Phellem Cell-Wall Components Are Discriminants of Cork Quality in Quercus suber

Author(s)
Carla Pinheiro, Stefanie Wienkoop, João Feio de Almeida, Cecilia Brunetti, Olfa Zarrouk, Sébastien Planchon, Antonella Gori, Massimiliano Tattini, Cândido Pinto Ricardo, Jenny Renaut, Rita Teresa Teixeira
Abstract

Cork is a renewable, non-wood high valued forest product, with relevant ecological and economic impact in the Mediterranean-type ecosystems. Currently, cork is ranked according to its commercial quality. The most valuable planks are chosen for cork stoppers production. Cork planks with adequate thickness and porosity are classified as stoppable quality cork (SQC). The chemical composition of cork is known, but the regulation of metabolic pathways responsible of cork production and composition, hence of cork quality, is largely unknown. Here, we tested the hypothesis that post-genomic events may be responsible for the development of SQC and N-SQC (non-stoppable quality cork). Here, we show that combined proteomics and targeted metabolomics (namely soluble and cell wall bound phenolics) analyzed on recently formed phellem allows discriminate cork planks of different quality. Phellem cells of SQC and N-SQC displayed different reducing capacity, with consequential impact on both enzymatic pathways (e.g., glycolysis) and other cellular functions, including cell wall assembly and suberization. Glycolysis and respiration related proteins were abundant in both cork quality groups, whereas the level of several proteins associated to mitochondrial metabolism was higher in N-SQC. The soluble and cell wall-bound phenolics in recently formed phellem clearly discriminated SQC from N-SCQ. In our study, SQC was characterized by a high incorporation of aromatic components of the phenylpropanoid pathway in the cell wall, together with a lower content of hydrolysable tannins. Here, we propose that the level of hydrolysable tannins may represent a valuable diagnostic tool for screening recently formed phellem, and used as a proxy for the quality grade of cork plank produced by each tree.

Organisation(s)
Functional and Evolutionary Ecology, Department of Ecogenomics and Systems Biology
External organisation(s)
Universidade Nova de Lisboa, National Research Council of Italy (CNR), Università degli Studi di Firenze, Luxembourg Institute of Science and Technology, Universidade de Lisboa
Journal
Frontiers in Plant Science
Volume
10
ISSN
1664-462X
DOI
https://doi.org/10.3389/fpls.2019.00944
Publication date
07-2019
Peer reviewed
Yes
Austrian Fields of Science 2012
Plant physiology, Proteomics, Metabolomics , Biochemistry
Keywords
ASJC Scopus subject areas
Portal url
https://ucris.univie.ac.at/portal/en/publications/phellem-cellwall-components-are-discriminants-of-cork-quality-in-quercus-suber(3ea76c95-9f48-4ef6-bcc9-5eb2d7b3933c).html