GWA Mapping of Anthocyanin Accumulation Reveals Balancing Selection of MYB90 in Arabidopsis thaliana

• Published in: PloS one Vol. 10; no. 11; p. e0143212
• Main Authors: Bac-Molenaar, Johanna A, Fradin, Emilie F, Rienstra, Juriaan A, Vreugdenhil, Dick, Keurentjes, Joost J B
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 20-11-2015; Public Library of Science (PLoS)
• Subjects: Accumulation; Acids; Alleles; Amino acids; Amino Acids - chemistry; Analysis; Anthocyanins - metabolism; Arabidopsis; Arabidopsis - genetics; Arabidopsis thaliana; Biosynthesis; Calmodulin - chemistry; Chromosome 1; Chromosome Mapping; Chromosomes, Plant - ultrastructure; Climatic conditions; Deoxyribonucleic acid; DNA; EPS; Evolution, Molecular; Gene expression; Gene Frequency; Gene mapping; Gene polymorphism; Genes; Genetic aspects; Genetic Association Studies; Genetic polymorphisms; Genetic Variation; Genetics; Genomes; Genomics; Genotype; Groep Koornneef; Laboratories; Laboratorium voor Erfelijkheidsleer; Laboratorium voor Plantenfysiologie; Laboratory of Genetics; Laboratory of Plant Physiology; Mapping; Mutation; Negative selection; Nucleotide sequence; Osmotic stress; Phenotype; Phenotypic variations; Physiological aspects; Physiology; Polymorphism; Polymorphism, Single Nucleotide; Population genetics; Quantitative Trait Loci; Seeds; Selection, Genetic; Sequence Analysis, DNA; Spectrophotometry; Studies; Transcription factors; Transcription Factors - genetics; Netherlands
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0143212

Induction of anthocyanin accumulation by osmotic stress was assessed in 360 accessions of Arabidopsis thaliana. A wide range of natural variation, with phenotypes ranging from green to completely red/purple rosettes, was observed. A genome wide association (GWA) mapping approach revealed that sequence diversity in a small 15 kb region on chromosome 1 explained 40% of the variation observed. Sequence and expression analyses of alleles of the candidate gene MYB90 identified a causal polymorphism at amino acid (AA) position 210 of this transcription factor of the anthocyanin biosynthesis pathway. This amino acid discriminates the two most frequent alleles of MYB90. Both alleles are present in a substantial part of the population, suggesting balancing selection between these two alleles. Analysis of the geographical origin of the studied accessions suggests that the macro climate is not the driving force behind positive or negative selection for anthocyanin accumulation. An important role for local climatic conditions is, therefore, suggested. This study emphasizes that GWA mapping is a powerful approach to identify alleles that are under balancing selection pressure in nature.