Influence of the Ca/Mg ratio on Cu resistance in three Silene armeria ecotypes adapted to calcareous soil or to different, Ni- or Cu-enriched, serpentine sites

Our plain-English summary of Influence of the Ca/Mg ratio on Cu resistance in three Silene armeria ecotypes adapted to calcareous soil or to different, Ni- or Cu-enriched, serpentine sites, by A. Lombini, M. Llugany, C. Poschenrieder, et al (Journal of Plant Physiology, 2003).

The study

• Authors: A. Lombini, M. Llugany, C. Poschenrieder, E. Dinelli, J. Barceló
• Journal: Journal of Plant Physiology
• Published: 2003;160(12):1451-6
• Cited by: 12 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

This hydroponic study addresses the influence of low (0.3) and high (4.0) Ca/Mg molar ratios on Cu resistance of Silene armeria ecotypes from different habitats: a calcareous soil (ecotype Cadriano), a Ni-rich serpentine site (ecotype Prinzera), and an acid Cu-mine spoil soil containing serpentinite (ecotype Vigonzano). Under control conditions, without excess Cu, only Cadriano was negatively affected by the low Ca/Mg ratio. Under both low and high Ca/Mg ratios Cu resistance followed the order Vigonzano more more than Prinzera > Cadriano. More efficient Cu exclusion accounted for enhanced Cu resistance in Prinzera. The low Ca/Mg ratio increased Cu uptake in Prinzera but did not worsen toxicity effects; i.e. the plants had higher internal Cu effect concentrations. In Vigonzano Cu resistance was enhanced by the low Ca/Mg ratio. This was due only in part to better Cu exclusion. Magnesium-induced tolerance to higher Cu tissue concentrations appears to be in ecotypes from serpentine and acid mine spoils, but not in plants from calcareous soil, the exposure to low Ca/Mg ratio favours internal detoxification of Cu by means of more efficient chelation and compartmentation.

In plain English

This was a laboratory study of plants, not of asbestos or of people. The authors grew Silene armeria, a flowering plant, from seeds collected at three sites: a calcareous garden soil (ecotype Cadriano), a nickel-rich serpentine site (Prinzera), and an acid copper-mine spoil soil containing serpentinite (Vigonzano). The plants were grown in nutrient solution with either a high (4.0) or a low (0.3) calcium-to-magnesium ratio. They were then exposed for 4 days to copper at 0.1 (control) up to 20 µmol/L. The authors measured root growth and copper, calcium and magnesium in the plant tissue. Without excess copper, only Cadriano roots were held back by the low ratio. Vigonzano was by far the most copper-resistant ecotype. Under excess copper, its roots grew significantly more with the low ratio. Root growth stopped completely in Prinzera between 10 and 20 µmol/L copper and in Cadriano between 5 and 10 µmol/L. High magnesium significantly increased copper uptake into Prinzera roots. The authors concluded that, in the ecotypes from serpentinite-containing soils but not in the calcareous-soil ecotype, a low ratio favours internal detoxification of copper.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Laboratory hydroponic (nutrient solution) plant experiment
• Who was studied: Plants of Silene armeria grown from seeds collected at three sites: Cadriano (calcareous, uncontaminated garden soil), Prinzera (Ni-rich serpentine site) and Vigonzano (Cu mine site containing serpentinite). Root growth data came from at least 8 plants per ecotype per treatment. Tissue analyses used three replicated samples per plant part, ecotype and treatment.
• Exposure: Copper (as CuSO4) in nutrient solution at 0.1 (control), 2, 5, 10 and 20 µmol/L for 4 days, combined with a Ca/Mg molar ratio of 4.0 (high) or 0.3 (low). Some combinations were not tested at the low ratio. No asbestos or other fiber exposure was studied.
• Main results:
  • Without excess Cu, Cadriano (calcareous-soil ecotype) showed inhibited root elongation at the low Ca/Mg ratio compared with the high ratio.
  • At both Ca/Mg ratios, the solution Cu concentration that completely stopped root elongation (EC100) lay between 10 and 20 µmol/L for Prinzera and between 5 and 10 µmol/L for Cadriano.
  • Vigonzano (Cu mine spoil ecotype) was the most Cu-resistant ecotype.
  • Under excess Cu, Vigonzano plants at the low Ca/Mg ratio had significantly higher root elongation than plants at the high ratio.
  • In Prinzera, Cu uptake into roots was significantly increased by the high Mg supply. Root Cu in Cadriano was not influenced by the Ca/Mg ratio.
  • At equal root Cu concentrations, high Ca favoured root elongation in Cadriano, while the opposite effect was seen in Prinzera and Vigonzano.
  • The more Cu-resistant Prinzera and Vigonzano did not, as a rule, show better exclusion of Cu from shoots than Cadriano.
• The authors' conclusion: The authors concluded that in ecotypes from soils containing serpentinite enriched with Ni or Cu, but not in the calcareous-soil ecotype, exposure to a low Ca/Mg ratio favours internal detoxification of Cu through more efficient chelation and compartmentation.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Chrysotile.

Medical terms in this study, explained in our Lexicon: Serpentine Group, Serpentinite.

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