Emerging Functions for Cell Wall Polysaccharides Accumulated during Eudicot Seed Development

Abstract

The formation of seeds is a reproductive strategy in higher plants that enables the dispersal of offspring through time and space. Eudicot seeds comprise three main components, the embryo, the endosperm and the seed coat, where the coordinated development of each is important for the correct formation of the mature seed. In addition, the seed coat protects the quiescent progeny and can provide transport mechanisms. A key underlying process in the production of seed tissues is the formation of an extracellular matrix termed the cell wall, which is well known for its essential function in cytokinesis, directional growth and morphogenesis. The cell wall is composed of a macromolecular network of polymers where the major component is polysaccharides. The attributes of polysaccharides differ with their composition and charge, which enables dynamic remodeling of the mechanical and physical properties of the matrix by adjusting their production, modification or turnover. Accordingly, the importance of specific polysaccharides or modifications is increasingly being associated with specialized functions within seed tissues, often through the spatio-temporal accumulation or remodeling of particular polymers. Here, we review the evolution and accumulation of polysaccharides during eudicot seed development, what is known of their impact on wall architecture and the diverse roles associated with these in different seed tissues.

Sticky mucilages and exudates of plants: putative microenvironmental design elements with biotechnological value

“…The molecular mechanisms of mucilage secretion have been mainly investigated using the Arabidopsis seed coat as a model, where special secretory cells are used to produce and exude the mucilage components (Sechet et al, 2018). Polysaccharides are formed either through monosaccharide cytosolic synthesis or within the Golgi apparatus by glycosyl-transferase enzymes (Voiniciuc et al, 2018).…”

“…Some molecules within mucilages have bioadhesive properties, making them sought-after materials for biotechnological, biomedical or agricultural applications (Favi et al, 2014;George & Suchitra, 2019). Important breakthroughs have been made in the last few years in investigations of the sticky adhesives used by English ivy and by sundew (Zhang et al, 2010;Lenaghan & Zhang, 2012), and a current focus on molecular genetic investigations of seed coats (Golz et al, 2018;Sechet et al, 2018) and the rhizosheath (Sasse et al, 2018) underpins the potential of this field. With this review we first highlight the wealth of the different sticky mucilage types that are produced by plants.…”

Seed coat mediated resistance against Aspergillus flavus infection in peanut

“…Seed coat cell layers are compressed and desiccated during the seed coat development (Fig. 1), and the dried seed coats are primarily composed of cell wall material (Western et al, 2000;Sechet et al, 2018;Mendu et al, 2011a;Mendu et al, 2011b). Plant cell walls are mainly composed of cellulose, hemicellulose, pectin, lignin, phenolic compound polymers, and structural proteins.…”

Developmental Analysis of Mimulus Seed Transcriptomes Reveals Functional Gene Expression Clusters and Four Imprinted, Endosperm-Expressed Genes

“…Coordinated development between seed tissues is critical to ensuring normal development and plays a major role in determining the size of mature seeds (Garcia et al, 2003;Ingouff et al, 2006;Sechet et al, 2018), and recent improvements in transcriptomics have greatly improved our knowledge of the gene expression dynamics involved (Belmonte et al, 2013). In Arabidopsis, many genes are seed specific, including transcription factors (TFs) that regulate gene networks involved in cell differentiation and nutrient storage (Le et al, 2010;Chen et al, 2014;Yi et al, 2019).…”