Genetics of water use physiology in locally adapted Arabidopsis thaliana.
Identifying the genetic basis of adaptation to climate has long been a goal in evolutionary biology and has applications in agriculture. Adaptation to drought represents one important aspect of local adaptation, and drought is the major factor limiting agricultural yield. We examined local adaptation between Sweden and Italy Arabidopsis thaliana ecotypes, which show contrasting levels of water availability in their local environments. To identify quantitative trait loci (QTL) controlling water use physiology traits and adaptive trait QTL (genomic regions where trait QTL and fitness QTL colocalize), we performed QTL mapping on 374F9 recombinant inbred lines in well-watered and terminal drought conditions. We found 72 QTL (32 in well-watered, 31 in drought, 9 for plasticity) across five water use physiology traits: δ(13)C, rosette area, dry rosette weight, leaf water content and percent leaf nitrogen. Some of these genomic regions colocalize with fitness QTL and with other physiology QTL in defined hotspots. In addition, we found evidence of both constitutive and inducible water use physiology QTL. Finally, we identified highly divergent candidate genes, in silico. Our results suggest that many genes with minor effects may influence adaptation through water use physiology and that pleiotropic water use physiology QTL have fitness consequences.
Department of Bioagricultural Sciences & Pest Management, Colorado State University, Fort Collins, CO 80523, USA. Electronic address: julius.mojica@duke.edu.
Julius P
JP
Mojica
Department of Bioagricultural Sciences & Pest Management, Colorado State University, Fort Collins, CO 80523, USA.
Jack
J
Mullen
Department of Integrative Biology, University of Texas, Austin, TX 78701, USA.
John T
JT
Lovell
Department of Bioagricultural Sciences & Pest Management, Colorado State University, Fort Collins, CO 80523, USA.
J Grey
JG
Monroe
Department of Bioagricultural Sciences & Pest Management, Colorado State University, Fort Collins, CO 80523, USA.
John R
JR
Paul
Department of Plant Biology, Michigan State University, East Lansing, MI 48824, USA.
Christopher G
CG
Oakley
Department of Bioagricultural Sciences & Pest Management, Colorado State University, Fort Collins, CO 80523, USA.
John K
JK
McKay
D000222:Adaptation, Physiological / Q000235:genetics; D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism; D002874:Chromosome Mapping; D005838:Genotype; D007558:Italy; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism; D040641:Quantitative Trait Loci; D013548:Sweden; D014867:Water / Q000378:metabolism*
D014867:Water
Adaptation; Constitutive; Fitness; Inducible; Plasticity; QTL; Water-stress