title: Modification of potato cell wall pectin by the introduction of rhamnogalacturonan lyase and β-galactosidase transgenes and their side effects.
abstract: Genes encoding pectic enzymes were introduced to wild-type potato Karnico. Cell wall materials were extracted from Karnico and transgenic lines expressing β-galactosidase (β-Gal-14 mutant) or rhamnogalacturonan lyase (RGL-18 mutant). After sequential extraction, β-Gal-14 hot buffer-soluble solids (HBSS) of pectin contained 54% less galactose than Karnico HBSS, representing shorter galactan side chains. The individual pectin populations of β-Gal-14 HBSS showed different modifications extended to the two sub-populations as obtained by ion-exchange chromatography. Compared to wild-type, RGL-18 HBSS contained 27% more galacturonic acid and 55% less Gal on fresh potato weight basis, which was due to the removal of galactan-rich rhamnogalacturonan I (RG-I) segments. All pectin populations of RGL-18 showed consistently low levels of RG-I segments. Transgenic modification showed side effects on the methyl-esterification and acetyl substitution of RGL-18 HBSS (DM=53, DA=21), but not of the β-Gal-14 HBSS in comparison to wild-type (DM=29, DA=54).
authors.affiliation: Laboratory of Food Chemistry, Wageningen University, P.O. Box 17, 6700 AA Wageningen, The Netherlands. Electronic address: jie-hong.huang@wur.nl.
authors.forename: Jie-Hong
authors.initials: JH
authors.lastname: Huang
authors.affiliation: Wageningen UR Plant Breeding, Wageningen University and Research Centre, Wageningen, The Netherlands. Electronic address: anne.kortstee@outlook.com.
authors.forename: Anne
authors.initials: A
authors.lastname: Kortstee
authors.affiliation: Wageningen UR Plant Breeding, Wageningen University and Research Centre, Wageningen, The Netherlands. Electronic address: dianka.dees@wur.nl.
authors.forename: Dianka C T
authors.initials: DC
authors.lastname: Dees
authors.affiliation: Wageningen UR Plant Breeding, Wageningen University and Research Centre, Wageningen, The Netherlands. Electronic address: luisa.trindade@wur.nl.
authors.forename: Luisa M
authors.initials: LM
authors.lastname: Trindade
authors.affiliation: Laboratory of Food Chemistry, Wageningen University, P.O. Box 17, 6700 AA Wageningen, The Netherlands. Electronic address: henk.schols@wur.nl.
authors.forename: Henk A
authors.initials: HA
authors.lastname: Schols
authors.affiliation: Laboratory of Food Chemistry, Wageningen University, P.O. Box 17, 6700 AA Wageningen, The Netherlands. Electronic address: Harry.Gruppen@wur.nl.
authors.forename: Harry
authors.initials: H
authors.lastname: Gruppen
mesh_terms: D000085:Acetates / Q000032:analysis; D002473:Cell Wall / Q000201:enzymology; D005690:Galactose / Q000737:chemistry; D010368:Pectins / Q000378:metabolism*; D030821:Plants, Genetically Modified; D011133:Polysaccharide-Lyases / Q000235:genetics* / Q000378:metabolism; D011198:Solanum tuberosum / Q000235:genetics*; D019076:Transgenes; D001616:beta-Galactosidase / Q000235:genetics* / Q000378:metabolism
chemical_list: D000085:Acetates; D010368:Pectins; D001616:beta-Galactosidase; D011133:Polysaccharide-Lyases; D005690:Galactose
keywords: Galactan side chains; Plant cell wall polysaccharides; Potato mutant; Potato pectin; Solanum tuberosum; Starch removal