Planta

, Volume 222, Issue 3, pp 472–483

Cuticular wax deposition in growing barley (Hordeum vulgare) leaves commences in relation to the point of emergence of epidermal cells from the sheaths of older leaves

  • Andrew Richardson
  • Rochus Franke
  • Gerhard Kerstiens
  • Mike Jarvis
  • Lukas Schreiber
  • Wieland Fricke
Original Article

DOI: 10.1007/s00425-005-1552-2

Cite this article as:
Richardson, A., Franke, R., Kerstiens, G. et al. Planta (2005) 222: 472. doi:10.1007/s00425-005-1552-2

Abstract

In grasses, leaf cells divide and expand within the sheaths of older leaves, where the micro-environment differs from the open atmosphere. By the time epidermal cells are displaced into the atmosphere, they must have a functional cuticle to minimize uncontrolled water loss. In the present study, gas chromatography and scanning electron microscopy were used to follow cuticular wax deposition along the growing leaf three of barley (Hordeum vulgare L.). 1-Hexacosanol (C26 alcohol) comprised more than 75% of extractable cuticular wax and was used as a marker for wax deposition. There was no detectable wax along the first 20 mm from the point of leaf insertion. Deposition started within the distal portion of the elongation zone (23–45 mm) and continued beyond the point of leaf emergence from the sheath of leaf two. The region where wax deposition commenced shifted towards more proximal (basal) positions when the point of leaf emergence was lowered by stripping back part of the sheath. When relative humidity in the shoot environment was elevated from 70% (standard growth conditions) to 92–96% for up to 4  days prior to analysis, wax deposition did not change significantly. The results show that cuticular waxes are deposited along the growing grass leaf independent of cell age or developmental stage. Instead, the reference point for wax deposition appears to be the point of emergence of cells into the atmosphere. The possibility of changes in relative humidity between enclosed and emerged leaf regions triggering wax deposition is discussed.

Keywords

Cell developmentCuticleHordeumLeaf growthRelative humidityWax

Abbreviations

FID

Flame ionization detector

GC

Gas chromatography

LEV

Leaf elongation velocity

MS

Mass spectrometry

POE

Point of emergence

REGR

Relative elemental growth rate

RH

Relative humidity

SEM

Scanning electron microscopy

Copyright information

© Springer-Verlag 2005

Authors and Affiliations

  • Andrew Richardson
    • 1
  • Rochus Franke
    • 2
  • Gerhard Kerstiens
    • 3
  • Mike Jarvis
    • 4
  • Lukas Schreiber
    • 2
  • Wieland Fricke
    • 1
  1. 1.Division of Biological SciencesUniversity of PaisleyPaisleyUK
  2. 2.Department of Ecophysiology, IZMBUniversity of BonnBonnGermany
  3. 3.Lancaster Environment Centre, Department of Biological SciencesLancaster UniversityLancasterUK
  4. 4.Department of ChemistryUniversity of GlasgowGlasgowUK