title: Precision breeding for novel starch variants in potato.
abstract: Potato can be used as a source of modified starches for culinary and industrial processes, but its allelic diversity and tetraploid genome make the identification of novel alleles a challenge, and breeding such alleles into elite lines is a slow and difficult process. An efficient and reliable strategy has been developed for the rapid introduction and identification of new alleles in elite potato breeding lines, based on the ethylmethanesulphonate mutagenesis of dihaploid seeds. Using the granule-bound starch synthase I gene (waxy) as a model, a series of point mutations that potentially affect gene expression or enzyme function was identified. The most promising loss-of-function allele (waxy(E1100)) carried a mutation in the 5'-splice donor site of intron 1 that caused mis-splicing and protein truncation. This was used to establish elite breeding lineages lacking granule-bound starch synthase I protein activity and producing high-amylopectin starch. This is the first report of rapid and efficient mutation analysis in potato, a genetically complex and vegetatively propagated crop.
authors.affiliation: Fraunhofer Institute for Molecular Biology and Applied Ecology, Forckenbeckstrasse 6, 52074 Aachen, Germany.
authors.forename: Jost
authors.initials: J
authors.lastname: Muth
authors.forename: Stefanie
authors.initials: S
authors.lastname: Hartje
authors.forename: Richard M
authors.initials: RM
authors.lastname: Twyman
authors.forename: Hans-Reinhard
authors.initials: HR
authors.lastname: Hofferbert
authors.forename: Eckhard
authors.initials: E
authors.lastname: Tacke
authors.forename: Dirk
authors.initials: D
authors.lastname: Prüfer
mesh_terms: D000483:Alleles; D000595:Amino Acid Sequence; D000687:Amylopectin / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D032621:DNA Shuffling / Q000379:methods; D007438:Introns / Q000235:genetics; D008957:Models, Genetic; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism*; D017354:Point Mutation; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D011198:Solanum tuberosum / Q000235:genetics / Q000378:metabolism*; D013213:Starch / Q000096:biosynthesis*; D013214:Starch Synthase / Q000235:genetics / Q000378:metabolism*
chemical_list: D013213:Starch; D000687:Amylopectin; C434607:granule-bound starch synthase I; D013214:Starch Synthase