Hyperaccumulation of Zn by Thlaspi caerulescens Can Ameliorate Zn Toxicity in the Rhizosphere of Cocropped Thlaspi arvense

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• 作者：Steven N. Whiting ; Jonathan R. Leake ; Steve P. McGrath ; and Alan J. M. Baker
• 刊名：Environmental Science & Technology
• 出版年：2001
• 出版时间：August 1, 2001
• 年：2001
• 卷：35
• 期：15
• 页码：3237 - 3241
• 全文大小：96K
• 年卷期：v.35,no.15(August 1, 2001)
• ISSN：1520-5851

文摘

The metal hyperaccumulating plant Thlaspi caerulescensis effective in depleting plant-available metals from the soil.We hypothesized that this reduction of toxic metals inthe rhizosphere of T. caerulescens would increase thegrowth of less metal-tolerant plants with their roots permittedto intermingle and develop coincident rhizospheres. Theextent of rhizosphere interaction between T. caerulescensand a coplanted nonaccumulator species, Thlaspi arvense,was controlled using barriers. Two media with elevatedconcentrations of water-extractable Zn were prepared byenriching one soil with zinc oxide (ZnO) or zinc sulfide(ZnS). The shoot mass of T. arvense was increased by 30%when its roots were permitted to intermingle with thoseof T. caerulescens in the ZnO treatment. The concomitant 2-3-fold reduction in shoot Zn concentration in T. arvenseconfirmed that its improved growth was associated withreduced uptake and phytotoxicity of Zn. Thlaspi arvense alsoshowed increased growth and reduced metal uptakewhen cocropped with T. caerulescens in the ZnS treatment.We conclude that the strong Zn accumulation by T.caerulescens might enhance the establishment anddevelopment of surrounding less-tolerant species on soilsthat are naturally- or anthropogenically-enriched withmetals.