Natural variation for anthocyanin accumulation under high-light and low-temperature stress is attributable to the ENHANCER OF AG-4 2 (HUA2) locus in combination with PRODUCTION OF ANTHOCYANIN PIGMENT1 (PAP1) and PAP2

New Phytol. 2015 Apr;206(1):422-35. doi: 10.1111/nph.13177. Epub 2014 Nov 26.


Growing conditions combining high light intensities and low temperatures lead to anthocyanin accumulation in plants. This response was contrasted between two Arabidopsis thaliana accessions, which were used to decipher the genetic and molecular bases underlying the variation of this response. Quantitative trait loci (QTLs) for flowering time (FT) and anthocyanin accumulation under a high-light and low-temperature scenario versus a control environment were mapped. Major QTLs were confirmed using near-isogenic lines. Candidate genes were examined using mutants and gene expression studies as well as transgenic complementation. Several QTLs were found for FT and for anthocyanin content, of which one QTL co-located at the ENHANCER OF AG-4 2 (HUA2) locus. That HUA2 is a regulator of both pathways was confirmed by the analysis of loss-of-function mutants. For a strong expression of anthocyanin, additional allelic variation was detected for the PRODUCTION OF ANTHOCYANIN PIGMENT1 (PAP1) and PAP2 genes which control the anthocyanin pathway. The genetic control of variation for anthocyanin content was dissected in A. thaliana and shown to be affected by a common regulator of flowering and anthocyanin biosynthesis together with anthocyanin-specific regulators.

Keywords: Arabidopsis thaliana; HUA2; PAP1; PAP2; anthocyanin; epistasis; flowering time; quantitative trait loci.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alleles
  • Anthocyanins / metabolism*
  • Arabidopsis / genetics*
  • Arabidopsis / metabolism
  • Arabidopsis / radiation effects
  • Arabidopsis Proteins / genetics*
  • Arabidopsis Proteins / metabolism
  • Cold Temperature
  • Databases, Genetic
  • Environment
  • Flowers / genetics
  • Flowers / metabolism
  • Gene Expression
  • Light
  • Pancreatitis-Associated Proteins
  • Quantitative Trait Loci / genetics*
  • Regulatory Sequences, Nucleic Acid
  • Reproduction
  • Transcription Factors / genetics*
  • Transcription Factors / metabolism


  • Anthocyanins
  • Arabidopsis Proteins
  • HUA2 protein, Arabidopsis
  • PAP1 protein, Arabidopsis
  • PAP2 protein, Arabidopsis
  • Pancreatitis-Associated Proteins
  • REG3A protein, human
  • Transcription Factors