title: Assessment of salinity-induced photorespiratory glycolate metabolism in Anabaena sp. PCC 7120.
abstract: This paper reports an investigation of salinity-induced glycolate metabolism in the cyanobacterium Anabaena sp. PCC 7120 (hereafter Anabaena PCC 7120). Quantitative analysis of transcripts for the photosynthesis-associated genes encoding ribulose-1,5-bisphosphate carboxylase oxygenase (Rubisco), phosphoribulokinase and transketolase, as well as those involved in glycolate metabolism (phosphoglycolate phosphatase, glycolate oxidase, alanine-glyoxylate aminotransferase and serine hydroxymethyltransferase) was performed. The expression of all investigated photosynthesis-associated genes except Rubisco was downregulated after 24 h NaCl treatment. However, under the same conditions, the transcripts encoding enzymes involved in glycolate metabolism were overexpressed. This was further confirmed by the quantitative analysis of the intermediates involved in glycolate metabolism. The intracellular levels of organic acids (glyceric, glycolic and glyoxylic acids) and amino acids (glycine and serine) were elevated in salt-treated cells as compared to those in the control cells. Transcriptional inhibition of photosynthesis-associated genes, and upregulation of genes and enhanced synthesis of intermediates associated with glycolate metabolism, indicate the occurrence of this photorespiratory metabolic pathway metabolism in Anabaena PCC 7120 under salt stress.
authors.affiliation: School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW 2052, Australia.|Department of Botany, School of Life Sciences, Mizoram University, Tanhril Campus, Aizawl 796004, India.
authors.forename: Ashish Kumar
authors.initials: AK
authors.lastname: Srivastava
authors.affiliation: School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW 2052, Australia.
authors.forename: Ralitza
authors.initials: R
authors.lastname: Alexova
authors.affiliation: School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW 2052, Australia.
authors.forename: Young Jae
authors.initials: YJ
authors.lastname: Jeon
authors.affiliation: School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW 2052, Australia.
authors.forename: Gurjeet S
authors.initials: GS
authors.lastname: Kohli
authors.affiliation: School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW 2052, Australia.
authors.forename: Brett A
authors.initials: BA
authors.lastname: Neilan
mesh_terms: D017033:Anabaena / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D006016:Glycolates / Q000378:metabolism*; D018869:Heat-Shock Response; D008969:Molecular Sequence Data; D010101:Oxygen Consumption; D010788:Photosynthesis; D012273:Ribulose-Bisphosphate Carboxylase / Q000235:genetics / Q000378:metabolism; D017422:Sequence Analysis, DNA; D012965:Sodium Chloride / Q000494:pharmacology*
chemical_list: D001426:Bacterial Proteins; D006016:Glycolates; C031149:glycolic acid; D012965:Sodium Chloride; D012273:Ribulose-Bisphosphate Carboxylase