Polymorphism and modulation of cell wall esterase enzyme activities in the chicory root during the growing season.
Pectins are major components of the primary plant cell wall. They can be both methylesterified and acetylesterified and de-esterification occurs by specific esterases. Proteins extracted by NaCl treatment from root cell walls of two chicory varieties (Cichorium intybus L. cv. Nausica and Arancha) sampled in an experimental field every 2 weeks between July 2002 and January 2003 were analysed by isoelectrofocalization, semi-denaturing SDS-PAGE, and quantitative assays for their esterase activity. Zymograms showed that chicory root pectin methylesterases belong to a multigene family. The isoelectric points of the pectin methylesterase isoforms ranged from pI 3.8 to pI 9.0. Concerning acetylesterases, only acidic isoforms between pI 4.1 and pI 5.2 were observed, but a large polymorphism of this class of enzymes could be identified in one variety. The results indicate that the root pectin methylesterase activity of the Nausica variety was correlated with ambient temperature, while no significant effect of temperature could be detected on any acetylesterase isoform.
Thonar
Cécile
C
Unité de Recherche en Biologie cellulaire végétale, Facultés Universitaires Notre-Dame de la Paix, Rue de Bruxelles 61, B-5000 Namur, Belgium.
Liners
Françoise
F
Van Cutsem
Pierre
P
D000115:Acetylesterase / Q000378:metabolism*; D002265:Carboxylic Ester Hydrolases / Q000378:metabolism*; D002473:Cell Wall / Q000201:enzymology*; D018651:Cichorium intybus / Q000201:enzymology*; D004591:Electrophoresis, Polyacrylamide Gel; D007525:Isoelectric Focusing; D007527:Isoenzymes / Q000378:metabolism; D018517:Plant Roots / Q000201:enzymology*; D012044:Regression Analysis; D012621:Seasons
D007527:Isoenzymes; D002265:Carboxylic Ester Hydrolases; C022323:pectinesterase; D000115:Acetylesterase