Meta-analyses of microarrays of Arabidopsis asymmetric leaves1 (as1), as2 and their modifying mutants reveal a critical role for the ETT pathway in stabilization of adaxial-abaxial patterning and cell division during leaf development

Plant Cell Physiol. 2013 Mar;54(3):418-31. doi: 10.1093/pcp/pct027. Epub 2013 Feb 8.

Abstract

It is necessary to use algorithms to analyze gene expression data from DNA microarrays, such as in clustering and machine learning. Previously, we developed the knowledge-based fuzzy adaptive resonance theory (KB-FuzzyART), a clustering algorithm suitable for analyzing gene expression data, to find clues for identifying gene networks. Leaf primordia form around the shoot apical meristem (SAM), which consists of indeterminate stem cells. Upon initiation of leaf development, adaxial-abaxial patterning is crucial for lateral expansion, via cellular proliferation, and the formation of flat symmetric leaves. Many regulatory genes that specify such patterning have been identified. Analysis by the KB-FuzzyART and subsequent molecular and genetic analyses previously showed that ASYMMETRIC LEAVES1 (AS1) and AS2 repress the expression of some abaxial-determinant genes, such as AUXIN RESPONSE FACTOR3 (ARF3)/ETTIN (ETT) and ARF4, which are responsible for defects in leaf adaxial-abaxial polarity in as1 and as2. In the present study, genetic analysis revealed that ARF3/ETT and ARF4 were regulated by modifier genes, BOBBER1 (BOB1) and ELONGATA3 (ELO3), together with AS1-AS2. We analyzed expression arrays with as2 elo3 and as2 bob1, and extracted genes downstream of ARF3/ETT by using KB-FuzzyART and molecular analyses. The results showed that expression of Kip-related protein (KRP) (for inhibitors of cyclin-dependent protein kinases) and Isopentenyltransferase (IPT) (for biosynthesis of cytokinin) genes were controlled by AS1-AS2 through ARF3/ETT and ARF4 functions, which suggests that the AS1-AS2-ETT pathway plays a critical role in controlling the cell division cycle and the biosynthesis of cytokinin around SAM to stabilize leaf development in Arabidopsis thaliana.

Publication types

  • Meta-Analysis
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Algorithms
  • Alkyl and Aryl Transferases / genetics
  • Alkyl and Aryl Transferases / metabolism
  • Arabidopsis / genetics*
  • Arabidopsis / growth & development
  • Arabidopsis / physiology
  • Arabidopsis Proteins / genetics*
  • Arabidopsis Proteins / metabolism
  • Cell Division
  • Cluster Analysis
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism
  • Gene Expression Profiling
  • Gene Expression Regulation, Plant*
  • Indoleacetic Acids / metabolism
  • Meristem / genetics
  • Meristem / growth & development
  • Meristem / physiology
  • Models, Molecular
  • Mutation
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism
  • Oligonucleotide Array Sequence Analysis
  • Phenotype
  • Plant Growth Regulators / metabolism
  • Plant Leaves / genetics*
  • Plant Leaves / growth & development
  • Plant Leaves / physiology
  • Plant Shoots / genetics
  • Plant Shoots / growth & development
  • Plant Shoots / physiology
  • Transcription Factors / genetics
  • Transcription Factors / metabolism

Substances

  • ARF4 protein, Arabidopsis
  • AS2 protein, Arabidopsis
  • ASYMMETRIC LEAVES1 protein, Arabidopsis
  • Arabidopsis Proteins
  • DNA-Binding Proteins
  • ETT protein, Arabidopsis
  • Indoleacetic Acids
  • Nuclear Proteins
  • Plant Growth Regulators
  • Transcription Factors
  • Alkyl and Aryl Transferases
  • adenylate isopentenyltransferase