Zn2+ -induced changes at the root level account for the increased tolerance of acclimated tobacco plants
© The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology.
| Veröffentlicht in: | Journal of experimental botany. - 1985. - 65(2014), 17 vom: 15. Sept., Seite 4931-42 |
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| Weitere Verfasser: | , , , , , , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2014
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| Zugriff auf das übergeordnete Werk: | Journal of experimental botany |
| Schlagworte: | Journal Article Research Support, Non-U.S. Gov't Acclimation Nicotiana tabacum heavy-metal toxicity membrane potential stomatal conductance transporter vacuole. Chlorophyll mehr... |
| Zusammenfassung: | © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology. Evidence suggests that heavy-metal tolerance can be induced in plants following pre-treatment with non-toxic metal concentrations, but the results are still controversial. In the present study, tobacco plants were exposed to increasing Zn2+ concentrations (up to 250 and/or 500 μM ZnSO4) with or without a 1-week acclimation period with 30 μM ZnSO4. Elevated Zn2+ was highly toxic for plants, and after 3 weeks of treatments there was a marked (≥50%) decline in plant growth in non-acclimated plants. Plant acclimation, on the other hand, increased plant dry mass and leaf area up to 1.6-fold compared with non-acclimated ones. In non-acclimated plants, the addition of 250 μM ZnSO4 led to transient membrane depolarization and stomatal closure within 24h from the addition of the stress; by contrast, the acclimation process was associated with an improved stomatal regulation and a superior ability to maintain a negative root membrane potential, with values on average 37% more negative compared with non-acclimated plants. The different response at the plasma-membrane level between acclimated and non-acclimated plants was associated with an enhanced vacuolar Zn2+ sequestration and up to 2-fold higher expression of the tobacco orthologue of the Arabidopsis thaliana MTP1 gene. Thus, the acclimation process elicited specific detoxification mechanisms in roots that enhanced Zn2+ compartmentalization in vacuoles, thereby improving root membrane functionality and stomatal regulation in leaves following elevated Zn2+ stress |
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| Beschreibung: | Date Completed 28.05.2015 Date Revised 21.03.2024 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1460-2431 |
| DOI: | 10.1093/jxb/eru251 |