Genetic architecture of zinc hyperaccumulation in Arabidopsis halleri: the essential role of QTL · environment interactions

H. Frérot (1) , M.-P. Faucon , G. Willems (1) , C. Godé (1) , Adeline Courseaux (1) , A. Darracq (1) , N. Verbruggen , Pierre Saumitou-Laprade (1)

1 GEPV - Génétique et évolution des populations végétales

This study sought to determine the main genomic regions that control zinc (Zn) hyperaccumulation in Arabidopsis halleri and to examine genotype · environment effects on phenotypic variance. To do so, quantitative trait loci (QTLs) were mapped using an interspecific A. halleri · Arabidopsis lyrata petraea F2 population. • The F2 progeny as well as representatives of the parental populations were cultivated on soils at two different Zn concentrations. A linkage map was constructed using 70 markers. • In both low and high pollution treatments, zinc hyperaccumulation showed high broad-sense heritability (81.9 and 74.7%, respectively). Five significant QTLs were detected: two QTLs specific to the low pollution treatment (chromosomes 1 and 4), and three QTLs identified at both treatments (chromosomes 3, 6 and 7). These QTLs explained 50.1 and 36.5% of the phenotypic variance in low and high pollution treatments, respectively. Two QTLs identified at both treatments (chromosomes 3 and 6) showed significant QTL · environment interactions. • The QTL on chromosome 3 largely colocalized with a major QTL previously identified for Zn and cadmium (Cd) tolerance. This suggests that Zn tolerance and hyperaccumulation share, at least partially, a common genetic basis and may have simultaneously evolved on heavy metal-contaminated soils.

Domaines: Génétique des populations [q-bio.PE]

H. Frérot, M.-P. Faucon, G. Willems, C. Godé, Adeline Courseaux, et al.. Genetic architecture of zinc hyperaccumulation in Arabidopsis halleri: the essential role of QTL · environment interactions. New Phytologist, 2010, 187, pp.355-367. ⟨10.1111/j.1469-8137.2010.03295.x⟩. ⟨hal-00489949⟩