A comparison of suberin monomers from the multiseriate exodermis of Iris germanica during maturation under differing growth conditions

Abstract

Iris germanica roots develop a multiseriate exodermis (MEX) in which all mature cells contain suberin lamellae. The location and lipophilic nature of the lamellae contribute to their function in restricting radial water and solute transport. The objective of the current work was to identify and quantify aliphatic suberin monomers, both soluble and insoluble, at specific stages of MEX development and under differing growth conditions, to better understand aliphatic suberin biosynthesis. Roots were grown submerged in hydroponic culture, wherein the maturation of up to three exodermal layers occurred over 21 days. In contrast, when roots were exposed to a humid air gap, MEX maturation was accelerated, occurring within 14 days. The soluble suberin fraction included fatty acids, alkanes, fatty alcohols, and ferulic acid, while the suberin poly(aliphatic) domain (SPAD) included fatty acids, α,ω-dioic acids, ω-OH fatty acids, and ferulic acid. In submerged roots, SPAD deposition increased with each layer, although the composition remained relatively constant, while the composition of soluble components shifted toward increasing alkanes in the innermost layers. Air gap exposure resulted in two significant shifts in suberin composition: nearly double the amount of SPAD monomers across all layers, and almost three times the alkane accumulation in the first layer. The localized and abundant deposition of C18:1 α,ω-dioic and ω-OH fatty acids, along with high accumulation of intercalated alkanes in the first mature exodermal layer of air gap-exposed roots indicate its importance for water retention under drought compared with underlying layers and with entire layers developing under water.

Differential induction of polar and non‐polar metabolism during wound‐induced suberization in potato (Solanum tuberosum L.) tubers

“…Extractive-free residues were dried at room temperature and weighed into sub-samples ranging from 5 to 15 mg of tissue. Soluble extractives and extractive-free residues were prepared for gas chromatography (GC) analysis as described (Meyer et al, 2011).…”

Response of Fruit Bagging to Lignin Biosynthesis and Expression of Related Genes in Fruit Peel of Sand Pear (Pyrus pyrifolia Nakai) cv. Cuiguan

“…The suberification process is closely related to lignin and phenolic concentrations (Bernards, 2002;Grac xa and Santos, 2007), and it has been reported that lignin, cellulose, and hemicellulose contents are higher in russet peel than in green peel (Heng et al, 2014;Shi et al, 2019). Suberin is a macromolecular structure composed of the suberin poly-phenolic domain (SPPD) and the suberin polyaliphatic domain (SPAD), which are covalently linked by hydroxyferulic acid and its derivatives in a lignin-like manner (Meyer et al, 2011a(Meyer et al, , 2011b. Lignin, a primary component of plant cell walls, is an abundant natural polymer that is based on phenylpropane derivatives, and its biosynthesis has been shown to be closely associated with russeting in sand pear (Lu et al, 2015).…”

Root morphophysiology changes during the habitat transition from soil to canopy of the aroid vine Rhodospatha oblongata

“…This gradual loss of peripheral tissues exposes the second DTB and the green aerial root phase. The loss of peripheral root tissue in angiosperms may be limited to the epidermis, making the exodermis a superficial tissue (Yang et al, 2014), although in some cases it may occur internally, leading to partial (Stevens et al, 1997;Meyer et al, 2011) or even total loss of the cortex, when the endoderm is kept as the coating tissue (Kauff et al, 2000). Such tissue losses are usually caused by the increase in diameter (Šottníková and Lux, 2003) or by the development of a more resistant tissue in the inner part of the cortex, induced by drought (North and Nobel, 1995) or hypoxia.…”