Gomphrena claussenii, a novel metal-hypertolerant bioindicator species, sequesters cadmium, but not zinc, in vacuolar oxalate crystals.
New Phytol
; 208(3): 763-75, 2015 Nov.
Article
em En
| MEDLINE
| ID: mdl-26083742
ABSTRACT
Gomphrena claussenii is a recently described zinc (Zn)- and cadmium (Cd)-hypertolerant Amaranthaceae species displaying a metal bioindicator Zn/Cd accumulation response. We investigated the Zn and Cd distribution in stem and leaf tissues of G. claussenii at the cellular level, and determined metabolite profiles to investigate metabolite involvement in Zn and Cd sequestration. Gomphrena claussenii plants exposed to high Zn and Cd supply were analysed by scanning electron microscopy with energy-dispersive X-ray (SEM-EDX) and micro-proton-induced X-ray emission (micro-PIXE). In addition, gas chromatography-time of flight-mass spectrometry (GC-TOF-MS) was used to determine metabolite profiles on high Zn and Cd exposure. Stem and leaf tissues of G. claussenii plants exposed to control and high Cd conditions showed the abundant presence of calcium oxalate (CaOx) crystals, but on high Zn exposure, their abundance was strongly reduced. Ca and Cd co-localized to the CaOx crystals in Cd-exposed plants. Citrate, malate and oxalate levels were all higher in shoot tissues of metal-exposed plants, with oxalate levels induced 2.6-fold on Zn exposure and 6.4-fold on Cd exposure. Sequestration of Cd in vacuolar CaOx crystals of G. claussenii is found to be a novel mechanism to deal with Cd accumulation and tolerance.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Zinco
/
Cádmio
/
Oxalato de Cálcio
/
Amaranthaceae
Idioma:
En
Revista:
New Phytol
Assunto da revista:
BOTANICA
Ano de publicação:
2015
Tipo de documento:
Article
País de afiliação:
Holanda