Abstract
Throughout the world anthropogenic activity has resulted in enhanced soil nickel (Ni 2+) levels, which may negatively affect plant productivity. The physiological background of Ni 2+ phytotoxicity is still largely unclear. Ten-day expo-sures of Brassica rapa seedlings to 1, 2 and 5 μM NiCl2 resulted in strongly enhanced tissue Ni levels, a decreased biomass production and leaf chlorosis at ≥ 2 μM Ni 2+. At 5 μM Ni 2+ plant growth was completely halted. Ni toxicity occurred when the content of the shoot exceeded 1.0 μmol g –1 dry weight and that of the root, 23 μmol g –1 dry weight. Ni 2+ exposure at ≤ 2 μM only slightly affected the mineral nutrient content of both shoot and root. Hence, Ni 2+ exposure hardly affected the sulfur metabo-lite content of the plant. At ≥ 1 μM Ni2+ the total sulfur content of the root was only slightly lowered, which could fully be ascribed to a decreased sulfate content. Moreover, the water-soluble non-protein thiol content of both shoot and root was only enhanced at 5 μM Ni2+ . From these results it was clear that sulfur metabolism was unlikely to be directly involved in the Ni 2+ tolerance mechanisms of B. rapa.
Original language | English |
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Pages (from-to) | 473-478 |
Number of pages | 6 |
Journal | Journal of Cultivated Plants |
Volume | 72 |
Issue number | 9 |
DOIs | |
Publication status | Published - 1 Sept 2020 |
Externally published | Yes |
Keywords
- glutathione
- heavy metals
- mineral composition
- nickel
- sulfur
- thiols
- toxic metals