Suberized transport barriers in Arabidopsis, barley and rice roots: From the model plant to crop species

Abstract

Water is the most important prerequisite for life and plays a major role during uptake and transport of nutrients. Roots are the plant organs that take up the major part of water, from the surrounding soil. Water uptake is related to the root system architecture, root growth, age and species dependent complex developmental changes in the anatomical structures. The latter is mainly attributed to the deposition of suberized barriers in certain layers of cell walls, such as endo- and exodermis. With respect to water permeability, changes in the suberization of roots are most relevant. Water transport or hydraulic conductivity of roots (Lp) can be described by the composite transport model and is known to be very variable between plant species and growth conditions and root developmental states. In this review, we summarize how anatomical structures and apoplastic barriers of roots can diversely affect water transport, comparing the model plant Arabidopsis with crop plants, such as barley and rice. Results comparing the suberin amounts and water transport properties indicate that the common assumption that suberin amount negatively correlates with water and solute transport through roots may not always be true. The composition, microstructure and localization of suberin may also have a great impact on the formation of efficient barriers to water and solutes.

Osmotic stress enhances suberization of apoplastic barriers in barley seminal roots: analysis of chemical, transcriptomic and physiological responses

“…Detailed knowledge of the anatomy of the developmental stages along the root was important for our further analyses, including chemical, transcriptomic and water transport measurements and their interpretations (Steudle & Peterson, ; Steudle, 2000b; Kreszies et al ., ). The suberin lamellae were only visible in the endodermis and we detected no exodermis, not even under the most severe osmotic stress conditions (−1.2 MPa) applied.…”

“…Putative barley orthologs of suberin, lignin, fatty acid elongation and aquaporin genes are based on known mutants described in Arabidopsis and rice (Fraser & Chapple, 2011;Ranathunge et al, 2011b;Li-Beisson et al, 2013;Vishwanath et al, 2015;Kreszies et al, 2018). The barley genes were retrieved via the IPK Barley BLAST server (Deng et al, 2007) and the orthologous search from ENSEMBLPLANTS (Kersey et al, 2016).…”

“…Caution should be exercised when transferring results obtained from Arabidopsis to other plant species, including crop plants. Such simple and direct one-to-one correlations may not always be valid (Kreszies et al, 2018). However, future experimental approaches with higher resolution, allowing, for example, the direct analysis of the chemical composition of Casparian bands of Arabidopsis roots, might help to answer this question.…”

The Intensity of Manganese Deficiency Strongly Affects Root Endodermal Suberization and Ion Homeostasis

“…Cell wall suberization markedly reduces the hydraulic conductivity of the apoplastic pathway, whereas the cell-to-cell pathway is unaltered. Upon sealing of the apoplast in the fully suberized root zone, uncontrolled back-flow of water is strongly reduced (Kreszies et al, 2018).…”

Seminal roots of wild and cultivated barley differentially respond to osmotic stress in gene expression, suberization, and hydraulic conductivity

“…Symplastic and transcellular pathways are often referred together as the cell-tocell pathway. Resistances of these pathways can be regulated and modified by suberin deposition and plasma membrane-bound aquaporins (Kim et al, 2018;Kreszies, Schreiber, & Ranathunge, 2018;Steudle, 2000aSteudle, , 2000bSteudle & Peterson, 1998). The hydrophobic biopolyester suberin is the main component of apoplastic barriers of roots, and it plays a significant role in water and nutrient transport (Franke & Schreiber, 2007;Ranathunge, Schreiber, & Franke, 2011).…”