title: Production of dextran in transgenic potato plants.
abstract: The production of dextran in potato tubers and its effect on starch biosynthesis were investigated. The mature dextransucrase (DsrS) gene from Leuconostoc mesenteroides was fused to the chloroplastic ferredoxin signal peptide (FD) enabling amyloplast entry, which was driven by the highly tuber-expressed patatin promoter. After transformation of two potato genotypes (cv. Kardal and the amylose-free (amf) mutant), dextrans were detected by enzyme-linked immunosorbent assay (ELISA) in tuber juices of Kardal and amf transformants. The dextran concentration appeared two times higher in the Kardal (about 1.7 mg/g FW) than in the amf transformants. No dextran was detected by ELISA inside the starch granule. Interestingly, starch granule morphology was affected, which might be explained by the accumulation of dextran in tuber juices. In spite of that, no significant changes of the physicochemical properties of the starches were detected. Furthermore, we have observed no clear changes in chain length distributions, despite the known high acceptor efficiency of DSRS.
authors.affiliation: Graduate School Experimental Plant Sciences, Laboratory of Plant Breeding, Wageningen University, The Netherlands.
authors.forename: Géraldine A
authors.initials: GA
authors.lastname: Kok-Jacon
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Vincken
authors.forename: Luc C J M
authors.initials: LC
authors.lastname: Suurs
authors.forename: Denong
authors.initials: D
authors.lastname: Wang
authors.forename: Shaoyi
authors.initials: S
authors.lastname: Liu
authors.forename: Richard G F
authors.initials: RG
authors.lastname: Visser
mesh_terms: D002240:Carbohydrate Sequence; D003911:Dextrans / Q000096:biosynthesis* / Q000302:isolation & purification; D004797:Enzyme-Linked Immunosorbent Assay; D015870:Gene Expression; D017343:Genes, Plant; D005964:Glucosyltransferases / Q000235:genetics*; D030821:Plants, Genetically Modified / Q000378:metabolism*; D021382:Protein Sorting Signals / Q000235:genetics; D012313:RNA / Q000302:isolation & purification; D020133:Reverse Transcriptase Polymerase Chain Reaction; D011198:Solanum tuberosum / Q000235:genetics / Q000378:metabolism*; D013213:Starch / Q000096:biosynthesis* / Q000737:chemistry / Q000302:isolation & purification; D013329:Structure-Activity Relationship; D014170:Transformation, Genetic
chemical_list: D003911:Dextrans; D021382:Protein Sorting Signals; D012313:RNA; D013213:Starch; D005964:Glucosyltransferases; C020025:dextransucrase