Abstract Detail

Molecular Ecology and Evolution

Pepper, Alan E. [1], Hawkins, Angela K. [2], Garza, Elyssa [3], Ivalu, Cacho [4], Adrian, Platts [5], Sharon, Strauss [6].

Caulanthus amplexicaulis: An emerging genetic model for the evolution of serpentine tolerance.

Serpentine barrens are a well-known ‘extreme’ terrestrial environment that is characterized by mineral nutrient deficiencies and toxic metals. To understand the evolutionary pathway and genetic basis of plant adaptation to serpentine soils, our lab is engaged in a multifaceted experimental effort that combines comparative transcriptomics, whole genome sequencing, QTL mapping, and phylogenetic approaches in Caulanthus amplexicaulis var. barbarae (Brassicacee), a rare North American serpentine endemic, and its sister taxon C. a. var. amplexicaulis, which is found on granite soils and is serpentine intolerant. Compared to its non-serpentine conspecific, C. a. var. barbarae shows superior tolerance to natural serpentine soils, as well as nickel, low calcium, low nitrogen (as nitrate), and low phosphorous in controlled media experiments. Importantly, both taxa are interfertile, self-fertile, have small genomes (~372 Mbp), and a very plastic generation time (as short as 6 weeks). Using these divergent taxa as parents, we have created a set of recombinant inbred lines (RILs) showing segregation for tolerance to Ni, low P, low N and low Ca, as well as for growth on natural serpentine soils. We have developed draft transcriptome and genome sequences for both parents, and created a genetic linkage map by whole-genome resequencing of RILs. Transcriptional components of tolerance to serpentine are being examined by RNA-seq. From these experiments, we plan to identify both the genetic underpinnings of serpentine tolerance and a genetic model to explain the phenomenon of serpentine endemism. Here we report our progress on these efforts.

1 - Department Of Biology, Texas A&M University, TAMUS 3258, College Station, TX, 77843, USA
2 - Texas A & M University, Biological Sciences, Texas A&M University Dept. Of Biology, 3258 TAMUS, College Station, TX, 77843-3258, USA
3 - Texas A&M University, Department of Biology, 100 Butler Hall, 3258 TAMUS, College Station, TX, 77843-3258, USA
4 - University Of California-Davis, One Shields Ave, Davis, CA, 95616, USA
5 - McGill University, Department of Biology , 1205 Docteur Penfield Ave., Montreal, Quebec, H3A 1B1, Canada
6 - University of California, Davis, Ecology and Evolutionary Biology, One Shields Ave. , Davis, CA, 94563, USA

Keywords:
Genomics
Transcriptome
edaphic endemism
QTL
adaptation
Metal
Nutrient.

Presentation Type: Oral Paper
Session: 40, Molecular Ecology and Evolution
Location: 102/Savannah International Trade and Convention Center
Date: Wednesday, August 3rd, 2016
Time: 11:00 AM
Number: 40011
Abstract ID:831
Candidate for Awards:None