Plant Molecular Biology

, Volume 42, Issue 1, pp 151–166

Knots in the family tree: evolutionary relationships and functions of knox homeobox genes

  • Leonore Reiser
  • Patricia Sánchez-Baracaldo
  • Sarah Hake
Article

DOI: 10.1023/A:1006384122567

Cite this article as:
Reiser, L., Sánchez-Baracaldo, P. & Hake, S. Plant Mol Biol (2000) 42: 151. doi:10.1023/A:1006384122567

Abstract

Knotted-like homeobox (knox) genes constitute a gene family in plants. Class I knox genes are expressed in shoot apical meristems, and (with notable exceptions) not in lateral organ primordia. Class II genes have more diverse expression patterns. Loss and gain of function mutations indicate that knox genes are important regulators of meristem function. Gene duplication has contributed to the evolution of families of homeodomain proteins in metazoans. We believe that similar mechanisms have contributed to the diversity of knox gene function in plants. Knox genes may have contributed to the evolution of compound leaves in tomato and could be involved in the evolution of morphological traits in other species. Alterations in cis-regulatory regions in some knox genes correlate with novel patterns of gene expression and distinctive morphologies. Preliminary data from the analysis of class I knox gene expression illustrates the evolution of complex patterns of knox expression is likely to have occurred through loss and gain of domains of gene expression.

evolutionhomeodomain proteinknox genemeristem

Copyright information

© Kluwer Academic Publishers 2000

Authors and Affiliations

  • Leonore Reiser
    • 1
  • Patricia Sánchez-Baracaldo
    • 2
  • Sarah Hake
    • 1
  1. 1.Department of Plant and Microbial BiologyUniversity of CaliforniaBerkeleyUSA
  2. 2.Department of Integrative Biology and University and Jepson HerbariaUniversity of CaliforniaBerkeleyUSA