Cell wall mutants

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Biosynthesis of cellulose

Volume 2 - Section II - Chapitre 2.22 Collection: Reference Module in Chemistry, Molecular Sciences and Chemical EngineeringInternational audienc

Probing the mechanical contributions of the pectin matrix: Insights for cell growth

The plant cell wall has a somewhat paradoxical mechanical role in the plant: it must be strong enough to resist the high turgor of the cell contents, but at the right moment it must yield to that pressure to allow cell growth. The control of the cell wall's mechanical properties underlies its ability to regulate growth correctly. Recently, we have reported on changes in cell wall elasticity associated with organ formation at the shoot apical meristem in Arabidopsis thaliana. These changes in cell wall elasticity were strongly correlated with changes in pectin matrix chemistry, and we have previously shown that changes in pectin chemistry can dramatically effect organ formation. These findings point to a important role of the cell wall pectin matrix in cell growth control of higher plants. In this addendum we will discuss the biological significance of these new observations, and will place the scientific advances made possible through Atomic Force Microscopy-based nano-indentations in a relatable context with past experiments on cell wall mechanics

The expression pattern of the tonoplast intrinsic protein gamma-TIP in Arabidopsis thaliana is correlated with cell enlargement

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Les marqueurs AFLP : révélation a l'aide d'un séquenceur automatique et mise au point sur Arabidopsis thaliana et Pisum sativum

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Gibberellin and ethylene control endoreduplication levels in the Arabidopsis thaliana hypocotyl

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Endoreduplication and development: rule without dividing ?

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Classification and identification of arabidopsis cell wall mutants using fourier transfrom infrared (FT-IR) microspectroscopy

We have developed a novel procedure for the rapid classification and identification of Arabidopsis mutants with altered cell wall architecture based on Fourier-Transform infrared (FT-IR) micro-spectroscopy. FT-IR transmission spectra were sampled from native 4 day-old dark-grown hypocotyls of 46 mutants and wild type treated with various drugs. The Mahalanobis distance between mutants, calculated from the spectral information after compression with the Discriminant Variables Selection procedure, was used for a hierarchical cluster analysis. Despite the completely unsupervised nature of the classification procedure we show that all mutants with cellulose defects appeared in the same cluster. In addition, mutant alleles of similar strength for several unrelated loci were also clustered, which demonstrates the sensitivity of the method to detect a wide array of cell wall defects. Comparing the cellulose-deficient cluster with the cluster that contained wild type controls led to the identification of wavenumbers that were diagnostic for altered cellulose content in the context of an intact cell wall. The results show that FT-IR spectra can be used to identify different classes of mutants and to characterize cell wall changes at a microscopic level in unknown mutants. This procedure significantly accelerates the identification and classification of cell wall mutants, which makes cell wall polysaccharides more accessible to functional genomics approaches

Phytochrome controls the number of endoreduplication cycles in the Arabidopsis thaliana hypocotyl

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Regulated trafficking of cellulose synthases

New findings reveal that proteins involved in cellulose biosynthesis undergo regulated trafficking between intracellular compartments and the plasma membrane. The coordinated secretion and internalization of these proteins involve both the actin and cortical microtubule cytoskeletons. This regulated trafficking allows the dynamic remodeling of cellulose synthase complex (CSC) secretion during cell expansion and differentiation. Several new actors of the cellulose synthesis machinery have been recently identified