title: The Arabidopsis plastidic glucose 6-phosphate/phosphate translocator GPT1 is essential for pollen maturation and embryo sac development.
abstract: Plastids of nongreen tissues can import carbon in the form of glucose 6-phosphate via the glucose 6-phosphate/phosphate translocator (GPT). The Arabidopsis thaliana genome contains two homologous GPT genes, AtGPT1 and AtGPT2. Both proteins show glucose 6-phosphate translocator activity after reconstitution in liposomes, and each of them can rescue the low-starch leaf phenotype of the pgi1 mutant (which lacks plastid phosphoglucoisomerase), indicating that the two proteins are also functional in planta. AtGPT1 transcripts are ubiquitously expressed during plant development, with highest expression in stamens, whereas AtGPT2 expression is restricted to a few tissues, including senescing leaves. Disruption of GPT2 has no obvious effect on growth and development under greenhouse conditions, whereas the mutations gpt1-1 and gpt1-2 are lethal. In both gpt1 lines, distorted segregation ratios, reduced efficiency of transmission in males and females, and inability to complete pollen and ovule development were observed, indicating profound defects in gametogenesis. Embryo sac development is arrested in the gpt1 mutants at a stage before the fusion of the polar nuclei. Mutant pollen development is associated with reduced formation of lipid bodies and small vesicles and the disappearance of dispersed vacuoles, which results in disintegration of the pollen structure. Taken together, our results indicate that GPT1-mediated import of glucose 6-phosphate into nongreen plastids is crucial for gametophyte development. We suggest that loss of GPT1 function results in disruption of the oxidative pentose phosphate cycle, which in turn affects fatty acid biosynthesis.
authors.affiliation: Botanisches Institut der Universität zu Köln, D-50931 Köln, Germany.
authors.forename: Patrycja
authors.initials: P
authors.lastname: Niewiadomski
authors.forename: Silke
authors.initials: S
authors.lastname: Knappe
authors.forename: Stefan
authors.initials: S
authors.lastname: Geimer
authors.forename: Karsten
authors.initials: K
authors.lastname: Fischer
authors.forename: Burkhard
authors.initials: B
authors.lastname: Schulz
authors.forename: Ulrike S
authors.initials: US
authors.lastname: Unte
authors.forename: Mario G
authors.initials: MG
authors.lastname: Rosso
authors.forename: Peter
authors.initials: P
authors.lastname: Ache
authors.forename: Ulf-Ingo
authors.initials: UI
authors.lastname: Flügge
authors.forename: Anja
authors.initials: A
authors.lastname: Schneider
mesh_terms: D000483:Alleles; D017920:Antiporters / Q000235:genetics / Q000378:metabolism*; D017360:Arabidopsis / Q000196:embryology / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D018744:DNA, Plant / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D005816:Genetic Complementation Test; D008854:Microscopy, Electron; D009004:Monosaccharide Transport Proteins / Q000235:genetics / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified; D018087:Plastids / Q000378:metabolism; D011058:Pollen / Q000254:growth & development / Q000648:ultrastructure
chemical_list: D017920:Antiporters; D029681:Arabidopsis Proteins; D018744:DNA, Plant; C000592795:GPT2 protein, Arabidopsis; D009004:Monosaccharide Transport Proteins; D010940:Plant Proteins; C111261:glucose 6-phosphate(transporter)
references.citation: Plant Cell. 1992 Aug;4(8):889-99
references.pmid: 1356535
references.citation: Plant Cell. 2003 Aug;15(8):1872-87
references.pmid: 12897259
references.citation: Planta. 1999 Jul;209(1):53-65
references.pmid: 10467031
references.citation: Plant Physiol. 2002 Feb;128(2):512-22
references.pmid: 11842155
references.citation: Plant Cell. 2002 Jun;14(6):1191-206
references.pmid: 12084821
references.citation: Plant Mol Biol. 2000 Apr;42(6):819-32
references.pmid: 10890530
references.citation: Plant Physiol. 2004 Sep;136(1):2621-32
references.pmid: 15375207
references.citation: Stain Technol. 1969 May;44(3):117-22
references.pmid: 4181665
references.citation: Plant Physiol. 1995 Sep;109(1):113-121
references.pmid: 12228584
references.citation: Plant J. 2002 Dec;32(5):685-99
references.pmid: 12472685
references.citation: Plant J. 2003 Dec;36(6):931-45
references.pmid: 14675456
references.citation: Biochem J. 1988 Oct 15;255(2):391-6
references.pmid: 2849412
references.citation: Plant Cell. 1997 Mar;9(3):453-62
references.pmid: 9090886
references.citation: Plant J. 2003 Jan;33(1):75-86
references.pmid: 12943542
references.citation: Plant Cell. 2004;16 Suppl:S142-53
references.pmid: 15037731
references.citation: Plant Physiol. 2000 May;123(1):319-26
references.pmid: 10806248
references.citation: Development. 1998 Oct;125(19):3789-99
references.pmid: 9729487
references.citation: Plant Physiol. 1993 Apr;101(4):1201-1207
references.pmid: 12231774
references.citation: Plant Cell Physiol. 2003 Nov;44(11):1192-201
references.pmid: 14634156
references.citation: Plant Physiol. 2003 Mar;131(3):1178-90
references.pmid: 12644669
references.citation: Plant Physiol. 1993 Jan;101(1):303-312
references.pmid: 12231686
references.citation: Plant Mol Biol. 1992 Dec;20(6):1195-7
references.pmid: 1463855
references.citation: Annu Rev Plant Physiol Plant Mol Biol. 1999 Jun;50:27-45
references.pmid: 15012202
references.citation: Plant Cell. 1993 Oct;5(10):1291-1301
references.pmid: 12271029
references.citation: Plant Physiol. 1985 Sep;79(1):11-7
references.pmid: 16664354
references.citation: Methods Mol Biol. 1998;82:259-66
references.pmid: 9664431
references.citation: Plant Cell. 1998 Jan;10(1):105-17
references.pmid: 9477574
references.citation: Bioinformatics. 2003 Jul 22;19(11):1441-2
references.pmid: 12874060
references.citation: Plant Physiol. 1988 Apr;86(4):1131-5
references.pmid: 16666044
references.citation: Science. 2003 Aug 1;301(5633):653-7
references.pmid: 12893945
references.citation: Plant Cell. 2002 Sep;14(9):2215-32
references.pmid: 12215516
references.citation: Plant J. 1997 Mar;11(3):549-62
references.pmid: 9107041
references.citation: Plant Cell. 1995 Jul;7(7):957-70
references.pmid: 7640528
references.citation: Plant Cell. 2000 Mar;12(3):405-18
references.pmid: 10715326
references.citation: Plant Physiol. 2004 Mar;134(3):1227-39
references.pmid: 14988481
references.citation: Plant Cell. 1998 Jan;10(1):5-17
references.pmid: 9477569
references.citation: Genetics. 1998 Jun;149(2):621-31
references.pmid: 9611178
references.citation: Proc Natl Acad Sci U S A. 1993 Mar 15;90(6):2155-9
references.pmid: 11607374
references.citation: Plant Physiol. 1985 Dec;79(4):977-82
references.pmid: 16664556
references.citation: Mol Gen Genet. 2000 Jul;263(6):978-86
references.pmid: 10954083
references.citation: Plant Cell. 1989 Jul;1(7):657-664
references.pmid: 12359904
references.citation: Plant J. 2003 Nov;36(3):411-20
references.pmid: 14617097
references.citation: Plant Physiol. 2000 Dec;124(4):1465-7
references.pmid: 11115860
references.citation: Curr Opin Plant Biol. 2003 Jun;6(3):236-46
references.pmid: 12753973
references.citation: Trends Plant Sci. 2002 Aug;7(8):345-51
references.pmid: 12167329
references.citation: Plant Physiol. 2001 Feb;125(2):818-27
references.pmid: 11161039
references.citation: Plant J. 1995 Sep;8(3):457-63
references.pmid: 7550382
references.citation: J Cell Biol. 1963 Apr;17:208-12
references.pmid: 13986422
references.citation: Plant J. 2002 Mar;29(6):761-70
references.pmid: 12148534
references.citation: Plant Cell. 2004;16 Suppl:S133-41
references.pmid: 15075395
references.citation: Cell. 1999 Jan 22;96(2):245-54
references.pmid: 9988219
references.citation: Plant J. 1993 Aug;4(2):403-10
references.pmid: 8106085