ability of S. Quadricauda to form multi-celled coenobial structures was compromised in a concentration dependent manner. In general, catalase and peroxidase activities of the microalga were upregulated with increasing extract concentration. These results imply that aqueous neem extract may provide a cheap and ecofriendly alternative for the control of microalgae in aquatic ecosystems.
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combined effect of atrazine and copper on the growth biomass production morphology and antioxidant response of Scenedesmus Quadricauda
Phycologia, 2015Co-Authors: Mathias Ahii Chia, Sadiya Yunusa Galadima, Wisdom Sohunago JaphetAbstract:In recent years, various investigations have been carried out on the toxic effects of atrazine to different algae. However, none of these studies have considered the combined effects of metals and atrazine on any microalga. The toxicity of atrazine to microalgae depends on its interaction with the physical and chemical conditions prevalent in the aquatic ecosystem at the time of exposure. The aim of this study was to investigate the combined effect of copper (Cu) and atrazine on the growth, biomass production, morphological variation, protein production and antioxidant enzyme responses of Scenedesmus Quadricauda under controlled laboratory conditions. The combination of Cu and atrazine resulted in significantly lower growth and biomass production than Cu or atrazine alone. The ability of the alga to produce multicellular coenobia was significantly compromised after exposure to Cu and atrazine, while the proportion of unicells increased. Copper/atrazine stress stimulated total protein production and up-reg...
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lead induced antioxidant response and phenotypic plasticity of Scenedesmus Quadricauda turp de brebisson under different nitrogen concentrations
Journal of Applied Phycology, 2015Co-Authors: Mathias Ahii Chia, Promise Kalu Chimdirim, Wisdom Sohunago JaphetAbstract:The induction of antioxidant response and phenotypic plasticity of Scenedesmus Quadricauda after exposure to lead (Pb) (3.6 × 10−8 and 3.6 × 10−7 M) at different nitrogen (N) concentrations (1.8 × 10−4, 1.8 × 10−5, and 1.8 × 10−6 M) was investigated. The growth of the microalga was inhibited with decreasing N and increasing Pb concentrations. N limitation and Pb stress caused a decrease in biomass (cell density, dry weight, and chlorophyll a) production. Superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and glutathione S transferase (GST) activities generally increased with N limitation and/or increased Pb stress. CAT and POD activities decreased after 48 h, even though their activities were still higher than in those in the control, while GST and SOD activities increased throughout the N/Pb stress exposure period. The enzyme activities observed in S. Quadricauda showed a significant positive correlation with N/Pb stress. These results imply that aquatic biota may suffer differently from Pb toxicity, depending on the amount of nitrogen in the environment.
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the indigo blue dye decolorization potential of immobilized Scenedesmus Quadricauda
Water Air and Soil Pollution, 2014Co-Authors: Mathias Ahii Chia, Ojone Anne Odoh, Zakari LadanAbstract:In this study, Scenedesmus Quadricauda ABU12 was immobilized with sodium alginate to determine its potential for decolorizing indigo blue dye under different incubation conditions. The microalga was incubated at different pH (6.5–9.5), biomass concentrations (0.1–1.0 g l−1), dye concentrations (12–75 mg l−1) and temperatures (25–40°C). The concentration of biomass used significantly determined the rate of dye decolorization, as the lowest biomass concentration (0.10 g) was able to completely decolorize the dye by day 3, while the highest biomass concentration (1.00 g l−1) attained 100 % decolorization on day 4. Neutral pHs supported the highest dye decolorization rates compared alkaline pHs. The rate of dye decolorization had a linear relationship with the concentration of the dye in solution as increasing dye concentration in the medium significantly reduced the rate of decolorization (p < 0.05). At 25°C, the rate of dye decolorization was consistently higher from day 2 to the end of the experiment. Infra-red analyses of the algal biomass and the dye solution was done in Kbr by pressing between flat aperture plates of sodium chloride and scanning from 4,000 to 625 cm−1. This revealed the presence of functional groups associated with the biomass and dye that provided possible explanations for the decolorization of the dye under the different incubation conditions. These results showed that immobilized S. Quadricauda is capable of decolorizing indigo blue dye at low biomass when immobilized with sodium alginate. However, this was dependent on the incubation temperature and dye concentration.
Wisdom Sohunago Japhet - One of the best experts on this subject based on the ideXlab platform.
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combined effect of atrazine and copper on the growth biomass production morphology and antioxidant response of Scenedesmus Quadricauda
Phycologia, 2015Co-Authors: Mathias Ahii Chia, Sadiya Yunusa Galadima, Wisdom Sohunago JaphetAbstract:In recent years, various investigations have been carried out on the toxic effects of atrazine to different algae. However, none of these studies have considered the combined effects of metals and atrazine on any microalga. The toxicity of atrazine to microalgae depends on its interaction with the physical and chemical conditions prevalent in the aquatic ecosystem at the time of exposure. The aim of this study was to investigate the combined effect of copper (Cu) and atrazine on the growth, biomass production, morphological variation, protein production and antioxidant enzyme responses of Scenedesmus Quadricauda under controlled laboratory conditions. The combination of Cu and atrazine resulted in significantly lower growth and biomass production than Cu or atrazine alone. The ability of the alga to produce multicellular coenobia was significantly compromised after exposure to Cu and atrazine, while the proportion of unicells increased. Copper/atrazine stress stimulated total protein production and up-reg...
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lead induced antioxidant response and phenotypic plasticity of Scenedesmus Quadricauda turp de brebisson under different nitrogen concentrations
Journal of Applied Phycology, 2015Co-Authors: Mathias Ahii Chia, Promise Kalu Chimdirim, Wisdom Sohunago JaphetAbstract:The induction of antioxidant response and phenotypic plasticity of Scenedesmus Quadricauda after exposure to lead (Pb) (3.6 × 10−8 and 3.6 × 10−7 M) at different nitrogen (N) concentrations (1.8 × 10−4, 1.8 × 10−5, and 1.8 × 10−6 M) was investigated. The growth of the microalga was inhibited with decreasing N and increasing Pb concentrations. N limitation and Pb stress caused a decrease in biomass (cell density, dry weight, and chlorophyll a) production. Superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and glutathione S transferase (GST) activities generally increased with N limitation and/or increased Pb stress. CAT and POD activities decreased after 48 h, even though their activities were still higher than in those in the control, while GST and SOD activities increased throughout the N/Pb stress exposure period. The enzyme activities observed in S. Quadricauda showed a significant positive correlation with N/Pb stress. These results imply that aquatic biota may suffer differently from Pb toxicity, depending on the amount of nitrogen in the environment.
V. Ivanova - One of the best experts on this subject based on the ideXlab platform.
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Comparison of the phytotoxic effects of usnic acid on cultures of free-living alga Scenedesmus Quadricauda and aposymbiotically grown lichen photobiont Trebouxia erici.
Journal of chemical ecology, 2010Co-Authors: Martin Bačkor, Katarína Klemová, Miriam Bačkorová, V. IvanovaAbstract:The phytotoxic effects of the lichen secondary metabolite—usnic acid on cultures of free living alga—Scenedesmus Quadricauda (UTEX 76) and aposymbiotically grown lichen photobiont Trebouxia erici (UTEX 911) were assessed. We found a relatively strong inhibition effect of usnic acid on the growth of alga Scenedesmus, accompanied by an increase of cell size, an alteration of assimilation pigment composition, followed by strong degradation of chlorophyll a, a decrease of chlorophyll a fluorescence, and an increase of reactive oxygen species in the cells. The content of soluble proteins remained a stable parameter. Phytotoxicity of usnic acid on cultures of Trebouxia photobiont was significantly lower. Usnic acid in lichens may act as an allochemical that controls the division of photobiont cells, thereby regulating the balance between the photobiont and mycobiont forming thallus. Higher tolerance to usnic acid in Trebouxia cultures may be an adaptation resulting from the long term co-evolution of these algae with fungi that produce secondary metabolites.
