Metabolism of hemicelluloses by root-associated Bacteroidota species.

Bacteroidota species are enriched in the plant microbiome and provide several beneficial functions for their host, including disease suppression. Determining the mechanisms that enable bacteroidota to colonise plant roots may therefore provide opportunities for enhancing crop production through microbiome engineering. By focusing on nutrient acquisition mechanisms, we discovered Bacteroidota species lack high affinity ATP-binding cassette transporters common in other plant-associated bacteria for capturing simple carbon exudates.

Ectopic callose deposition into woody biomass modulates the nano-architecture of macrofibrils.

Plant biomass plays an increasingly important role in the circular bioeconomy, replacing non-renewable fossil resources. Genetic engineering of this lignocellulosic biomass could benefit biorefinery transformation chains by lowering economic and technological barriers to industrial processing. However, previous efforts have mostly targeted the major constituents of woody biomass: cellulose, hemicellulose and lignin.

Altering arabinans increases Arabidopsis guard cell flexibility and stomatal opening.

Stomata regulate plant water use and photosynthesis by controlling leaf gas exchange. They do this by reversibly opening the pore formed by two adjacent guard cells, with the limits of this movement ultimately set by the mechanical properties of the guard cell walls and surrounding epidermis. A body of evidence demonstrates that the methylation status and cellular patterning of pectin wall polymers play a core role in setting the guard cell mechanical properties, with disruption of the system leading to poorer stomatal performance.

A comparative meta-proteomic pipeline for the identification of plasmodesmata proteins and regulatory conditions in diverse plant species.

Background: A major route for cell-to-cell signalling in plants is mediated by cell wall-embedded pores termed plasmodesmata forming the symplasm. Plasmodesmata regulate the plant development and responses to the environment; however, our understanding of what factors or regulatory cues affect their structure and permeability is still limited. In this paper, a meta-analysis was carried out for the identification of conditions affecting plasmodesmata transport and for the in silico prediction of plasmodesmata proteins in species for which the plasmodesmata proteome has not been experimentally determined.

Immunofluorescence Detection of Callose in Plant Tissue Sections.

The accumulation of the cell wall component callose at plasmodesmata (PD) is crucial for the regulation of symplastic intercellular transport in plants. Here we describe protocols to fluorescently image callose in sectioned plant tissue using monoclonal antibodies. This protocol achieves high-resolution images by the fixation, embedding, and sectioning of plant material to expose internal cell walls.

Cell Wall Polymer Composition and Spatial Distribution in Ripe Banana and Mango Fruit: Implications for Cell Adhesion and Texture Perception.

Banana () and mango () are two of the most popular fruits eaten worldwide. They both soften during ripening but their textural attributes are markedly different. This study aimed to elucidate the molecular mechanism underpinning textural differences between banana and mango.

Interactions between callose and cellulose revealed through the analysis of biopolymer mixtures.

The properties of (1,3)-β-glucans (i.e., callose) remain largely unknown despite their importance in plant development and defence.

Emerging models on the regulation of intercellular transport by plasmodesmata-associated callose.

The intercellular transport of molecules through membranous channels that traverse the cell walls-so-called plasmodesmata-is of fundamental importance for plant development. Regulation of plasmodesmata aperture (and transport capacity) is mediated by changes in the flanking cell walls, mainly via the synthesis/degradation (turnover) of the (1,3)-β-glucan polymer callose. The role of callose in organ development and in plant environmental responses is well recognized, but detailed understanding of the mechanisms regulating its accumulation and its effects on the structure and permeability of the channels is still missing.

Stomatal Opening Involves Polar, Not Radial, Stiffening Of Guard Cells.

It has long been accepted that differential radial thickening of guard cells plays an important role in the turgor-driven shape changes required for stomatal pore opening to occur [1-4]. This textbook description derives from an original interpretation of structure rather than measurement of mechanical properties. Here we show, using atomic force microscopy, that although mature guard cells display a radial gradient of stiffness, this is not present in immature guard cells, yet young stomata show a normal opening response.

Stomatal Function Requires Pectin De-methyl-esterification of the Guard Cell Wall.

Stomatal opening and closure depends on changes in turgor pressure acting within guard cells to alter cell shape [1]. The extent of these shape changes is limited by the mechanical properties of the cells, which will be largely dependent on the structure of the cell walls. Although it has long been observed that guard cells are anisotropic due to differential thickening and the orientation of cellulose microfibrils [2], our understanding of the composition of the cell wall that allows them to undergo repeated swelling and deflation remains surprisingly poor.