title: Inhibition of Golgi function causes plastid starch accumulation.
abstract: Little is known about possible interactions between chloroplasts and the Golgi apparatus, although there is increasing evidence for a direct Golgi to chloroplast transport pathway targeting proteins to their destinations within the membranes and stroma of plastids. Here data are presented showing that a blockage of secretion results in a significant increase of starch within plastids. Golgi disassembly promoted either by the secretory inhibitor brefeldin A or through an inducible Sar1-GTP system leads to dramatic starch accumulation in plastids, thus providing evidence for a direct interaction between plastids and Golgi activity. The possibility that starch accumulation is due either to elevated levels of cytosolic sugars because of loss of secretory Golgi activity or even to a blockage of amylase transport from the Golgi to the chloroplast is discussed.
authors.affiliation: School of Life Sciences, Oxford Brookes University, Oxford, UK. eric.hummel@uni-bayreuth.de
authors.forename: Eric
authors.initials: E
authors.lastname: Hummel
authors.forename: Anne
authors.initials: A
authors.lastname: Osterrieder
authors.forename: David G
authors.initials: DG
authors.lastname: Robinson
authors.forename: Chris
authors.initials: C
authors.lastname: Hawes
mesh_terms: D017360:Arabidopsis / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D029681:Arabidopsis Proteins / Q000378:metabolism; D001681:Biological Assay; D020126:Brefeldin A / Q000494:pharmacology; D002696:Chlamydomonas / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D005453:Fluorescence; D005947:Glucose / Q000378:metabolism; D006056:Golgi Apparatus / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D049452:Green Fluorescent Proteins / Q000378:metabolism; D008954:Models, Biological; D018517:Plant Roots / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D018087:Plastids / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D050683:R-SNARE Proteins / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D013194:Staining and Labeling; D013213:Starch / Q000378:metabolism*; D013997:Time Factors; D014026:Nicotiana / Q000166:cytology / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure
chemical_list: D029681:Arabidopsis Proteins; D050683:R-SNARE Proteins; D011993:Recombinant Fusion Proteins; C099591:SAR1 protein, Arabidopsis; D049452:Green Fluorescent Proteins; D020126:Brefeldin A; D013213:Starch; D005947:Glucose