title: The role of the glyoxylate cycle in the symbiotic fungus Tuber borchii: expression analysis and subcellular localization.
abstract: Expression profiles of isocitrate lyase (TbICL), malate synthase (TbMLS) and fructose-1,6-bisphosphatase (TbFBP) from the mycorrhizal ascomycete Tuber borchii were investigated by real-time RT-PCR in fruiting bodies at different stages of maturation. In addition, a time course experiment was set up to determine how the transcription profile of TbICL, TbMLS and TbFBP in axenic-grown mycelia is affected by different carbon sources. The transcript levels of the three genes in the fruiting bodies were all much higher than those measured in the vegetative stage. The investigation on axenic-grown mycelia revealed that the main positive regulator of TbICL and TbMLS gene expression is the availability of acetate and ethanol, while oleic acid is a too complex substrate for the limited degradative capacities of T. borchii. Immunolabelling on axenic-grown mycelia showed a co-localization of TbICL and the peroxisomal marker protein FOX2. This result demonstrated that in T. borchii ICL is compartmentalized in peroxisomes. The high induction of TbICL, TbMLS and TbFBP transcription and the translocation of lipids in fruiting bodies let us hypothesize that glyoxylate cycle and gluconeogenesis are key metabolic pathways in the recycling of existing cell material and the channelling towards the biosynthesis of new cell components during the maturation of fruiting bodies.
authors: Dipartimento di Biologia Vegetale, Università di Torino and Istituto per la Protezione delle Piante del CNR-Sezione di Torino, Viale Mattioli 25, 10125 Turin, Italy. simona.abba@unito.it
authors: Simona
authors: S
authors: Abba'
authors: Raffaella
authors: R
authors: Balestrini
authors: Alessandra
authors: A
authors: Benedetto
authors: Hanspeter
authors: H
authors: Rottensteiner
authors: José Ramón
authors: JR
authors: De Lucas
authors: Paola
authors: P
authors: Bonfante
mesh_terms: D000085:Acetates / Q000378:metabolism; D001203:Ascomycota / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D000431:Ethanol / Q000378:metabolism; D006597:Fructose-Bisphosphatase / Q000235:genetics / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D015966:Gene Expression Regulation, Fungal; D015723:Gene Library; D005943:Gluconeogenesis; D006038:Glyoxylates / Q000378:metabolism*; D007522:Isocitrate Lyase / Q000235:genetics / Q000378:metabolism*; D008055:Lipids / Q000493:pharmacokinetics; D008292:Malate Synthase / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D019301:Oleic Acid; D020675:Peroxisomes / Q000201:enzymology; D012331:RNA, Fungal / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013347:Subcellular Fractions
chemical_list: D000085:Acetates; D006038:Glyoxylates; D008055:Lipids; D012331:RNA, Fungal; D012333:RNA, Messenger; D019301:Oleic Acid; D000431:Ethanol; D008292:Malate Synthase; D006597:Fructose-Bisphosphatase; D007522:Isocitrate Lyase
references: Plant Physiol. 2001 Nov;127(3):1287-98
references: 11706207
references: Mol Cell Biol. 1995 Apr;15(4):1915-22
references: 7891685
references: Biochem J. 2003 Jul 15;373(Pt 2):357-68
references: 12683951
references: Appl Environ Microbiol. 2006 Sep;72(9):6345-54
references: 16957261
references: Arch Microbiol. 2000 Jul-Aug;174(1-2):59-66
references: 10985743
references: Mol Cell Biochem. 2001 Feb;218(1-2):65-70
references: 11330839
references: Gene. 1997 Oct 1;198(1-2):165-9
references: 9370278
references: Arch Microbiol. 1996 Nov;166(5):336-41
references: 8929280
references: Yeast. 2003 Jul 15;20(9):803-11
references: 12845606
references: Proc Natl Acad Sci U S A. 2004 Jun 29;101(26):9879-84
references: 15159549
references: Nucleic Acids Res. 1997 Sep 1;25(17):3389-402
references: 9254694
references: Eur J Biochem. 2002 Feb;269(3):915-22
references: 11846793
references: J Cell Biol. 1989 May;108(5):1657-64
references: 2654139
references: J Biol Chem. 2000 Jun 30;275(26):20168-78
references: 10787422
references: Can J Microbiol. 1970 Jul;16(7):605-8
references: 4319470
references: Fungal Genet Biol. 2006 Jul;43(7):476-89
references: 16603391
references: J Mol Biol. 2003 Jul 4;330(2):443-56
references: 12823981
references: FEMS Microbiol Lett. 2002 Nov 19;217(1):9-14
references: 12445639
references: Fungal Genet Biol. 2006 Aug;43(8):593-603
references: 16698295
references: Eukaryot Cell. 2002 Oct;1(5):719-24
references: 12455691
references: Anal Biochem. 1999 May 15;270(1):41-9
references: 10328763
references: Nature. 1970 Aug 15;227(5259):680-5
references: 5432063
references: Fungal Genet Biol. 2003 Dec;40(3):225-33
references: 14599890
references: Curr Genet. 1992 Jan;21(1):43-7
references: 1531185
references: Mol Microbiol. 2003 Mar;47(6):1601-12
references: 12622815
references: Mol Plant Microbe Interact. 1998 May;11(5):404-12
references: 9574508
references: EMBO J. 2001 Sep 17;20(18):5079-90
references: 11566873
references: Fungal Genet Biol. 2007 Mar;44(3):187-98
references: 17005424
references: Appl Environ Microbiol. 2002 Sep;68(9):4574-82
references: 12200316
references: Mol Gen Genet. 1995 Apr 10;247(1):95-104
references: 7715608
references: Arch Microbiol. 1990;153(5):485-9
references: 2339955
references: Fungal Genet Biol. 2003 Jul;39(2):168-75
references: 12781675
references: Plant Cell. 1994 May;6(5):761-772
references: 12244257
references: FEMS Yeast Res. 2002 Aug;2(3):315-25
references: 12702281
references: EMBO J. 1982;1(1):53-8
references: 16453407
references: Curr Genet. 2004 Jan;44(6):305-16
references: 14569415
references: New Phytol. 2005 Jul;167(1):229-38
references: 15948845
references: Cell Microbiol. 2007 Jul;9(7):1716-29
references: 17331157
references: Fungal Genet Biol. 2004 Feb;41(2):157-67
references: 14732262
references: Anal Biochem. 1997 Feb 15;245(2):154-60
references: 9056205
references: J Mol Biol. 2003 May 2;328(3):567-79
references: 12706717
references: Appl Microbiol Biotechnol. 2000 Aug;54(2):141-52
references: 10968625
references: Fungal Genet Biol. 2001 Jun;33(1):15-23
references: 11407882
references: Trends Plant Sci. 2002 Jan;7(1):12-3
references: 11804821
references: Arch Microbiol. 1998 Oct;170(5):370-6
references: 9818356
references: J Biol Chem. 1993 Apr 5;268(10):7315-22
references: 8463266