The Cell Wall Proteome of Marchantia polymorpha Reveals Specificities Compared to Those of Flowering Plants.

Hasan Kolkas,Elisabeth Jamet,Josiane Chourré,Michel Zivy,Thierry Balliau,Hervé Canut

doi:10.3389/fpls.2021.765846

Abstract

Primary plant cell walls are composite extracellular structures composed of three major classes of polysaccharides (pectins, hemicelluloses, and cellulose) and of proteins. The cell wall proteins (CWPs) play multiple roles during plant development and in response to environmental stresses by remodeling the polysaccharide and protein networks and acting in signaling processes. To date, the cell wall proteome has been mostly described in flowering plants and has revealed the diversity of the CWP families. In this article, we describe the cell wall proteome of an early divergent plant, Marchantia polymorpha, a Bryophyte which belong to one of the first plant species colonizing lands. It has been possible to identify 410 different CWPs from three development stages of the haploid gametophyte and they could be classified in the same functional classes as the CWPs of flowering plants. This result underlied the ability of M. polymorpha to sustain cell wall dynamics. However, some specificities of the M. polymorpha cell wall proteome could be highlighted, in particular the importance of oxido-reductases such as class III peroxidases and polyphenol oxidases, D-mannose binding lectins, and dirigent-like proteins. These proteins families could be related to the presence of specific compounds in the M. polymorpha cell walls, like mannans or phenolics. This work paves the way for functional studies to unravel the role of CWPs during M. polymorpha development and in response to environmental cues.

Highlights

Plant cell walls are composite structures made of polysaccharidic polymers like pectins, hemicelluloses and cellulose as well as of lignins in lignified secondary walls (Carpita and Gibeaut, 1993; Vanholme et al, 2019)
The same cell wall proteins (CWPs) families could be identified in all the cell wall proteomes described so far1 and could be grouped in functional classes according to the presence of predicted functional domains and experimental work (Jamet et al, 2008): proteins acting on carbohydrates (PAC), oxidoreductases (OR), proteases (P), proteins possibly related to lipid metabolism (LM), proteins with interaction domains with polysaccharides or proteins (ID), proteins possibly involved in signaling (S), structural proteins (SP), miscellaneous proteins (M), and proteins of yet unknown function (UF)
The risk was to favor their unspecific oxidative fixation on proteins and to prevent the proper extraction and the identification of proteins by MS and bioinformatics. We have quantified these compounds at the three different stages of development of M. polymorpha of interest (Figure 1): 2 week-old thalli undergoing active growth and exhibiting scarce rhizoids, 3 week-old thalli representing an intermediate stage of development with more rhizoids, and 5 week-old thalli carrying gemma cups

Summary

Introduction

Plant cell walls are composite structures made of polysaccharidic polymers like pectins, hemicelluloses and cellulose as well as of lignins in lignified secondary walls (Carpita and Gibeaut, 1993; Vanholme et al, 2019). Present in lower amount, cell wall proteins (CWPs) play critical roles in polymer remodeling and in signaling during plant development and in response to environmental clues (Franková and Fry, 2013; Le Gall et al, 2015; Cosgrove, 2016; Novakovicet al., 2018). The same CWP families could be identified in all the cell wall proteomes described so far (see WallProtDB) and could be grouped in functional classes according to the presence of predicted functional domains and experimental work (Jamet et al, 2008): proteins acting on carbohydrates (PAC), oxidoreductases (OR), proteases (P), proteins possibly related to lipid metabolism (LM), proteins with interaction domains with polysaccharides or proteins (ID), proteins possibly involved in signaling (S), structural proteins (SP), miscellaneous proteins (M), and proteins of yet unknown function (UF)

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