Abstract
Copper is an essential element that plays critical role in various biological processes, but its accumulation in soil causes growth inhibition of the roots. To identify major genes regulating variation of Cu-tolerance among natural variation, we performed QTL analyses using two sets of RILs of A.thaliana (Ler/Col and Ler/Cvi). One of the QTL shared by both populations on the lower arm of chromosome 1 (QTL1) can explain about 40% of the Cu-tolerance phenotypic variation of Ler/Cvi RILs. The QTL1 collocate a Cu-exporting ATPase, HMA5, which had been characterized its critical function of Cu-tolerance by reverse-genetics approach by Salk-Institute group. Complementation test by crossing between T-DNA insertion mutant and parental lines can fit the additive effect of the QTL1. These results indicate HMA5 is QTL gene for Cu-tolerance. The QTL1 interact lower arm of the chromosome 5 that includes several candidate genes that can functionally interact with HMA5.
