title: The composition of surface wax on trichomes of Arabidopsis thaliana differs from wax on other epidermal cells.
abstract: To protect plants against biotic and abiotic stress, the waxy cuticle must coat all epidermis cells. Here, two independent approaches addressed whether cell-type-specific differences exist between wax compositions on trichomes and other epidermal cells of Arabidopsis thaliana, possibly with different protection roles. First, the total waxes from a mutant lacking trichomes (gl1) were compared to waxes from wild type and a trichome-rich mutant (cpc tcl1 etc1 etc3). In the stem wax, compounds with aliphatic chains longer than 31 carbons (derived from C32precursors) increased in relative abundance in cpc tcl1 etc1 etc3 over gl1. Similarly, the leaf wax from the trichome-rich mutant contained higher amounts of C32+compounds as compared to gl1. Second, leaf trichomes were isolated, and their waxes were analyzed. The wax mixtures of the trichome-rich mutant and the wild type were similar, comprising alkanes and alkenes as well as branched and unbranched primary alcohols. The direct analyses of trichome waxes confirmed that they contained relatively high concentrations of C32+compounds, compared with the pavement cell wax inferred from analysis of gl1 leaves. Finally, the cell-type-specific wax compositions were put into perspective with expression patterns of wax biosynthesis genes in trichomes and pavement cells. Analyses of published transcriptome data (Marks et al., ) revealed that core enzymes involved in elongation of wax precursors to various carbon chain lengths are expressed differentially between epidermis cell types. By combining the chemical and gene expression data, we identified promising gene candidates involved in the formation of C32+aliphatic chains.
authors: Department of Botany, University of British Columbia, 6270 University Boulevard, Vancouver, BC, V6T 1Z4, Canada.
authors: Daniela
authors: D
authors: Hegebarth
authors: Department of Botany, University of British Columbia, 6270 University Boulevard, Vancouver, BC, V6T 1Z4, Canada.
authors: Christopher
authors: C
authors: Buschhaus
authors: Department of Botany, University of British Columbia, 6270 University Boulevard, Vancouver, BC, V6T 1Z4, Canada.
authors: May
authors: M
authors: Wu
authors: Department of Biology, Mount Royal University, 4825 Mount Royal Gate SW, Calgary, AB, T3E 6K6, Canada.
authors: David
authors: D
authors: Bird
authors: Department of Botany, University of British Columbia, 6270 University Boulevard, Vancouver, BC, V6T 1Z4, Canada.|Department of Chemistry, University of British Columbia, 6174 University Boulevard, Vancouver, BC, V6T 1Z3, Canada.
authors: Reinhard
authors: R
authors: Jetter
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant / Q000235:genetics / Q000502:physiology; D019441:Plant Epidermis / Q000235:genetics / Q000378:metabolism; D064201:Trichomes / Q000378:metabolism*; D014885:Waxes / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D014885:Waxes
keywords: 
  Arabidopsis thaliana
  ; cuticle; epidermis; hydrocarbons; pavement cells; trichomes; wax