Journal article

Synergistic interaction of the two paralogous Arabidopsis genes LRX1 and LRX2 in cell wall formation during root hair development

  • Baumberger, N. Institute of Plant Biology, University of Zürich, Switzerland
  • Steiner, M. Institute of Plant Biology, University of Zürich, Switzerland
  • Ryser, Ulrich Institute of Plant Biology, University of Fribourg, Switzerland
  • Keller, B. Institute of Plant Biology, University of Zürich, Switzerland
  • Ringli, C. Institute of Plant Biology, University of Zürich, Switzerland
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    2003
Published in:
  • The Plant Journal. - 2003, vol. 35(1), no. 71
LRR-extensins (LRX) form a family of structural cell wall proteins containing a receptor-like domain. The functional analysis of <i>Arabidopsis LRX1</i> has shown that it is involved in cell morphogenesis of root hairs. In this work, we have studied <i>LRX2</i>, a paralog of <i>LRX1</i>. <i>LRX2</i> expression is mainly found in roots and is responsive to factors promoting or repressing root hair formation. The function of <i>LRX1</i> and <i>LRX2</i> was tested by the expression of a truncated LRX2 and different LRX1/LRX2 chimaeric proteins. Using complementation of the <i>lrx1</i> phenotype as the parameter for protein function, our experiments indicate that LRX1 and LRX2 are functionally similar but show differences in their activity. Genetic analysis revealed that single <i>lrx2</i> mutants do not show any defect in root hair morphogenesis, but synergistically interact with the <i>lrx1</i> mutation. <i>lrx1/lrx2</i> double mutants have a significantly enhanced <i>lrx1</i> phenotype, resulting in frequent rupture of the root hairs soon after their initiation. Analysis of the root hair cell wall ultrastructure by transmission electron microscopy (TEM) revealed the formation of osmophilic aggregates within the wall, as well as local disintegration of the wall structure in the double mutant, but not in wild-type plants. Our results indicate that LRX1 and LRX2 have overlapping functions in root hair formation, and that they likely regulate cell morphogenesis by promoting proper development of the cell wall.
Faculty
Faculté des sciences
Department
Biologie
Language
  • English
Classification
Biology
License
License undefined
Identifiers
Persistent URL
https://folia.unifr.ch/unifr/documents/299873