title: Low secondary leaf wax n-alkane synthesis on fully mature leaves of C3 grasses grown at controlled environmental conditions and variable humidity.
abstract: BACKGROUND
  Leaf wax n-alkanes are long-chained aliphatic compounds that are present in the cuticle of terrestrial plant leaves. Their δ2H values are used for the reconstruction of past environments and for plant ecological investigations. The timing of n-alkane synthesis during leaf development and the rate of synthesis of secondary n-alkanes in fully matured leaves are still a matter of debate.
  
  
  METHODS
  Using a2H-labeling approach we estimated secondary leaf wax n-alkane synthesis rates in mature leaf blades of six C3 grass species grown in climate chambers under controlled environmental conditions.
  
  
  RESULTS
  We found that mature grass leaves continue the synthesis of leaf wax n-alkanes after leaf maturation. The rate of secondary n-alkanes synthesis was, however, relatively low and varied in response to atmospheric humidity and among species from 0.09 to 1.09% per day.
  
  
  CONCLUSIONS
  Our investigation provides new evidence on the timing of cuticular wax synthesis in grass leaves and indicates that the majority of n-alkanes are synthesized during the initial development of the leaf. Our study will improve the interpretation of leaf wax n-alkane δ2H values in environmental and geological studies as it suggests that secondary synthesis of leaf wax n-alkanes in grass leaves contributes only slightly to the geological record. Copyright © 2016 John Wiley & Sons, Ltd.
authors: Department of Environmental Systems Sciences, ETH Zürich, Switzerland.|Department of Environmental Sciences - Botany, University of Basel, Switzerland.
authors: Bruno
authors: B
authors: Gamarra
authors: Department of Environmental Sciences - Botany, University of Basel, Switzerland.
authors: Ansgar
authors: A
authors: Kahmen
mesh_terms: D000473:Alkanes / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism*; D003903:Deuterium / Q000032:analysis / Q000378:metabolism; D008401:Gas Chromatography-Mass Spectrometry; D006813:Humidity; D018515:Plant Leaves / Q000737:chemistry / Q000378:metabolism*; D006109:Poaceae / Q000737:chemistry / Q000378:metabolism*; D014885:Waxes / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism*
chemical_list: D000473:Alkanes; D014885:Waxes; D003903:Deuterium