A Novel bHLH Transcription Factor Involved in Regulating Anthocyanin Biosynthesis in Chrysanthemums (Chrysanthemum morifolium Ramat.)

PLoS One. 2015 Nov 30;10(11):e0143892. doi: 10.1371/journal.pone.0143892. eCollection 2015.

Abstract

Chrysanthemums (Chrysanthemum morifolium Ramat.) exhibit a variety of flower colors due to their differing abilities to accumulate anthocyanins. One MYB member, CmMYB6, has been verified as a transcription regulator of chrysanthemum genes involved in anthocyanin biosynthesis; however, the co-regulators for CmMYB6 remain unclear in chrysanthemum. Here, the expression pattern of CmbHLH2, which is clustered in the IIIf bHLH subgroup, was shown to be positively correlated with the anthocyanin content of cultivars with red, pink and yellow flower colors, respectively. CmbHLH2 significantly upregulated the CmDFR promoter and triggered anthocyanin accumulation when co-expressed with CmMYB6. Yeast one-hybrid analyses indicated that CmbHLH2 was able to bind directly to the CmDFR promoter. Moreover, yeast two-hybrid assays indicated protein-protein interaction between CmbHLH2 and CmMYB6. These results suggest that CmbHLH2 is the essential partner for CmMYB6 in regulating anthocyanin biosynthesis in chrysanthemum.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anthocyanins / biosynthesis*
  • Basic Helix-Loop-Helix Transcription Factors / genetics*
  • Basic Helix-Loop-Helix Transcription Factors / metabolism*
  • Chrysanthemum / genetics
  • Chrysanthemum / metabolism*
  • Cloning, Molecular / methods
  • Flowers / chemistry
  • Gene Expression Regulation, Plant
  • Genes, Plant
  • Multigene Family
  • Phylogeny
  • Pigments, Biological / genetics
  • Plant Proteins / genetics
  • Plant Proteins / metabolism
  • Promoter Regions, Genetic
  • Two-Hybrid System Techniques

Substances

  • Anthocyanins
  • Basic Helix-Loop-Helix Transcription Factors
  • Pigments, Biological
  • Plant Proteins

Grants and funding

This research was supported by the National High Technology Research and Development Program of China (2013AA102700), the National Natural Science Foundation of China (31401909), and the China Postdoctoral Science Foundation (2014M551758).