A comparative study into the chemical constitution of cutins and suberins from Picea abies (L.) Karst., Quercus robur L., and Fagus sylvatica L.

Abstract

The compositions of BF3/CH3OH depolymerisates of cutins and suberins from leaf and periderm samples from Picea abies [L.] Karst., Quercus robur L., and Fagus sylvatica L., respectively, were determined by quantitative capillary gas chromatography/mass spectroscopy. Long-chain monobasic, ω-hydroxymonobasic, dihydroxymonobasic, trihydroxymonobasic and epoxyhydroxymonobasic alkanoic acids constituted the major aliphatic monomers of leaf cutins. The total amounts of cutin monomers ranged from 629 mg · m(-2) (Fagus) to 1350 mg · m(-2) (Quercus). Cutin composition and amounts did not significantly differ between current year and three-year-old needles of Picea. Trans-esterification of periderm samples yielded a much greater variety of aliphatic monomers than obtained from cutins. In addition to the substance classes found with cutins, suberin depolymerisates also contained α, ω-dibasic acids while dihydroxymonobasic acids were lacking. Depolymerisates from periderms taken from different locations on a Picea tree did not differ significantly in their relative composition. The results are discussed in terms of the distinctive characteristics of the aliphatic portions of cutins and suberins, respectively. Discriminant analysis is applied for formulating a quantitative and inarbitrary classification rule for cutins and suberins. The precision, statistical significance and robustness of this classification rule are tested by employing it to a large set of compositional data (70 plant species) from the literature. The relevance of data obtained by depolymerization methods for elucidating the physical structure of cutins and suberins in situ is evaluated.

Glycerol Is a Suberin Monomer. New Experimental Evidence for an Old Hypothesis1

“…Using the discriminant score of Matzke and Riederer (1991) to distinguish suberin and cutin, typical suberins dominate in the seed coat, the chalaza, and the periderm, whereas the nucellar cuticle fraction contains cutin, as expected (bottom of Table I). It can be deduced from these results that the chalazal suberin was not significantly contaminated with nucellar cutin or with suberin from the seed coats, as the predominating chain length of the ␣, -dicarboxylic and -hydroxy fatty acids in the chalazal suberin was C18, whereas in the seed coat and in cotton fibers chain lengths of C22 predominated.…”

“…Comparable amounts of glycerol were also determined in the stem periderm of cotton plants. During the purification of the suberin of the wound-healing periderm of potato tubers, glycerol accumulated at the same rate as ␣, -dicarboxylic fatty acids, the most diagnostic suberin monomers (Matzke and Riederer, 1991). These results suggest that glycerol may be a monomer of suberins in general.…”

“…Glycerol and aromatic and aliphatic suberin and cutin monomers released after acid-catalyzed transesterification of extractive free stem periderm and of three different tissues of seeds of a cotton cultivar with white fibers (St 406) For comparisons, the glycerol content of the wax fraction is also indicated. b Discriminant score D, according to the method of Matzke and Riederer (1991). Negative scores are indicative of cutin and positive scores of suberin.…”

“…rized in Figure 5. Glycerol is present in all four suberin fractions, and its proportion increases at about the same rate as the ␣, -dicarboxylic fatty acids, the most diagnostic suberin monomers (Matzke and Riederer, 1991). In the purified suberin fraction (after dioxane:water extraction), 113 mm glycerol, 244 mm ␣, -dicarboxylic fatty acids, and 97 mm -hydroxy fatty acids were determined per gram dry weight.…”

Identification of an Arabidopsis Feruloyl-Coenzyme A Transferase Required for Suberin Synthesis

“…Monomers released by transesterification include aliphatics such as fatty acids, v-hydroxyfatty acids (OHFAs), a,vdicarboxylic acids (DCAs), and fatty alcohols, often with a significant proportion of very-long-chain saturates ($C20), plus glycerol and p-hydroxycinnamic acids (mainly ferulate; Matzke and Riederer, 1991;Bernards, 2002;Graça and Santos, 2006;Franke and Schreiber, 2007;Pollard et al, 2008). The aromatic network is a hydroxycinnamate-derived polymer, primarily comprised of C-C and ether-linked ferulic acid, N-feruloyltyramine, cinnamic acid, p-coumaric acid, or caffeic acid (Bernards et al, 1995).…”