Synthesis of Suberin during Wound-healing in Jade Leaves, Tomato Fruit, and Bean Pods

Abstract

The structure and composition of the aliphatic monomers of the polymeric material deposited during wound-healing of tomato fruit, bean pods, and Jade leaves were examined. After removing the cuticlecontaining layer of tissue, the wounds were healed for 14 days and the resulting surface layer was excised, lyophilized, solvent-extracted, and depolymerized by hydrogenolysis with LiAIH4 or transesterified with BF3 in methanol. The products obtained by the chemical depolymerization were subjected to thin layer chromatography and combined gas chromatography and mass spectrometry. The major aliphatic components isolated from the hydrogenolysate of the wound polymer produced by tomato fruit were hexadecane-1,16-diol and octadec-9-ene-1,18-diol, which were shown to be derived from a 1:1 mixture of w-hydroxy and dicarboxylic acids of the appropriate chain length by LiAIH4 reduction.Also identified in the wound polymer were long chain (>C20) fatty acids and alcohols. This monomer composition is typical of suberin polymers and is in sharp contrast with that of the cutin of tomato fruit which contains dihydroxy C16 add as the major aliphatic component. The hydrogenolysis of the wound material from bean pods gave octadecene-1,18-diol as the major aliphatic component, and smaller amounts of hexadecane-1,16-diol and long chain alcohols. Similar treatment of the normal cuticular tissue of these pods gave hexadecane triol, as well as C16 and C18 alcohols. Hydrogenolysis of wound material from the Jade leaves gave octadecene-1,18-diol, C16 and C22 diols, as well as alcohols from C16 to C26, whereas similar treatment of the cutin-containing tissue from these leaves gave C16 triol as the major aliphatic component. Thus, the major aliphatic monomers of the polymeric material deposited during the wound-healing of bean pods and Jade leaves are very similar to those of suberin, although the natural protective polymer of these tissues is cutin. From these results, it is concluded that suberization is a fundamental process involved in wound-healing in plants, irrespective of the chemical nature of the natural protective polymer of the tissue.In recent years, the composition of the monomers of cutin and suberin, the lipid polymers which cover plants, has been studied with modern analytical techniques. The major components of cutin are dihydroxy C16 fatty acids, 18-hydroxy-9,10-epoxy C18 fatty acids, and trihydroxy C18 fatty acids. Also found are smaller amounts of w-hydroxy C16 and C18 fatty acids. The major aliphatic components of suberin are w-hydroxy fatty acids and dicarboxylic acids from C16 to C28 and fatty acids and alcohols in which aliphatic chains longer than C20 often predominate (4,6,7,10,13,17). The composition of the aliphatic monomers of the '

Characterization of an Arabidopsis cDNA for a soluble epoxide hydrolase gene that is inducible by auxin and water stress

“…Furthermore, the aerial parts of plants are covered by cuticles which consists of cutin embedded in waxes, while the underground organs are protected by suberins (Kolattukudy, 1984). Suberin is also attached to the cell wall of wound periderms formed on the aerial parts and of connection between the seed coats and vascular tissues (Dean and Kolattukudy, 1976;Espelie et aL, 1980;Kolattukudy, 1984). The AtsEH mRNAs were detected in leaves and stems but not in roots, flowers or seeds of aged plants.…”

MYB107 and MYB9 Homologs Regulate Suberin Deposition in Angiosperms

“…While control of water movement can be considered the principal role of the cuticle, additional roles include structural support and protection against pathogen infection and herbivory Chen et al, 2011a). In the event of wounding or damage to the surface, the plant produces suberin (Dean and Kolattukudy, 1976). This polymer is analogous to cutin, but consists of slightly longer chain length fatty acids as well as a polyphenol domain (predominantly ferulic esters) Schreiber, 2010;Beisson et al, 2012).…”

Abiotic Stress in Harvested Fruits and Vegetables

“…This up-regulation of PAL was associated with wound-induced ethylene production. Other metabolites increase in response to bruising or wounding stress, including isocoumarin in carrots (Lafuente et al, 1996), anthocyanins in midribs of redpigmented lettuce (Ferreres et al, 1997), methanethiol, allyl isothiocyanates and dimethyl disulfide in cabbage (Yano et al, 1986;Chin and Lindsay, 1993), six-carbon aldehydes and alcohols in cut peppers (Wu and Liou, 1986) and suberin in tomatoes and bean pods (Dean and Kolattukudy, 1976). Some of the metabolic shifts are mediated by stress response messengers (e.g.…”