Functional roles of three cutin biosynthetic acyltransferases in cytokinin responses and skotomorphogenesis

PLoS One. 2015 Mar 24;10(3):e0121943. doi: 10.1371/journal.pone.0121943. eCollection 2015.

Abstract

Cytokinins (CKs) regulate plant development and growth via a two-component signaling pathway. By forward genetic screening, we isolated an Arabidopsis mutant named grow fast on cytokinins 1 (gfc1), whose seedlings grew larger aerial parts on MS medium with CK. gfc1 is allelic to a previously reported cutin mutant defective in cuticular ridges (dcr). GFC1/DCR encodes a soluble BAHD acyltransferase (a name based on the first four enzymes characterized in this family: Benzylalcohol O-acetyltransferase, Anthocyanin O-hydroxycinnamoyltransferase, anthranilate N-hydroxycinnamoyl/benzoyltransferase and Deacetylvindoline 4-O-acetyltransferase) with diacylglycerol acyltransferase (DGAT) activity in vitro and is necessary for normal cuticle formation on epidermis in vivo. Here we show that gfc1 was a CK-insensitive mutant, as revealed by its low regeneration frequency in vitro and resistance to CK in adventitious root formation and dark-grown hypocotyl inhibition assays. In addition, gfc1 had de-etiolated phenotypes in darkness and was therefore defective in skotomorphogenesis. The background expression levels of most type-A Arabidopsis Response Regulator (ARR) genes were higher in the gfc1 mutant. The gfc1-associated phenotypes were also observed in the cutin-deficient glycerol-3-phosphate acyltransferase 4/8 (gpat4/8) double mutant [defective in glycerol-3-phosphate (G3P) acyltransferase enzymes GPAT4 and GPAT8, which redundantly catalyze the acylation of G3P by hydroxyl fatty acid (OH-FA)], but not in the cutin-deficient mutant cytochrome p450, family 86, subfamily A, polypeptide 2/aberrant induction of type three 1 (cyp86A2/att1), which affects the biosynthesis of some OH-FAs. Our results indicate that some acyltransferases associated with cutin formation are involved in CK responses and skotomorphogenesis in Arabidopsis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acyltransferases / genetics
  • Acyltransferases / metabolism*
  • Arabidopsis / genetics
  • Arabidopsis / growth & development*
  • Arabidopsis / metabolism*
  • Arabidopsis / radiation effects
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism
  • Cytokinins / metabolism*
  • Cytokinins / pharmacology
  • Darkness
  • Gene Expression Regulation, Plant / drug effects
  • Gene Expression Regulation, Plant / radiation effects
  • Membrane Lipids / biosynthesis*
  • Meristem / drug effects
  • Meristem / genetics
  • Meristem / growth & development
  • Meristem / radiation effects
  • Morphogenesis* / drug effects
  • Morphogenesis* / radiation effects
  • Mutation
  • Phenotype
  • Seedlings / drug effects
  • Seedlings / genetics
  • Seedlings / growth & development
  • Seedlings / radiation effects

Substances

  • Arabidopsis Proteins
  • Cytokinins
  • Membrane Lipids
  • cutin
  • Acyltransferases

Grants and funding

This work was supported by grants from the Chinese National Science Foundation (31371431 and 31030045) and the Czech Ministry of Education grant from the National Program for Sustainability I (LO1204). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.