Two basic-helix-loop-helix genes (MYC-146 and GL3) from Arabidopsis can activate anthocyanin biosynthesis in a white-flowered Matthiola incana mutant

Plant Mol Biol. 2003 Jun;52(3):679-88. doi: 10.1023/a:1024852021124.


Basic helix-loop-helix (bHLH) proteins, similar to mammalian Myc transcription factors, regulate the anthocyanin biosynthetic pathway in both monocots and dicots. Two Arabidopsis bHLH genes, GLABRA3 (GL3) and MYC-146, encode proteins that are similar throughout the predicted amino acid sequence to R and DELILA, which regulate anthocyanin production in maize and snapdragon, respectively. Northern blot analysis indicates that MYC-146 is most highly expressed in flower buds and flowers. Expression of a MYC-146 cDNA from the CaMV 35S promoter was unable to complement the anthocyanin deficiency in a ttg1 mutant of Arabidopsis and resulted in no obvious phenotypic change in Columbia plants. However, transient expression of GL3 and MYC-146 upon microprojectile bombardment of petals of a white-flowered mutant of Matthiola incana was able to complement anthocyanin deficiency. The lack of anthocyanin-deficient Arabidopsis mutants mapping to the locations of GL3 and MYC-146 suggests that the two bHLH proteins may be partially redundant and overlap in function.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Anthocyanins / biosynthesis*
  • Arabidopsis Proteins / genetics*
  • Basic Helix-Loop-Helix Leucine Zipper Transcription Factors
  • Basic Helix-Loop-Helix Transcription Factors
  • Blotting, Northern
  • Brassicaceae / genetics
  • Brassicaceae / metabolism*
  • Carrier Proteins / genetics*
  • DNA, Plant / chemistry
  • DNA, Plant / genetics
  • DNA, Plant / isolation & purification
  • Gene Expression Regulation, Plant
  • Genetic Complementation Test
  • Helix-Loop-Helix Motifs / genetics*
  • Molecular Sequence Data
  • Mutation
  • Phenotype
  • Plants, Genetically Modified
  • RNA, Plant / genetics
  • RNA, Plant / metabolism
  • Sequence Alignment
  • Sequence Analysis, DNA
  • Sequence Homology, Amino Acid
  • Trans-Activators / genetics*


  • Anthocyanins
  • Arabidopsis Proteins
  • Basic Helix-Loop-Helix Leucine Zipper Transcription Factors
  • Basic Helix-Loop-Helix Transcription Factors
  • Carrier Proteins
  • DNA, Plant
  • GL3 protein, Arabidopsis
  • MYC2 protein, Arabidopsis
  • RNA, Plant
  • Trans-Activators