Plants expressing a miR164-resistant CUC2 gene reveal the importance of post-meristematic maintenance of phyllotaxy in Arabidopsis

Development. 2007 Mar;134(6):1045-50. doi: 10.1242/dev.02774. Epub 2007 Jan 24.

Abstract

In plants, the arrangement of organs along the stem (phyllotaxy) follows a predictable pattern. Recent studies have shown that primordium position at the meristem is governed by local auxin gradients, but little is known about the subsequent events leading to the phyllotaxy along the mature stem. We show here that plants expressing a miR164-resistant CUP-SHAPED COTYLEDON2 (CUC2) gene have an abnormal phyllotactic pattern in the fully grown stem, despite the pattern of organ initiation by the meristem being normal. This implies that abnormal phyllotaxy is generated during stem growth. These plants ectopically express CUC2 in the stem, suggesting that the proper timing of CUC2 expression is required to maintain the pattern initiated in the meristem. Furthermore, by carefully comparing the phyllotaxy in the meristem and along the mature inflorescence in wild types, we show that such deviation also occurs during wild-type development, although to a smaller extent. We therefore suggest that the phyllotactic pattern in a fully grown stem results not only from the organogenetic activity of the meristem, but also from the subsequent growth pattern during stem development.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / anatomy & histology
  • Arabidopsis / genetics
  • Arabidopsis / growth & development*
  • Arabidopsis Proteins / genetics*
  • Body Patterning / genetics*
  • Flowers / anatomy & histology
  • Flowers / genetics
  • Flowers / growth & development
  • Gene Expression Regulation, Developmental*
  • Gene Expression Regulation, Plant*
  • Meristem / anatomy & histology
  • Meristem / genetics
  • Meristem / growth & development
  • MicroRNAs / metabolism
  • Mutation
  • Plant Leaves / anatomy & histology
  • Plant Leaves / genetics*
  • Plant Leaves / growth & development
  • RNA, Plant / metabolism

Substances

  • Arabidopsis Proteins
  • CUC2 protein, Arabidopsis
  • MicroRNAs
  • RNA, Plant