Control of phyllotaxy by the cytokinin-inducible response regulator homologue ABPHYL1

Nature. 2004 Aug 26;430(7003):1031-4. doi: 10.1038/nature02778.

Abstract

Phyllotaxy describes the geometric pattern of leaves and flowers, and has intrigued botanists and mathematicians for centuries. How these patterns are initiated is poorly understood, and this is partly due to the paucity of mutants. Signalling by the plant hormone auxin appears to determine the site of leaf initiation; however, this observation does not explain how distinct patterns of phyllotaxy are initiated. abphyl1 (abph1) mutants of maize initiate leaves in a decussate pattern (that is, paired at 180 degrees), in contrast to the alternating or distichous phyllotaxy observed in wild-type maize and other grasses. Here we show that ABPH1 is homologous to two-component response regulators and is induced by the plant hormone cytokinin. ABPH1 is expressed in the embryonic shoot apical meristem, and its spatial expression pattern changes rapidly with cytokinin treatment. We propose that ABPH1 controls phyllotactic patterning by negatively regulating the cytokinin-induced expansion of the shoot meristem, thereby limiting the space available for primordium initiation at the apex.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Alleles
  • Amino Acid Sequence
  • Base Sequence
  • Body Patterning* / drug effects
  • Cytokinins / pharmacology*
  • Gene Expression Regulation, Plant / drug effects*
  • Meristem / anatomy & histology
  • Meristem / drug effects
  • Meristem / growth & development
  • Meristem / metabolism
  • Molecular Sequence Data
  • Mutation / genetics
  • Phenotype
  • Plant Proteins / biosynthesis
  • Plant Proteins / chemistry
  • Plant Proteins / genetics
  • Plant Proteins / metabolism*
  • Plant Shoots / anatomy & histology
  • Plant Shoots / drug effects
  • Plant Shoots / growth & development
  • Plant Shoots / metabolism
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Zea mays / drug effects
  • Zea mays / genetics
  • Zea mays / growth & development*
  • Zea mays / metabolism*

Substances

  • Cytokinins
  • Plant Proteins
  • RNA, Messenger