title: Isocitrate lyase is required for urediniospore germination of Puccinia striiformis f. sp. tritici.
abstract: The PstICL1 gene, which encodes isocitrate lyase, a key enzyme in the glyoxylate cycle, was cloned and characterized in the biotrophic wheat pathogen Puccinia striiformis f. sp. tritici (Pst). Expression analyses of PstICL1 exhibited high levels of transcripts in ungerminated urediniospores, which showed low isocitrate lyase enzyme activity. In planta, PstICL1 expression was continuously down-regulated upon germination. During the later stages of the infection of wheat, the level of PstICL1 expression was extremely low. The function of PstICL1 was identified via mutant complementation. The expression of PstICL1 in Saccharomyces cerevisiae can complement the defects of the △ICL mutant. Using 3-nitropropionate, we observed that inactivation of isocitrate lyase greatly reduced the germination rate of urediniospores, indicating that PstICL1 plays a key role during Pst germination. Furthermore, analysis of lipid bodies revealed that lipid components continuously enter the germ tube from the urediniospore cell during germ tube elongation. Moreover, during this period, the lipid contents continuously decreased, and the total carbohydrates markedly increased, demonstrating that the lipids are being converted into carbohydrates. These results suggest that PstICL1 is required for Pst germination.
authors.affiliation: College of Life Sciences, State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A&F University, Yangling, 712100, Shaanxi, China, liujie2003@hotmail.com.
authors.forename: Jie
authors.initials: J
authors.lastname: Liu
authors.forename: Qiu-Ling
authors.initials: QL
authors.lastname: Wang
authors.forename: Qing
authors.initials: Q
authors.lastname: Chang
authors.forename: Li-Na
authors.initials: LN
authors.lastname: Han
authors.forename: Guo-Liang
authors.initials: GL
authors.lastname: Pei
authors.forename: Yue-Qing
authors.initials: YQ
authors.lastname: Xue
authors.forename: Lu-Meng
authors.initials: LM
authors.lastname: Jia
authors.forename: Kun
authors.initials: K
authors.lastname: Zhang
authors.forename: Yuan-Yuan
authors.initials: YY
authors.lastname: Duan
authors.forename: Zhen-Sheng
authors.initials: ZS
authors.lastname: Kang
mesh_terms: D001487:Basidiomycota / Q000201:enzymology / Q000254:growth & development*; D003001:Cloning, Molecular; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D018525:Germination; D007522:Isocitrate Lyase / Q000235:genetics* / Q000378:metabolism*; D009574:Nitro Compounds / Q000494:pharmacology; D010802:Phylogeny; D011422:Propionates / Q000494:pharmacology; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics
chemical_list: D005656:Fungal Proteins; D009574:Nitro Compounds; D011422:Propionates; D007522:Isocitrate Lyase; C015392:3-nitropropionic acid
references.citation: Mol Plant Microbe Interact. 2002 Aug;15(8):847-56
references.pmid: 12182343
references.citation: Curr Genet. 1992 Jan;21(1):43-7
references.pmid: 1531185
references.citation: Mutat Res. 2000 Sep 20;453(1):77-82
references.pmid: 11006414
references.citation: Fungal Genet Biol. 2001 Aug;33(3):195-211
references.pmid: 11495576
references.citation: Eur J Biochem. 1992 Mar 15;204(3):983-90
references.pmid: 1551398
references.citation: Infect Immun. 2002 Jun;70(6):2787-95
references.pmid: 12010964
references.citation: J Bacteriol. 1988 Oct;170(10):4528-36
references.pmid: 3049537
references.citation: Science. 1948 Mar 5;107(2775):254-5
references.pmid: 17814729
references.citation: Infect Immun. 2007 Nov;75(11):5313-24
references.pmid: 17724070
references.citation: Plant Mol Biol. 1987 Nov;8(6):471-5
references.pmid: 24301309
references.citation: Mol Microbiol. 2003 Mar;47(6):1523-43
references.pmid: 12622810
references.citation: Med Mycol. 2008 Mar;46(2):125-34
references.pmid: 18324491
references.citation: Mol Microbiol. 2004 Aug;53(4):1065-73
references.pmid: 15306011
references.citation: Fungal Genet Biol. 1997 Jun;21(3):348-63
references.pmid: 9290248
references.citation: FEMS Microbiol Lett. 1998 Nov 15;168(2):159-66
references.pmid: 9835024
references.citation: Plant Cell. 1989 Mar;1(3):293-300
references.pmid: 2535504
references.citation: Microbiology (Reading). 2011 Jan;157(Pt 1):199-208
references.pmid: 20929953
references.citation: Microbiology (Reading). 2009 Oct;155(Pt 10):3166-3175
references.pmid: 19684068
references.citation: J Biochem. 1990 Feb;107(2):262-6
references.pmid: 2361956