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Use of lanthanides to alleviate the effects of metal ion-deficiency in Desmodesmus quadricauda (Sphaeropleales, Chlorophyta).

Goecke F, Jerez CG, Zachleder V, Figueroa FL, Bišová K, Řezanka T, Vítová M - Front Microbiol (2015)

Bottom Line: We found that nutrient stress reduced parameters of growth and photosynthesis, such as maximal quantum yield, relative electron transport rate, photon capturing efficiency and light saturation irradiance.In contrast, with manganese deprivation (and at even lower concentrations), lanthanides enhanced the deleterious effect on cellular growth and photosynthetic competence.These results show that lanthanides can replace essential elements, but their effects on microalgae depend on stress and the nutritional state of the microalgae, raising the possibility of environmental impacts at even low concentrations.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Cell Cycles of Algae, Centre Algatech, Institute of Microbiology Academy of Sciences of the Czech Republic Třeboň, Czech Republic.

ABSTRACT
Lanthanides are biologically non-essential elements with wide applications in technology and industry. Their concentration as environmental contaminants is, therefore, increasing. Although non-essential, lanthanides have been proposed (and even used) to produce beneficial effects in plants, even though their mechanisms of action are unclear. Recently, it was suggested that they may replace essential elements. We tested the effect of low concentrations of lanthanides on the common freshwater microalga Desmodesmus quadricauda, grown under conditions of metal ion-deficiency (lower calcium or manganese concentrations). Our goal was to test if lanthanides can replace essential metals in their functions. Physiological stress was recorded by studying growth and photosynthetic activity using a pulse amplitude modulation (PAM) fluorimeter. We found that nutrient stress reduced parameters of growth and photosynthesis, such as maximal quantum yield, relative electron transport rate, photon capturing efficiency and light saturation irradiance. After adding low concentrations of five lanthanides, we confirmed that they can produce a stimulatory effect on microalgae, depending on the nutrient (metal) deprivation. In the case of a calcium deficit, the addition of lanthanides partly alleviated the adverse effects, probably by a partial substitution of the element. In contrast, with manganese deprivation (and at even lower concentrations), lanthanides enhanced the deleterious effect on cellular growth and photosynthetic competence. These results show that lanthanides can replace essential elements, but their effects on microalgae depend on stress and the nutritional state of the microalgae, raising the possibility of environmental impacts at even low concentrations.

No MeSH data available.


Related in: MedlinePlus

Calcium treatment. The photosynthetic parameters in cultures of the alga Desmodesmus quadricauda grown either in complete mineral medium (Ctrl, red symbols, dashed curve) or in calcium- deficient mineral medium (Def, blue symbols, dashed curves) are shown. To calcium deficient cultures either the complete mineral medium was added (Rec, black symbols, solid line) or different lanthanides (Ce, Eu, Gd, La, Nd) as marked in individual panels. The photosynthetic parameters were: light-limited photosynthetic efficiency (α); maximum relative electron transport rates (rETRmax, μmol electrons m−2 s−1); maximal quantum yield (Fv/Fm); and light saturation irradiance (Ek, μmol electrons m−2 s−1). Supplementary information see Figure S3.
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Figure 3: Calcium treatment. The photosynthetic parameters in cultures of the alga Desmodesmus quadricauda grown either in complete mineral medium (Ctrl, red symbols, dashed curve) or in calcium- deficient mineral medium (Def, blue symbols, dashed curves) are shown. To calcium deficient cultures either the complete mineral medium was added (Rec, black symbols, solid line) or different lanthanides (Ce, Eu, Gd, La, Nd) as marked in individual panels. The photosynthetic parameters were: light-limited photosynthetic efficiency (α); maximum relative electron transport rates (rETRmax, μmol electrons m−2 s−1); maximal quantum yield (Fv/Fm); and light saturation irradiance (Ek, μmol electrons m−2 s−1). Supplementary information see Figure S3.

Mentions: The effects of treatment on in vivo chlorophyll fluorescence of D. quadricauda are shown in Figures 3, 4, and Table 5. Under complete mineral medium, the maximum quantum yield of PSII (Fv/Fm) showed no significant differences (p < 0.05) between the first and second days. Under these standard (replete) conditions, the Fv/Fm mean value was 0.66 ± 0.00 (Table 5). However, omission of either Ca2+ or Mn2+ from the culture medium significantly decreased the maximum quantum yield. These nutrient stresses (metal-limited conditions) in microalgae were detected by a 21% ± 0.05 decrease (Ca2+) or 88% ± 2.50 decrease (Mn2+) compared with the controls (mean ± SD, n = 3; Figures 3, 4, respectively). In the first 6 h, stresses produced by sampling, centrifugation and nutrient medium replacement was observable in all tests (control and treatments), with recovery within the first 24 h. Only in the case of Ca2+ (Figure 3), but not Mn2+-deficiency (Figure 4), did the addition of low concentrations of Ln3+ produce a recovery in Fv/Fm and apparently alleviated the symptoms of an ion-deficit.


Use of lanthanides to alleviate the effects of metal ion-deficiency in Desmodesmus quadricauda (Sphaeropleales, Chlorophyta).

Goecke F, Jerez CG, Zachleder V, Figueroa FL, Bišová K, Řezanka T, Vítová M - Front Microbiol (2015)

Calcium treatment. The photosynthetic parameters in cultures of the alga Desmodesmus quadricauda grown either in complete mineral medium (Ctrl, red symbols, dashed curve) or in calcium- deficient mineral medium (Def, blue symbols, dashed curves) are shown. To calcium deficient cultures either the complete mineral medium was added (Rec, black symbols, solid line) or different lanthanides (Ce, Eu, Gd, La, Nd) as marked in individual panels. The photosynthetic parameters were: light-limited photosynthetic efficiency (α); maximum relative electron transport rates (rETRmax, μmol electrons m−2 s−1); maximal quantum yield (Fv/Fm); and light saturation irradiance (Ek, μmol electrons m−2 s−1). Supplementary information see Figure S3.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4309186&req=5

Figure 3: Calcium treatment. The photosynthetic parameters in cultures of the alga Desmodesmus quadricauda grown either in complete mineral medium (Ctrl, red symbols, dashed curve) or in calcium- deficient mineral medium (Def, blue symbols, dashed curves) are shown. To calcium deficient cultures either the complete mineral medium was added (Rec, black symbols, solid line) or different lanthanides (Ce, Eu, Gd, La, Nd) as marked in individual panels. The photosynthetic parameters were: light-limited photosynthetic efficiency (α); maximum relative electron transport rates (rETRmax, μmol electrons m−2 s−1); maximal quantum yield (Fv/Fm); and light saturation irradiance (Ek, μmol electrons m−2 s−1). Supplementary information see Figure S3.
Mentions: The effects of treatment on in vivo chlorophyll fluorescence of D. quadricauda are shown in Figures 3, 4, and Table 5. Under complete mineral medium, the maximum quantum yield of PSII (Fv/Fm) showed no significant differences (p < 0.05) between the first and second days. Under these standard (replete) conditions, the Fv/Fm mean value was 0.66 ± 0.00 (Table 5). However, omission of either Ca2+ or Mn2+ from the culture medium significantly decreased the maximum quantum yield. These nutrient stresses (metal-limited conditions) in microalgae were detected by a 21% ± 0.05 decrease (Ca2+) or 88% ± 2.50 decrease (Mn2+) compared with the controls (mean ± SD, n = 3; Figures 3, 4, respectively). In the first 6 h, stresses produced by sampling, centrifugation and nutrient medium replacement was observable in all tests (control and treatments), with recovery within the first 24 h. Only in the case of Ca2+ (Figure 3), but not Mn2+-deficiency (Figure 4), did the addition of low concentrations of Ln3+ produce a recovery in Fv/Fm and apparently alleviated the symptoms of an ion-deficit.

Bottom Line: We found that nutrient stress reduced parameters of growth and photosynthesis, such as maximal quantum yield, relative electron transport rate, photon capturing efficiency and light saturation irradiance.In contrast, with manganese deprivation (and at even lower concentrations), lanthanides enhanced the deleterious effect on cellular growth and photosynthetic competence.These results show that lanthanides can replace essential elements, but their effects on microalgae depend on stress and the nutritional state of the microalgae, raising the possibility of environmental impacts at even low concentrations.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Cell Cycles of Algae, Centre Algatech, Institute of Microbiology Academy of Sciences of the Czech Republic Třeboň, Czech Republic.

ABSTRACT
Lanthanides are biologically non-essential elements with wide applications in technology and industry. Their concentration as environmental contaminants is, therefore, increasing. Although non-essential, lanthanides have been proposed (and even used) to produce beneficial effects in plants, even though their mechanisms of action are unclear. Recently, it was suggested that they may replace essential elements. We tested the effect of low concentrations of lanthanides on the common freshwater microalga Desmodesmus quadricauda, grown under conditions of metal ion-deficiency (lower calcium or manganese concentrations). Our goal was to test if lanthanides can replace essential metals in their functions. Physiological stress was recorded by studying growth and photosynthetic activity using a pulse amplitude modulation (PAM) fluorimeter. We found that nutrient stress reduced parameters of growth and photosynthesis, such as maximal quantum yield, relative electron transport rate, photon capturing efficiency and light saturation irradiance. After adding low concentrations of five lanthanides, we confirmed that they can produce a stimulatory effect on microalgae, depending on the nutrient (metal) deprivation. In the case of a calcium deficit, the addition of lanthanides partly alleviated the adverse effects, probably by a partial substitution of the element. In contrast, with manganese deprivation (and at even lower concentrations), lanthanides enhanced the deleterious effect on cellular growth and photosynthetic competence. These results show that lanthanides can replace essential elements, but their effects on microalgae depend on stress and the nutritional state of the microalgae, raising the possibility of environmental impacts at even low concentrations.

No MeSH data available.


Related in: MedlinePlus