Project

Genetic analysis of heavy metal accumulation and tolerance in Noccaea caerulescens

Noccaea caerulescens is a heavy metal hyperaccumulator that has adapted completely to a life on heavy metal contaminated soil. Part of this adaptation is an exceptional tolerance to zinc, nickel and cadmium, but next to that plants are also able to accumulate these metals at extremely high concentrations in their aerial tissues (between 0.5-3% of its dry weight).

Background

These remarkable characteristics are investigated in order to elucidate the genes controlling the process, that will benefit the development of zinc biofortification for healthy food, phytoremediation of cadmium contaminated soil and phytomining of natural nickel-rich serpentine soils. A number of quantitative trait loci (QTL) and candidate genes have already been reported, but so far only few natural accessions and mapping populations have been examined. The recent development of genome-wide association studies (GWASs) and the availability of a whole genome sequence of N. caerulescens now allow a different approach, fully exploring the available natural variation in the species. Recently, more than 100 N. caerulescens accessions have been collected from across Europe to expand the resources of genetic variation which will allow the discovery of novel candidate genes by GWAS and related methods.

Aim

The aim of this study is to apply genome-wide association studies (GWAS) and Recombinant Inbred Line mapping; a) to explore the genetic architecture underlying the adaptation of N. caerulescens to Zn and Cd exposure; b) to determine candidate gene(s) associated with Zn and Cd accumulation and tolerance; and c) to identify the function of the most promising candidate genes.

Approach

Two types of N. caerulescens mapping populations, one based on natural accessions, the other on recombinant inbred lines (RILs), are studied to identify QTLs and subsequently the underlying candidate genes involved in zinc and cadmium accumulation and tolerance. These populations are genotyped by whole genome sequencing and phenotyped for heavy metal concentrations and life history traits. Candidate genes will be identified upon GWAS and QTL analysis and investigated in more details for their biological function using varioud molecular genetic approaches.

Student opportunities

We are open to applications for thesis projects! We have different thesis topics available, including projects with GWAS, QTL analysis, Molecular Techniques, Tissue Culture and Genetic Transformation. Are you interested? Contact Mark.Aarts@wur.nl.