Is chloride toxic to seed germination in mixed-salt environments? A case study with the coastal halophyte Suaeda maritima in the presence of seawater
Most salt tolerant plants, halophytes, use seed germination for natural regeneration. However, germination in mixed-salt environments such as seawater is poorly understood and ion toxicity by Cl−, the most highly concentrated ion in seawater, is rarely considered over Na+. Here, we investigate Cl− t...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2021-12-01
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| Series: | Plant Stress |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2667064X21000294 |
| _version_ | 1819043056078290944 |
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| author | Charlotte E. Seal Timothy J. Flowers Clément Esnaud Margaret Yeo Adele Muscolo |
| author_facet | Charlotte E. Seal Timothy J. Flowers Clément Esnaud Margaret Yeo Adele Muscolo |
| author_sort | Charlotte E. Seal |
| collection | DOAJ |
| description | Most salt tolerant plants, halophytes, use seed germination for natural regeneration. However, germination in mixed-salt environments such as seawater is poorly understood and ion toxicity by Cl−, the most highly concentrated ion in seawater, is rarely considered over Na+. Here, we investigate Cl− toxicity in the germination of the halophyte Suaeda maritima in the presence of artificial seawater (ASW). Seeds were germinated at 15/5 °C in dilutions of ASW and at concentrations of NaCl, MgCl2, CaCl2 and KCl as found in ASW. Solutions of polyethylene glycol (PEG) were used for osmotic comparison. Germination percentage and normal seedlings were quantified. Non-germinated seeds were tested for recovery on water. Germination rate (1/t50) was used in a halotime model to quantify the maximum concentration of Cl− (Cl−max) and Na+ (Na+max) for germination. Germination was most negatively affected when all salts were combined in the concentrations found in ASW. Recovery of non-germinated seeds from all salt treatments on water was low, but all germinated seeds formed normal seedlings. Germination on ASW was higher than on iso-osmotic solutions of PEG. The 1/t50 decreased with increasing Cl− and Na+ concentration, indicating maximum thresholds to germination at 1381 mM (Cl−max) and 1262 mM (Na+max). The results indicate that ASW does not produce an osmotic limitation to the germination of S. maritima, and exposure to salt ions can even promote germination. However, ion toxicity is the major limitation, with Cl− similarly as toxic as Na+. In mixed-salt environments such as seawater, Cl− toxicity should not be overlooked. |
| first_indexed | 2024-12-21T09:50:42Z |
| format | Article |
| id | doaj.art-f6e350fd69544507966c0ddc4b68f4df |
| institution | Directory Open Access Journal |
| issn | 2667-064X |
| language | English |
| last_indexed | 2024-12-21T09:50:42Z |
| publishDate | 2021-12-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Plant Stress |
| spelling | doaj.art-f6e350fd69544507966c0ddc4b68f4df2022-12-21T19:08:12ZengElsevierPlant Stress2667-064X2021-12-012100030Is chloride toxic to seed germination in mixed-salt environments? A case study with the coastal halophyte Suaeda maritima in the presence of seawaterCharlotte E. Seal0Timothy J. Flowers1Clément Esnaud2Margaret Yeo3Adele Muscolo4Royal Botanic Gardens, Kew, Wakehurst, Ardingly, West Sussex, RH17 6TN, UK; Corresponding author.School of Life Sciences, University of Sussex, Brighton, BN1 9QG, UKRoyal Botanic Gardens, Kew, Wakehurst, Ardingly, West Sussex, RH17 6TN, UKRoyal Botanic Gardens, Kew, Wakehurst, Ardingly, West Sussex, RH17 6TN, UKAgriculture Department, Mediterranea University, Feo di Vito, 89124 Reggio Calabria, ItalyMost salt tolerant plants, halophytes, use seed germination for natural regeneration. However, germination in mixed-salt environments such as seawater is poorly understood and ion toxicity by Cl−, the most highly concentrated ion in seawater, is rarely considered over Na+. Here, we investigate Cl− toxicity in the germination of the halophyte Suaeda maritima in the presence of artificial seawater (ASW). Seeds were germinated at 15/5 °C in dilutions of ASW and at concentrations of NaCl, MgCl2, CaCl2 and KCl as found in ASW. Solutions of polyethylene glycol (PEG) were used for osmotic comparison. Germination percentage and normal seedlings were quantified. Non-germinated seeds were tested for recovery on water. Germination rate (1/t50) was used in a halotime model to quantify the maximum concentration of Cl− (Cl−max) and Na+ (Na+max) for germination. Germination was most negatively affected when all salts were combined in the concentrations found in ASW. Recovery of non-germinated seeds from all salt treatments on water was low, but all germinated seeds formed normal seedlings. Germination on ASW was higher than on iso-osmotic solutions of PEG. The 1/t50 decreased with increasing Cl− and Na+ concentration, indicating maximum thresholds to germination at 1381 mM (Cl−max) and 1262 mM (Na+max). The results indicate that ASW does not produce an osmotic limitation to the germination of S. maritima, and exposure to salt ions can even promote germination. However, ion toxicity is the major limitation, with Cl− similarly as toxic as Na+. In mixed-salt environments such as seawater, Cl− toxicity should not be overlooked.http://www.sciencedirect.com/science/article/pii/S2667064X21000294Chloride toxicityHalophyteHalotime modelSalinitySeed germination |
| spellingShingle | Charlotte E. Seal Timothy J. Flowers Clément Esnaud Margaret Yeo Adele Muscolo Is chloride toxic to seed germination in mixed-salt environments? A case study with the coastal halophyte Suaeda maritima in the presence of seawater Plant Stress Chloride toxicity Halophyte Halotime model Salinity Seed germination |
| title | Is chloride toxic to seed germination in mixed-salt environments? A case study with the coastal halophyte Suaeda maritima in the presence of seawater |
| title_full | Is chloride toxic to seed germination in mixed-salt environments? A case study with the coastal halophyte Suaeda maritima in the presence of seawater |
| title_fullStr | Is chloride toxic to seed germination in mixed-salt environments? A case study with the coastal halophyte Suaeda maritima in the presence of seawater |
| title_full_unstemmed | Is chloride toxic to seed germination in mixed-salt environments? A case study with the coastal halophyte Suaeda maritima in the presence of seawater |
| title_short | Is chloride toxic to seed germination in mixed-salt environments? A case study with the coastal halophyte Suaeda maritima in the presence of seawater |
| title_sort | is chloride toxic to seed germination in mixed salt environments a case study with the coastal halophyte suaeda maritima in the presence of seawater |
| topic | Chloride toxicity Halophyte Halotime model Salinity Seed germination |
| url | http://www.sciencedirect.com/science/article/pii/S2667064X21000294 |
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