Abstract Detail

Molecular Ecology

Oakley, Christopher [1].

Genetic and physiological mechanisms of cold acclimation and local adaptation.

Identifying the genetic and physiological mechanisms of local adaptation is a major goal of evolutionary biology. Of particular interest is the genetic basis of traits that are adaptive in some environments but result in fitness costs in contrasting environments. In locally adapted native populations of Arabidopsis thaliana from Italy and Sweden, quantitative trait loci underlying fitness tradeoffs across environments have been identified. Freezing tolerance is a key adaptive trait in Sweden and can only be induced after a sustained period of cold acclimation (cold, but non-freezing temperatures). Such cold acclimation is therefore an example of adaptive phenotypic plasticity, and such plasticity may be costly in the Italian environment where cold but non-freezing temperatures result in cold acclimation without a subsequent freeze. Quantitative trait loci for freezing tolerance have been identified that map closely to loci involved in fitness tradeoffs. Taken together, this suggests that cold acclimation in general and these loci in particular are involved in fitness tradeoffs across environments. The gene underlying one major freezing tolerance locus has been identified as the transcription factor CBF2, which is known to be a major regulator of cold acclimated freezing tolerance.The Italian allele for this gene contains a deletion which results in a non-functional CBF2 protein. Here we use near isogenic and genetically engineered lines (CRISPR-Cas9) designed to replicate the loss-of-function mutation in CBF2 in the Swedish genetic background. We quantify freezing tolerance for these lines and also examine how the loss of function mutation in CBF2 alter patterns of global gene expression (RNAseq) in response to cold acclimation. Our ultimate goal is to identify the downstream targets of CBF2 that are major players in cold acclimated freezing tolerance, and to evaluate their potential role in fitness tradeoffs across environments.

1 - Purdue University, Botany & Plant Pathology and the Center for Plant Biology, 915 W State Street, West Lafayette, IN, 47907, USA

Keywords:
Freezing tolerance
Cold acclimation
Adaptive phenotypic plasticity
Winter annual
local adaptation
Fitness tradeoffs.

Presentation Type: Oral Paper
Session: 22, Molecular Ecology
Location: 107/Mayo Civic Center
Date: Tuesday, July 24th, 2018
Time: 10:30 AM
Number: 22009
Abstract ID:283
Candidate for Awards:None