TBL38 atypical homogalacturonan-acetylesterase activity and cell wall microdomain localization in Arabidopsis seed mucilage secretory cells.

Plant cell walls constitute complex polysaccharidic/proteinaceous networks whose biosynthesis and dynamics implicate several cell compartments. The synthesis and remodeling of homogalacturonan pectins involve Golgi-localized methylation/acetylation and subsequent cell wall-localized demethylation/deacetylation. So far, TRICHOME BIREFRINGENCE-LIKE (TBL) family members have been described as Golgi-localized acetyltransferases targeting diverse hemicelluloses or pectins.

Genome wide association study of Arabidopsis seed mucilage layers at a regional scale.

The myxospermous species Arabidopsis thaliana extrudes a polysaccharidic mucilage from the seed coat epidermis during imbibition. The whole seed mucilage can be divided into a seed-adherent layer and a fully soluble layer, both layers presenting natural genetic variations. The adherent mucilage is variable in size and composition, while the soluble mucilage is variable in composition and physical properties.

Medicinal plants enter the single-cell multi-omics era.

Elucidating biosynthetic pathways of plant specialized metabolites is a tricky but essential task for the biotechnological production of plant drugs. In a new report, Li et al. used a single-cell multi-omics approach to provide an integrative view of the architecture and regulation of anticancer alkaloid routes in Madagascar periwinkle.

Immunochemical Identification of the Main Cell Wall Polysaccharides of the Early Land Plant .

Plant primary cell walls are composite structures surrounding the protoplast and containing pectins, hemicelluloses, and cellulose polysaccharides, as well as proteins. Their composition changed during the evolution of the green lineage from algae to terrestrial plants, i.e.

CBMs as Probes to Explore Plant Cell Wall Heterogeneity Using Immunocytochemistry.

Immunocytochemistry is a widely used technique to localize antigen within intact tissues. Plant cell walls are complex matrixes of highly decorated polysaccharides and the large number of CBM families displaying specific substrate recognition reflects this complexity. The accessibility of large proteins, such as antibodies, to their cell wall epitopes may be sometimes difficult due to steric hindrance problems.

RNA In Situ Hybridization of Paraffin Sections to Characterize the Multicellular Compartmentation of Plant Secondary Metabolisms.

As a mean to cope with their potential cytotoxicity for the host plant, secondary metabolisms are often sequestered within specific cell types. This spatial organization may reach complex sequential multicellular compartmentation. The most complex example so far characterized is the sequential multicellular biosynthesis of the anticancer monoterpene indole alkaloids in Catharanthus roseus.

Cell-wall microdomain remodeling controls crucial developmental processes.

Plant cell walls display cellular and subcellular specificities. At the subcellular level, wall regional territories with specific compositions are necessary for macroscopic developmental processes. These regional specificities were named differently throughout the years, and are unified here under the term 'cell-wall microdomains' that define the local composition and organization of wall polymers underlying territories of wall loosening and/or softening or stiffening.

Interaction of two MADS-box genes leads to growth phenotype divergence of all-flesh type of tomatoes.

All-flesh tomato cultivars are devoid of locular gel and exhibit enhanced firmness and improved postharvest storage. Here, we show that SlMBP3 is a master regulator of locular tissue in tomato fruit and that a deletion at the gene locus underpins the All-flesh trait. Intriguingly, All-flesh varieties lack the deleterious phenotypes reported previously for SlMBP3 under-expressing lines and which preclude any potential commercial use.

Myxospermy Evolution in Brassicaceae: A Highly Complex and Diverse Trait with as an Uncommon Model.

The ability to extrude mucilage upon seed imbibition (myxospermy) occurs in several Angiosperm taxonomic groups, but its ancestral nature or evolutionary convergence origin remains misunderstood. We investigated seed mucilage evolution in the Brassicaceae family with comparison to the knowledge accumulated in . The myxospermy occurrence was evaluated in 27 Brassicaceae species.

The Jo-In protein welding system is a relevant tool to create CBM-containing plant cell wall degrading enzymes.

Irrespective of their biological origin, most proteins are composed of several elementary domains connected by linkers. These domains are either functionally independent units, or part of larger multidomain structures whose functions are defined by their spatial proximity. Carbohydrate-degrading enzymes provide examples of a range of multidomain structures, in which catalytic protein domains are frequently appended to one or more non-catalytic carbohydrate-binding modules which specifically bind to carbohydrate motifs.

An integrative Study Showing the Adaptation to Sub-Optimal Growth Conditions of Natural Populations of : A Focus on Cell Wall Changes.

In the global warming context, plant adaptation occurs, but the underlying molecular mechanisms are poorly described. Studying natural variation of the model plant adapted to various environments along an altitudinal gradient should contribute to the identification of new traits related to adaptation to contrasted growth conditions. The study was focused on the cell wall (CW) which plays major roles in the response to environmental changes.

The Class III Peroxidase Encoding Gene Positively and Spatiotemporally Regulates the Low pH-Induced Cell Death in Roots.

Exogenous low pH stress causes cell death in root cells, limiting root development, and agricultural production. Different lines of evidence suggested a relationship with cell wall (CW) remodeling players. We investigated whether class III peroxidase (CIII Prx) total activity, CIII Prx candidate gene expression, and reactive oxygen species (ROS) could modify CW structure during low pH-induced cell death in roots.

Coordination of five class III peroxidase-encoding genes for early germination events of Arabidopsis thaliana.

The Class III peroxidases (CIII Prxs) belong to a plant-specific multigene family. Thanks to their double catalytic cycle they can oxidize compounds or release reactive oxygen species (ROS). They are either involved in different cell wall stiffening processes such as lignification and suberization, in cell wall loosening or defense mechanisms.

Plant Cell Wall Proteomes: Bioinformatics and Cell Biology Tools to Assess the Bona Fide Cell Wall Localization of Proteins.

The purification of plant cell walls is challenging because they constitute an open compartment which is not limited by a membrane like the cell organelles. Different strategies have been established to limit the contamination by proteins of other compartments in cell wall proteomics studies. Non-destructive methods rely on washing intact cells with various types of solutions without disrupting the plasma membrane in order to elute cell wall proteins.

Seed mucilage evolution: Diverse molecular mechanisms generate versatile ecological functions for particular environments.

Plant myxodiasporous species have the ability to release a polysaccharidic mucilage upon imbibition of the seed (myxospermy) or the fruit (myxocarpy). This is a widespread capacity in angiosperms providing multiple ecological functions including higher germination efficiency under environmental stresses. It is unclear whether myxodiaspory has one or multiple evolutionary origins and why it was supposedly lost in several species.

Cellular and Subcellular Compartmentation of the 2-Methyl-D-Erythritol 4-Phosphate Pathway in the Madagascar Periwinkle.

The Madagascar periwinkle () synthesizes the highly valuable monoterpene indole alkaloids (MIAs) through a long metabolic route initiated by the 2-methyl-D-erythritol 4-phosphate (MEP) pathway. In leaves, a complex compartmentation of the MIA biosynthetic pathway occurs at both the cellular and subcellular levels, notably for some gene products of the MEP pathway. To get a complete overview of the pathway organization, we cloned four genes encoding missing enzymes involved in the MEP pathway before conducting a systematic analysis of transcript distribution and protein subcellular localization.

Medium-Throughput RNA In Situ Hybridization of Serial Sections from Paraffin-Embedded Tissue Microarrays.

(m)RNA spatiotemporal pattern of distribution is of key importance to decipher gene function. In this post-genomic era, numerous transcriptomic studies are made publicly available, sometimes reaching a tissular resolution and even more rarely the cellular level. This "one tissue-numerous genes" information can be completed by the reverse "one gene-numerous tissues" picture through traditional RNA in situ hybridization (ISH).

Pectin Demethylesterification Generates Platforms that Anchor Peroxidases to Remodel Plant Cell Wall Domains.

Plant cell walls are made of polysaccharidic-proteinaceous complex matrices. Molecular interactions governing their organization remain understudied. We take advantage of the highly dynamic cell walls of Arabidopsis seed mucilage secretory cells to propose a hierarchical multi-molecular interaction model within a cell wall domain.

Plant Cell Wall Proteomics as a Strategy to Reveal Candidate Proteins Involved in Extracellular Lipid Metabolism.

Plant cell walls are composite structures surrounding cells and involved in both mechanical support and perception of their environment. They are mainly composed of polysaccharides (90-95% of their mass) and proteins (5-10%). The cell wall proteins (CWPs) contribute to the arrangements and modifications of polymer networks and to cell-to-cell communication.

Cell wall modifications of two Arabidopsis thaliana ecotypes, Col and Sha, in response to sub-optimal growth conditions: An integrative study.

With the global temperature change, plant adaptations are predicted, but little is known about the molecular mechanisms underlying them. Arabidopsis thaliana is a model plant adapted to various environmental conditions, in particular able to develop along an altitudinal gradient. Two ecotypes, Columbia (Col) growing at low altitude, and Shahdara (Sha) growing at 3400m, have been studied at optimal and sub-optimal growth temperature (22°C vs 15°C).

CBMs as Probes to Explore Plant Cell Wall Heterogeneity Using Immunocytochemistry.

Immunocytochemistry is a widely used technique to localize antigen within intact tissues. Plant cell walls are complex matrixes of highly decorated polysaccharides and the large number of CBM families displaying specific substrate recognition reflects this complexity. The accessibility of large proteins, such as antibodies, to their cell wall epitopes may be sometimes difficult due to steric hindrance problems.

The Lipid Transfer Protein 2 (AtLTP2) Is Involved in Cuticle-Cell Wall Interface Integrity and in Etiolated Hypocotyl Permeability.

Plant non-specific lipid transfer proteins (nsLTPs) belong to a complex multigenic family implicated in diverse physiological processes. However, their function and mode of action remain unclear probably because of functional redundancy. Among the different roles proposed for nsLTPs, it has long been suggested that they could transport cuticular precursor across the cell wall during the formation of the cuticle, which constitutes the first physical barrier for plant interactions with their aerial environment.

Class II Cytochrome P450 Reductase Governs the Biosynthesis of Alkaloids.

Expansion of the biosynthesis of plant specialized metabolites notably results from the massive recruitment of cytochrome P450s that catalyze multiple types of conversion of biosynthetic intermediates. For catalysis, P450s require a two-electron transfer catalyzed by shared cytochrome P450 oxidoreductases (CPRs), making these auxiliary proteins an essential component of specialized metabolism. CPR isoforms usually group into two distinct classes with different proposed roles, namely involvement in primary and basal specialized metabolisms for class I and inducible specialized metabolism for class II.