Book with abstracts from the COST Action 0905 meeting in ... - UMB

ADAPTIVE MECHANISMS OF HYPERACCUMULATOR NOCCAEA
CAERULESCENS ECOTYPES WITH CONTRASTING METAL
HYPERACCUMULATION AND HYPERTOLERANCE TRAITS
Pauliina Halimaa 1 , Viivi Ahonen 1 , Attila Gyenesei 2 , Sirpa Kärenlampi 1 , Asta Laiho 2 ,
Petri Pehkonen 1 , Juha-Pekka Pursiheimo 2 , Henk Schat 3 , Marjo Tuomainen 1 , Arja
Tervahauta 1
1 University of Eastern Finland, Department of Biosciences, Finland;
2 Turku Centre for Biotechnology, University of Turku and Åbo Akademi University,
Finland; 3 Vrije Universiteit Amsterdam, Institute of Molecular Cell Biology, Netherlands
Hyperaccumulator, next-generation sequencing, Noccea caerulescens, transcriptome
Studies on the metal hyperaccumulator Noccaea caerulescens have revealed several
mechanisms that contribute to adaptation to metalliferous soils. Populations, however, vary
in their abilities to tolerate and accumulate metals, but the lack of genomic sequence has
hindered the discovery of the genes responsible for this variation. N. caerulescens is a
close relative of Arabidopsis thaliana with 88.5% sequence identity in coding region,
which has facilitated gene expression studies in N. caerulescens. The application of deep
sequencing technologies to transcriptomics permits a large-scale comparison of
transcriptomes for organisms without genomic sequence. We used SOLiD sequencing to
characterize root transcriptomes of three N. caerulescens accessions with contrasting metal
tolerance and accumulation patterns. Sequencing produced 250 million reads from which
70% were mapped to the A. thaliana genome. The 30% not mapped reads may comprise a
source for identifying novel genes from N. caerulescens. The A. thaliana genome has
33518 genes (TAIR9), and N. caerulescens reads mapped to 97% of them. Transcriptional
differences were found e.g. in metal ion homeostasis, defense response and secondary
metabolite biosynthesis. The data provide a comprehensive picture of root processes
among three N. caerulescens populations.