| 1. |
- Carlsson, Anders, et al.
(författare)
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Cell membrane integrity, callose accumulation, and root growth in aluminum-stressed sorghum seedlings
- 2014
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Ingår i: Biologia Plantarum. - : Institute of Experimental Botany. - 0006-3134 .- 1573-8264. ; 58, s. 768-772
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Tidskriftsartikel (refereegranskat)abstract
- Aluminum stress usually reduces plant root growth due to the accumulation of Al in specific zones of the root apex. The objectives of this study were to determine the localization of Al in the root apex of Sorghum bicolor (L.) Moech. and its effects on membrane integrity, callose accumulation, and root growth in selected cultivars. Seedlings were grown in a nutrient solution containing 0, 27, or 39 mu M Al3+ for 24, 48, and 120 h. The Al stress significantly reduced root growth, especially after 48 and 120 h of exposure. A higher Al accumulation, determined by fluorescence microscopy after staining with a Morin dye, occurred in the root extension zone of the sensitive cultivar than in the tolerant cultivar. The membrane damage and callose accumulation were also higher in the sensitive than resistant cultivar. It was concluded that the Al stress significantly reduced root growth through the accumulation of Al in the root extension zone, callose accumulation, and impairment of plasma membrane integrity.
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| 2. |
- Landberg, Tommy, et al.
(författare)
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Strategies of cadmium and zinc resistance in willow by regulation of net accumulation
- 2011
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Ingår i: Biologia plantarum. - : Institute of Experimental Botany. - 0006-3134 .- 1573-8264. ; 55:1, s. 133-140
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Tidskriftsartikel (refereegranskat)abstract
- This work was performed to find out if metal resistant clones of Salix viminalis L. are capable to achieve high resistance to the metals by regulating their net accumulation. Salix clones with low or high resistance in combination with low or high accumulation capacity of either Zn or Cd were cultivated from cuttings in nutrient solution. The investigation included leakage and uptake experiments using (65)Zn or (109)Cd and analysis of root cation exchange capacity (CEC). Some plants were pre-treated with unlabeled 0.5 mu M Cd or 2.5 mu M Zn 24 h prior to the experiments to induce possible tolerance mechanisms. To find out if the regulation was a metabolic process, experiments were also performed with 2,4-dinitrophenol (DNP). Clones with high resistance and low Cd accumulation had higher efflux of Cd compared to the other clones, in both untreated and Cd pre-treated plants. This indicates a constitutive property to lower Cd accumulation by high Cd leakage. Pre-treatment with 0.5 mu M Cd diminished the Cd net uptake to a level near zero in all clones, likely to be due to decreased the Cd uptake. In contrast, resistant clones with high Cd accumulation had the highest root CEC, which may be used to bind up Cd in the free space. No clear regulation of Zn net uptake was found in Zn-resistant clones. Pre-treatment with Zn decreased the uptake of Zn into the free space in Zn-resistant clones. The resistant high-accumulating clones, however, showed the highest leakage of Zn in both untreated and pre-treated plants, a constitutive process not related to high accumulation. Neither the influx nor the efflux of Cd or Zn was affected by DNP indicating passive transport across the plasma membrane.
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| 3. |
- Larsson Jönsson, Helene, et al.
(författare)
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Effects of pH and nitrogen on cadmium uptake in potato
- 2013
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Ingår i: Biologia Plantarum. - : Institute of Experimental Botany. - 0006-3134 .- 1573-8264. ; 57, s. 788-792
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Tidskriftsartikel (refereegranskat)abstract
- This study investigated the effects of pH and nitrogen form and concentration on cadmium (Cd) uptake by potato (Solanum tuberosum L.) grown in hydroponic culture. Potato plants grown in a pH-buffered nutrient solution for 10 d were exposed for 24 h to 25 nM CdCl2 labelled with Cd-109. Plants showed a significantly higher Cd uptake and accumulation at pH 6.5 than at pH 4.5 and 5.5. Nitrogen supplied as nitrate (NO3 (-)) generally resulted in a higher Cd uptake and accumulation than N supplied as ammonium (NH4 (+)). This effect was most pronounced at pH 6.5. The N concentration increasing from 6.5 to 26 mM resulted in a decreased Cd influx when either NO3 (-) or NH4 (+) was used. Cd translocation to the shoot was increased when NO3 (-) was used as the sole N source. In conclusion, pH had a strong influence on Cd uptake by roots and N form is especially important for Cd translocation within the potato plant.
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