Quantitative and qualitative characteristics of cell wall components and prenyl lipids in the leaves of Tilia x euchlora trees growing under salt stress

Abstract

The study was focused on assessing the presence of arabinogalactan proteins (AGPs) and pectins within the cell walls as well as prenyl lipids, sodium and chlorine content in leaves of Tilia x euchlora trees. The leaves that were analyzed were collected from trees with and without signs of damage that were all growing in the same salt stress conditions. The reason for undertaking these investigations was the observations over many years that indicated that there are trees that present a healthy appearance and trees that have visible symptoms of decay in the same habitat. Leaf samples were collected from trees growing in the median strip between roadways that have been intensively salted during the winter season for many years. The sodium content was determined using atomic spectrophotometry, chloride using potentiometric titration and poly-isoprenoids using HPLC/UV. AGPs and pectins were determined using immunohistochemistry methods. The immunohistochemical analysis showed that rhamnogalacturonans I (RG-I) and homogalacturonans were differentially distributed in leaves from healthy trees in contrast to leaves from injured trees. In the case of AGPs, the most visible difference was the presence of the JIM16 epitope. Chemical analyses of sodium and chloride showed that in the leaves from injured trees, the level of these ions was higher than in the leaves from healthy trees. Based on chromatographic analysis, four poly-isoprenoid alcohols were identified in the leaves of T. x euchlora. The levels of these lipids were higher in the leaves from healthy trees. The results suggest that the differences that were detected in the apoplast and symplasm may be part of the defensive strategy of T. x euchlora trees to salt stress, which rely on changes in the chemical composition of the cell wall with respect to the pectic and AGP epitopes and an increased synthesis of prenyl lipids.

Polyprenols Are Synthesized by a Plastidial cis-Prenyltransferase and Influence Photosynthetic Performance

“…This implies that a basal level of polyprenols is required to maintain or stabilize thylakoid membranes under standard plant growth conditions and that any further increases in polyprenol content offer little benefit. However, it is noteworthy that AtCPT7 is highly upregulated in response to various environmental stresses (Zimmermann et al, 2004) and that polyprenols accumulate in such cases (Bajda et al, 2009;Jozwiak et al, 2013;Milewska-Hendel et al, 2017). Given that plastid membranes experience changes in dynamics in response to stress, it is tempting to speculate that the stressinduced accumulation of polyprenols may serve a protective role for plastids in these environments, either as a ballast to support the integrity of thylakoids and/or envelope membranes or as an antioxidant, as recently postulated (Cavallini et al, 2016).…”

Hydroxyproline-Rich Glycoproteins as Markers of Temperature Stress in the Leaves of Brachypodium distachyon

“…Although immunohistochemical analyses are widely used to study changes in the chemical components of the cell wall during different developmental processes, in vivo and in vitro information concerning the presence and distribution of the cell wall proteins in leaves that have been subjected to biotic and/or abiotic stresses are scarce and remain largely unexplored [16,18,25]. Previous studies have primarily focused on the differential expression of AGP in response to temperatures stresses in roots and seedlings; however, the involvement of AGP in the response to temperature stress has rarely been studied in leaves [16].…”

Germline development and seed set of metallophyte Biscutella laevigata L. (Brassicaceae).

“…Immunohistochemical detection of pectin distribution in cell walls of embryo tissues, using primary antibodies for low-and high-esterified homogalacturonan, LM19 and LM20, was preceded according to the protocol of Milewska-Hendel et al (2017). Slides were mounted in a Fluoromount (Sigma-Aldrich) antifade medium.…”