Elevated levels of MYB30 in the phloem accelerate flowering in Arabidopsis through the regulation of FLOWERING LOCUS T

PLoS One. 2014 Feb 25;9(2):e89799. doi: 10.1371/journal.pone.0089799. eCollection 2014.

Abstract

In Arabidopsis thaliana, the R2R3 MYB-like transcription factor MYB30 is a positive regulator of the pathogen-induced hypersensitive response and of brassinosteroid and abscisic acid signaling. Here, we show that MYB30 expressed under the control of the strong phloem-specific SUC2 promoter accelerates flowering both in long and short days. Early flowering is mediated by elevated expression of flowering locus T (FT), which can be observed in the absence and presence of CONSTANS (CO), the main activator of FT. CO-independent activation by high MYB30 expression results in FT levels that remain below those observed in the wild-type plants, which show an additive CO-dependent activation. In contrast, twin sister of FT (TSF) is repressed in plants expressing high levels of MYB30 in the phloem. In transient assays, MYB30 and CO additively increase the activity of a reporter construct driven by a 1 kb FT promoter. Acceleration of flowering by MYB30 does not require the presence of salicylic acid and is independent of FLC. Taken together, increased levels of MYB30, which was reported to be induced in response to the perception of pathogens, can accelerate flowering and MYB30 may thus be a candidate to mediate cross-talk between gene networks involved in biotic stress perception and flowering time.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / metabolism
  • Arabidopsis / physiology*
  • Arabidopsis Proteins / metabolism*
  • Flowers / genetics
  • Flowers / physiology*
  • Gene Expression Regulation, Plant / physiology*
  • Phloem / metabolism*
  • Plants, Genetically Modified
  • Reverse Transcriptase Polymerase Chain Reaction
  • Signal Transduction / genetics
  • Signal Transduction / physiology
  • Stress, Physiological / genetics
  • Transcription Factors / metabolism*

Substances

  • Arabidopsis Proteins
  • FT protein, Arabidopsis
  • MYB30 protein, Arabidopsis
  • Transcription Factors

Grant support

The authors thank the Chinese Academy of Sciences (CAS) and the Max Planck Society (MPS) for funding. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.