title: Manipulation of starch granule size distribution in potato tubers by modulation of plastid division.
abstract: Starch granule size is an important parameter for starch applications in industry. Starch granules are formed in amyloplasts, which are, like chloroplasts, derived from proplastids. Division processes and associated machinery are likely to be similar for all plastids. Essential roles for FtsZ proteins in plastid division in land plants have been revealed. FtsZ forms the so-called Z ring which, together with inner and outer plastid division rings, brings about constriction of the plastid. It has been shown that modulation of the expression level of FtsZ may result in altered chloroplast size and number. To test whether FtsZ is also involved in amyloplast division and whether this, in turn, may affect the starch granule size in crop plants, FtsZ protein levels were either reduced or increased in potato. As shown previously in other plant species, decreased StFtsZ1 protein levels in leaves resulted in a decrease in the number of chloroplasts in guard cells. More interestingly, plants with increased StFtsZ1 protein levels in tubers resulted in less, but larger, starch granules. This suggests that the stoichiometry between StFtsZ1 and other components of the plastid division machinery is important for its function. Starch from these tubers also had altered pasting properties and phosphate content. The importance of our results for the starch industry is discussed.
authors.affiliation: TNO Nutrition and Food Research, Department of Applied Plant Sciences, Zernikedreef 9, 2333 CK Leiden, the Netherlands. pater@rulbim.leidenuniv.nl
authors.forename: Sylvia
authors.initials: S
authors.lastname: de Pater
authors.forename: Martien
authors.initials: M
authors.lastname: Caspers
authors.forename: Marijke
authors.initials: M
authors.lastname: Kottenhagen
authors.forename: Henk
authors.initials: H
authors.lastname: Meima
authors.forename: Renaldo
authors.initials: R
authors.lastname: ter Stege
authors.forename: Nick
authors.initials: N
authors.lastname: de Vetten
mesh_terms: D000595:Amino Acid Sequence; D029681:Arabidopsis Proteins; D002736:Chloroplasts / Q000378:metabolism / Q000648:ultrastructure; D003001:Cloning, Molecular; D017343:Genes, Plant; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics*; D035281:Plant Tubers / Q000737:chemistry / Q000235:genetics / Q000648:ultrastructure; D030821:Plants, Genetically Modified / Q000737:chemistry / Q000235:genetics / Q000648:ultrastructure; D018087:Plastids / Q000737:chemistry / Q000378:metabolism / Q000648:ultrastructure*; D011401:Promoter Regions, Genetic; D011198:Solanum tuberosum / Q000737:chemistry* / Q000235:genetics* / Q000648:ultrastructure; D013213:Starch / Q000737:chemistry*; D014170:Transformation, Genetic
chemical_list: D029681:Arabidopsis Proteins; C095113:FTSZ protein, Arabidopsis; D010940:Plant Proteins; D013213:Starch