Composition of suberin-associated waxes from the subterranean storage organs of seven plants

Abstract

The waxes associated with the suberin in the periderm of the underground storage organs of parsnip (Pastinaca sativa L.), carrot (Daucus carota L.), rutabaga (Brassica napobrassica Mill.), turnip (Brassica rapa L.), red beet (Beta vulgaris L.), sweet potato (Ipomoea batatas L.) and potato (Solanum tuberosum L.) were isolated, fractionated into hydrocarbon, wax ester, free fatty alcohol and free fatty acid fractions, and analyzed by combined gas chromatography and mass spectrometry. The amount of wax extracted from the periderm of the storage organs ranged from 2 to 32 μg/cm(2). The hydrocarbons from the suberin layer have a broader chain-length distribution, a predominance of shorter carbon chains, and a higher proportion of even-numbered carbon chains than the leaf alkanes from the same plants. The major components of the free and esterified fatty alcohols and fatty acids have an even number of carbon atoms, and are similar in chain-length distribution to their counterparts found covalently attached to the suberin polymers; however, these suberin components are shorter in chain length than their cuticular analogues from the leaves. Also extracted from the storage organs were polar components which included fatty alcohols and fatty acids in a conjugated form, and ω-hydroxy acids and dicarboxylic acids. Evidence is presented that removal of the wax from the periderm of whole storage organs results in a decrease in diffusion resistance to moisture.

Monoacylglycerols Are Components of Root Waxes and Can Be Produced in the Aerial Cuticle by Ectopic Expression of a Suberin-Associated Acyltransferase

“…2C) was very distinct from that of Arabidopsis aerial parts (Rashotte et al, 2001) and significantly different from that reported for the subterranean storage organs of seven species, including Crucifers (Espelie et al, 1980). In Arabidopsis roots, esters of p-coumaric, caffeic, and ferulic acids with C18-C22 saturated fatty alcohols were the major component (47% [w/w]).…”

“…Unlike cuticular waxes and cutin, suberin waxes tend to reflect, in part, suberin polymer compositions. Suberin-associated waxes have been studied mostly in the native and wound-healing periderm of plant subterranean storage organs, where the main constituents appear to be alkanes, primary alcohols, fatty acids, and alkyl ferulates (Espelie et al, 1980;Bernards and Lewis, 1992;Schreiber et al, 2005). Suberin-associated waxes are considered major contributors to the barrier for water diffusion across suberized cell walls (Soliday et al, 1979), but other factors controlling permeability remain to be identified (Schreiber et al, 2005).…”

Chemical Signals from Avocado Surface Wax Trigger Germination and Appressorium Formation in Colletotrichum gloeosporioides

“…Surface wax from the leaves of the other plants were extracted in a similar manner (Kolattukudy, 1980). Wax from sweet potato periderm was isolated as described before (Espelie et al, 1980). Authentic n-fatty alcohols and acids of even-chain lengths from Cs to C32 were purchased from Analabs (Hamden, CT).…”

Epicuticular Lipid Accumulation on the Leaves of Lycopersicon pennellii (Corr.) D'Arcy and Lycopersicon esculentum Mill

“…Very little has been reported on the epicuticular lipids (defined as those lipids extracted by a brief exposure to organic solvent such as chloroform [3]) found on tomato leaves. Ermakov (2) has assayed the total leaf lipid composition of L. pennellii and L. esculentum cv Gruntovy Gribosvsky.…”