Linked Life Data

17404382

Source:http://linkedlifedata.com/resource/pubmed/id/17404382

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
2007-5-21
pubmed:abstractText
Zinc (Zn) hyperaccumulation is a constitutive property of Thlaspi caerulescens, whereas cadmium (Cd) hyperaccumulation varies greatly among different ecotypes. The molecular basis of this variation is unknown. Ecotypic differences in the sequences and expression of four representative ZIP family transporter genes were investigated. Genome analysis indicated the presence of at least two closely related copies of the TcIRT1 gene in both Ganges (high Cd accumulating) and Prayon (low Cd accumulating) ecotypes, with different copies being expressed in each, and, furthermore, the two genes potentially encode different length transcripts. The predominant transcript in Prayon was truncated, missing sequence coding for the putative metal-binding site and the five C-terminal transmembrane helices. The two ecotypes were grown hydroponically +/-Fe and Cd, and mRNA abundance determined for four ZIP genes. The four ZIP genes studied (TcIRT1, TcIRT2, TcZNT1, and TcZNT5) were expressed in roots only. TcIRT1 expression (full-length in Ganges, TcIRT1-1G; truncated in Prayon, TcIRT1-2P) was enhanced by Fe deficiency or by exposure to Cd. TcIRT2 expression was induced by Fe deficiency, but was unaffected by Cd exposure. TcZNT5-G showed greater expression in Prayon compared with Ganges. The functions of TcIRT1 from Ganges and Prayon and the Arabidopsis homologue were analysed by heterologous expression in yeast. All three IRT1 genes were able to facilitate growth on low Fe concentrations. Cd sensitivity of yeast was conferred in the order AtIRT1>TcIRT1-1G>TcIRT1-2P (truncated). Cd uptake after 4 h was only detectable following complementation by AtIRT1. The results suggest that although TcIRT1-G may be involved in Cd hyperaccumulation in the Ganges ecotype of T. caerulescens, the transporter expressed in yeast does not have an enhanced ability to transport Cd compared with AtIRT1. Therefore, the unique Cd-accumulating ability of the T. caerulescens Ganges ecotype must be due to the levels of expression of the protein or to other factors such as interacting proteins.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0022-0957
pubmed:author
pubmed:issnType
Print
pubmed:volume
58
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1717-28
pubmed:meshHeading
pubmed-meshheading:17404382-Amino Acid Sequence, pubmed-meshheading:17404382-Arabidopsis Proteins, pubmed-meshheading:17404382-Cadmium, pubmed-meshheading:17404382-Carrier Proteins, pubmed-meshheading:17404382-Cation Transport Proteins, pubmed-meshheading:17404382-Cloning, Molecular, pubmed-meshheading:17404382-Gene Expression Regulation, Plant, pubmed-meshheading:17404382-Genetic Complementation Test, pubmed-meshheading:17404382-Genome, Plant, pubmed-meshheading:17404382-Iron, pubmed-meshheading:17404382-Molecular Sequence Data, pubmed-meshheading:17404382-Phylogeny, pubmed-meshheading:17404382-Plant Proteins, pubmed-meshheading:17404382-RNA, Messenger, pubmed-meshheading:17404382-Saccharomyces cerevisiae, pubmed-meshheading:17404382-Sequence Alignment, pubmed-meshheading:17404382-Thlaspi, pubmed-meshheading:17404382-Zinc
pubmed:year
2007
pubmed:articleTitle
Expression and functional analysis of metal transporter genes in two contrasting ecotypes of the hyperaccumulator Thlaspi caerulescens.
pubmed:affiliation
Crop Performance and Improvement Division, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, UK.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't