Deficiency of adenosine kinase activity affects the degree of pectin methyl-esterification in cell walls of Arabidopsis thaliana

• Published in: Planta Vol. 224; no. 6; pp. 1401 - 1414
• Main Authors: Pereira, L. A. R., Schoor, S., Goubet, F., Dupree, P., Moffatt, B. A.
• Format: Journal Article
• Language: English
• Published: Berlin Springer-Verlag 01-11-2006; Springer; Springer Nature B.V
• Subjects: Adenosine Kinase - metabolism; Antibodies; Arabidopsis - enzymology; Bacteria; Biological and medical sciences; Carboxylic Ester Hydrolases - metabolism; Cell adhesion; Cell biochemistry; Cell physiology; Cell Wall - enzymology; Cell walls; Epitopes; Esterification; Flowers & plants; Fluorescent Antibody Technique; Fundamental and applied biological sciences. Psychology; Hypocotyls; Intercellular junctions; Leaves; Mesophyll cells; Plant cells; Plant physiology and development; Plants; Arabidopsis thaliana; Cell walls Monoclonal antibodies (JIM5, JIM7, LM7); Cruciferae; Enzyme; Adenosine kinase; Arabidopsis; Dicotyledones; Transferases; Angiospermae; Spermatophyta; Methyl-esterification, Pectin; Cell wall
• ISSN: 0032-0935; 1432-2048
• DOI: 10.1007/s00425-006-0323-z

Pectin methyl-esterification is catalysed by S-adenosyl-L-methionine (SAM)-dependent methyltransferases. As deficiency in adenosine kinase (ADK; EC 2.7.1.20) activity impairs SAM recycling and utilization, we investigated the relationship between ADK-deficiency and the degree of pectin methyl-esterification in cell walls of Arabidopsis thaliana. The distribution patterns of epitopes associated with methyl-esterified homogalacturonan in leaves and hypocotyls of wild-type (WT) and ADK-deficient plants were examined using immunolocalization and biochemical techniques. JIM5 and LM7 epitopes, characteristic of low esterified pectins, were more irregularly distributed along the cell wall in ADK-deficient plants than in WT cell walls. In addition, epitopes recognized by JIM7, characteristic of pectins with a higher degree of methyl-esterification, were less abundant in ADK-deficient leaves and hypocotyls. Since de-esterified pectins have enhanced adhesion properties, we propose that the higher abundance and the altered distribution of low methyl-esterified pectin in ADK-deficient cell walls lead to the leaf shape abnormalities observed in these plants.