Antisense expression of the fasciclin-like arabinogalactan protein FLA6 gene in Populus inhibits expression of its homologous genes and alters stem biomechanics and cell wall composition in transgenic trees

How does the deposition of cell wall components structure cell shape and function during leaf ontogenesis? Although this issue has been the subject of several studies, a wide variety of standards have been reported and many knowledge gaps remain. In this study we evaluated cell wall composition in leaf tissues of Lavoisiera mucorifera Mart. & Schrank ex DC. (Melastomataceae) regarding cellulose, pectin (homogalacturonans (HGs) and rhamnogalacturonans I (RGI)) and arabinogalactan protein (AGP) distribution during ontogenesis. Leaf primordium, as well as young and mature leaves, were submitted to histochemical analysis using calcofluor white and ruthenium red, and immunocytochemical analysis using primary monoclonal antibodies (JIM5, JIM7, LM2, LM5 and LM6). Results showed that the distribution of cell wall components depends on tissue and leaf developmental stage. At the beginning of cell differentiation in the leaf primordium, two main patterns of cellulose microfibril orientation occur: perpendicular and random. This initial microfibril arrangement determines final cell shape and leaf tissue functionality in mature leaves. During leaf development, especially in epidermal and collenchyma cells, the association of HGs with low methyl-esterified groups and cellulose guarantees mechanical support. As a result, cell wall properties, such as rigidity and porosity, may also be acquired by changes in cell wall composition and are associated with morphogenetic patterns in L. mucorifera.

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Cell Wall Composition and Ultrastructural Immunolocalization of Pectin and Arabinogalactan Protein during Olea europaea L. Fruit Abscission

Plant and Cell Physiology ◽

10.1093/pcp/pcaa009 ◽

2020 ◽

Vol 61 (4) ◽

pp. 814-825 ◽

Cited By ~ 1

Author(s):

Ruben Parra ◽

Miguel A Paredes ◽

Juana Labrador ◽

Cláudia Nunes ◽

Manuel A Coimbra ◽

...

Keyword(s):

Cell Wall ◽

Cell Separation ◽

Cell Walls ◽

Cell Wall Composition ◽

Arabinogalactan Protein ◽

Cell Wall Polysaccharide ◽

Ripe Fruit ◽

Olive Fruit ◽

Fruit Abscission ◽

Polysaccharide Composition

Abstract Cell wall modification is integral to many plant developmental processes where cells need to separate, such as abscission. However, changes in cell wall composition during natural fruit abscission are poorly understood. In olive (Olea europaea L.), some cultivars such as ‘Picual’ undergo massive natural fruit abscission after fruit ripening. This study investigates the differences in cell wall polysaccharide composition and the localization of pectins and arabinogalactan protein (AGP) in the abscission zone (AZ) during cell separation to understand fruit abscission control in ‘Picual’ olive. To this end, immunogold labeling employing a suite of monoclonal antibodies to cell wall components (JIM13, LM5, LM6, LM19 and LM20) was investigated in olive fruit AZ. Cell wall polysaccharide extraction revealed that the AZ cell separation is related to the de-esterification and degradation of pectic polysaccharides. Moreover, ultrastructural localization showed that both esterified and unesterified homogalacturonans (HGs) localize mainly in the AZ cell walls, including the middle lamella and tricellular junction zones. Our results indicate that unesterified HGs are likely to contribute to cell separation in the olive fruit AZ. Similarly, immunogold labeling demonstrated a decrease in both galactose-rich and arabinose-rich pectins in AZ cell walls during ripe fruit abscission. In addition, AGPs were localized in the cell wall, plasma membrane and cytoplasm of AZ cells with lower levels of AGPs during ripe fruit abscission. This detailed temporal profile of the cell wall polysaccharide composition, and the pectins and AGP immunolocalization in the olive fruit AZ, offers new insights into cell wall remodeling during ripe fruit abscission.

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Gold Nanoparticles-Induced Modifications in Cell Wall Composition in Barley Roots

Cells ◽

10.3390/cells10081965 ◽

2021 ◽

Vol 10 (8) ◽

pp. 1965

Author(s):

Anna Milewska-Hendel ◽

Katarzyna Sala ◽

Weronika Gepfert ◽

Ewa Kurczyńska

Keyword(s):

Gold Nanoparticles ◽

Cell Wall ◽

Cell Walls ◽

Direct Contact ◽

Cell Wall Composition ◽

Arabinogalactan Protein ◽

Chemical Components ◽

Surface Charges ◽

Hordeum Vulgare L ◽

Root Cells

The increased use of nanoparticles (NP) in different industries inevitably results in their release into the environment. In such conditions, plants come into direct contact with NP. Knowledge about the uptake of NP by plants and their effect on different developmental processes is still insufficient. Our studies concerned analyses of the changes in the chemical components of the cell walls of Hordeum vulgare L. roots that were grown in the presence of gold nanoparticles (AuNP). The analyses were performed using the immunohistological method and fluorescence microscopy. The obtained results indicate that AuNP with different surface charges affects the presence and distribution of selected pectic and arabinogalactan protein (AGP) epitopes in the walls of root cells.

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