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Zinc and Cadmium Uptake by Hyperaccumulator Thlaspi caerulescens Grown in Nutrient Solution
Author(s) -
Brown S. L.,
Chaney R. L.,
Angle J. S.,
Baker A. J. M.
Publication year - 1995
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1995.03615995005900010020x
Subject(s) - hyperaccumulator , cadmium , shoot , phytoremediation , zinc , phytotoxicity , botany , chemistry , horticulture , biology , environmental chemistry , heavy metals , organic chemistry
Phytoremediation of heavy‐metal‐contaminated soils can be an inexpensive means to remove hazardous metals from soil. Two metallophytes, Thlaspi caerulescents (J. & C. Presl, a Zn and Cd hyperaccumulator) from Prayon, Belgium, and a Zn‐tolerant ecotype of bladder campion [ Silene vulgaris (Moench.) Garcke L.] from Palmerton, PA, were compared with tomato [ Lycopersicon lycopersicum (L.) Karsten, metal intolerant] in nutrient solution to characterize Zn and Cd uptake and tolerance. Zinc and Cd were added to solutions at a 50:1 molar ratio to simulate concentrations often found on contaminated sites. Seven treatment concentrations were used, ranging (in half‐log increments) from 3.16 µ M Zn + 0.063 µ M Cd to 10000 µ M Zn + 200 µ M Cd. Thlaspi caerulescens showed much greater tolerance to Zn/Cd treatments than the other species, with toxicity stress only apparent at the 10000 µ M Zn/200 µ M Cd treatment. In this treatment, shoot concentrations of Zn and Cd were 33600 and 1140 mg kg −1 , respectively. Thlaspi caerulescens was also more effective at translocating both Zn and Cd from solution to shoots. Zinc concentration in shoots of T. caerulescens was higher than the other species at all Zn/Cd treatments. Cadmium concentration in shoots of T. caerulescens were significantly higher than in bladder campion only at the 316 µ M Zn/6.32 µ M Cd treatment. This genotype of T. caerulescens may not hyperaccumulate Cd. However, extreme Zn and Cd uptake and tolerance is evident in T. caerulescens , with >25000 mg Zn kg −1 and 1000 mg Cd kg −1 before yield is reduced. Results suggest that T. caerulescens may be a candidate for the phytoremediation of Zncontaminated soils.