Defoliation induces fructan 1-exohydrolase II in Witloof chicory roots. Cloning and purification of two isoforms, fructan 1-exohydrolase IIa and fructan 1-exohydrolase IIb. Mass fingerprint of the fructan 1-exohydrolase II enzymes.
The cloning of two highly homologous chicory (Cichorium intybus var. foliosum cv Flash) fructan 1-exohydrolase cDNAs (1-FEH IIa and 1-FEH IIb) is described. Both isoenzymes could be purified from forced chicory roots as well as from the etiolated "Belgian endive" leaves where the 1-FEH IIa isoform is present in higher concentrations. Full-length cDNAs were obtained by a combination of reverse transcriptase-polymerase chain reaction (PCR), PCR and 5'- and 3'-rapid amplification of cDNA ends using primers based on N-terminal and conserved amino acid sequences. 1-FEH IIa and 1-FEH IIb cDNA-derived amino acid sequences are most homologous to a new group of plant glycosyl hydrolases harboring cell wall-type enzymes with acid isoelectric points. Unlike the observed expression profiles of chicory 1-FEH I, northern analysis revealed that 1-FEH II is expressed when young chicory plants are defoliated, suggesting that this enzyme can be induced at any developmental stage when large energy supplies are necessary (regrowth after defoliation).
Van den Ende
W
W
Department of Biology, Laboratory for Developmental Biology, Botany Institute, K.U. Leuven, Kasteelpark Arenberg 31, B-3001 Leuven, Belgium. wim.vandenende@bio.kuleuven.ac.be
Michiels
A
A
Van Wonterghem
D
D
Clerens
S P
SP
De Roover
J
J
Van Laere
A J
AJ
D000595:Amino Acid Sequence; D018651:Cichorium intybus / Q000201:enzymology* / Q000235:genetics; D003001:Cloning, Molecular; D005091:Exons; D006026:Glycoside Hydrolases / Q000235:genetics* / Q000302:isolation & purification; D007527:Isoenzymes / Q000235:genetics* / Q000302:isolation & purification; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000378:metabolism; D018515:Plant Leaves / Q000502:physiology*; D018517:Plant Roots / Q000201:enzymology*; D017386:Sequence Homology, Amino Acid; D043324:beta-Fructofuranosidase
D007527:Isoenzymes; D010446:Peptide Fragments; D006026:Glycoside Hydrolases; D043324:beta-Fructofuranosidase; C044118:fructan beta-fructosidase