RRC ID 70155
Author Kobayashi Y, Kuroda K, Kimura K, Southron-Francis JL, Furuzawa A, Kimura K, Iuchi S, Kobayashi M, Taylor GJ, Koyama H.
Title Amino acid polymorphisms in strictly conserved domains of a P-type ATPase HMA5 are involved in the mechanism of copper tolerance variation in Arabidopsis.
Journal Plant Physiol
Abstract Copper (Cu) is an essential element in plant nutrition, but it inhibits the growth of roots at low concentrations. Accessions of Arabidopsis (Arabidopsis thaliana) vary in their tolerance to Cu. To understand the molecular mechanism of Cu tolerance in Arabidopsis, we performed quantitative trait locus (QTL) analysis and accession studies. One major QTL on chromosome 1 (QTL1) explained 52% of the phenotypic variation in Cu tolerance in roots in a Landsberg erecta/Cape Verde Islands (Ler/Cvi) recombinant inbred population. This QTL regulates Cu translocation capacity and involves a Cu-transporting P(1B-1)-type ATPase, HMA5. The Cvi allele carries two amino acid substitutions in comparison with the Ler allele and is less functional than the Ler allele in Cu tolerance when judged by complementation assays using a T-DNA insertion mutant. Complementation assays of the ccc2 mutant of yeast using chimeric HMA5 proteins revealed that N923T of the Cvi allele, which was identified in the tightly conserved domain N(x)(6)YN(x)(4)P (where the former asparagine was substituted by threonine), is a cause of dysfunction of the Cvi HMA5 allele. Another dysfunctional HMA5 allele was identified in Chisdra-2, which showed Cu sensitivity and low capacity of Cu translocation from roots to shoots. A unique amino acid substitution of Chisdra-2 was identified in another strictly conserved domain, CPC(x)(6)P, where the latter proline was replaced with leucine. These results indicate that a portion of the variation in Cu tolerance of Arabidopsis is regulated by the functional integrity of the Cu-translocating ATPase, HMA5, and in particular the amino acid sequence in several strictly conserved motifs.
Volume 148(2)
Pages 969-80
Published 2008-10-1
DOI 10.1104/pp.108.119933
PII pp.108.119933
PMID 18701674
PMC PMC2556842
MeSH Adenosine Triphosphatases / genetics* Adenosine Triphosphatases / metabolism Alleles Amino Acid Motifs Amino Acid Sequence Amino Acid Substitution Arabidopsis / genetics* Arabidopsis / metabolism Arabidopsis Proteins / genetics* Arabidopsis Proteins / metabolism Conserved Sequence Copper / metabolism* DNA, Bacterial / genetics DNA, Plant / genetics Genes, Plant Genetic Complementation Test Genotype Molecular Sequence Data Mutagenesis, Insertional Phenotype Polymorphism, Genetic Quantitative Trait Loci Saccharomyces cerevisiae / genetics Saccharomyces cerevisiae / metabolism
IF 6.902
Arabidopsis / Cultured plant cells, genes sja