title: Low glutathione regulates gene expression and the redox potentials of the nucleus and cytosol in Arabidopsis thaliana.
abstract: Reduced glutathione (GSH) is considered to exert a strong influence on cellular redox homeostasis and to regulate gene expression, but these processes remain poorly characterized. Severe GSH depletion specifically inhibited root meristem development, while low root GSH levels decreased lateral root densities. The redox potential of the nucleus and cytosol of Arabidopsis thaliana roots determined using roGFP probes was between -300 and -320 mV. Growth in the presence of the GSH-synthesis inhibitor buthionine sulfoximine (BSO) increased the nuclear and cytosolic redox potentials to approximately -260 mV. GSH-responsive genes including transcription factors (SPATULA, MYB15, MYB75), proteins involved in cell division, redox regulation (glutaredoxinS17, thioredoxins, ACHT5 and TH8) and auxin signalling (HECATE), were identified in the GSH-deficient root meristemless 1-1 (rml1-1) mutant, and in other GSH-synthesis mutants (rax1-1, cad2-1, pad2-1) as well as in the wild type following the addition of BSO. Inhibition of auxin transport had no effect on organ GSH levels, but exogenous auxin decreased the root GSH pool. We conclude that GSH depletion significantly increases the redox potentials of the nucleus and cytosol, and causes arrest of the cell cycle in roots but not shoots, with accompanying transcript changes linked to altered hormone responses, but not oxidative stress.
authors: Centre for Plant Sciences, School of Biology, University of Leeds, Leeds, LS2 9JT, UK.
authors: Daniel
authors: D
authors: Schnaubelt
authors: Guillaume
authors: G
authors: Queval
authors: Yingping
authors: Y
authors: Dong
authors: Pedro
authors: P
authors: Diaz-Vivancos
authors: Matome Eugene
authors: ME
authors: Makgopa
authors: Gareth
authors: G
authors: Howell
authors: Ambra
authors: A
authors: De Simone
authors: Juan
authors: J
authors: Bai
authors: Matthew A
authors: MA
authors: Hannah
authors: Christine H
authors: CH
authors: Foyer
mesh_terms: D000040:Abscisic Acid / Q000235:genetics / Q000378:metabolism; D017360:Arabidopsis / Q000166:cytology* / Q000187:drug effects / Q000235:genetics*; D002453:Cell Cycle / Q000187:drug effects / Q000235:genetics; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism*; D003600:Cytosol / Q000187:drug effects / Q000378:metabolism*; D005030:Ethylenes / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000187:drug effects*; D017343:Genes, Plant; D005978:Glutathione / Q000494:pharmacology*; D019803:Glutathione Disulfide / Q000378:metabolism; D007210:Indoleacetic Acids / Q000494:pharmacology; D018519:Meristem / Q000166:cytology / Q000187:drug effects / Q000235:genetics; D010084:Oxidation-Reduction / Q000187:drug effects; D010641:Phenotype; D010797:Phthalimides / Q000494:pharmacology; D018520:Plant Shoots / Q000187:drug effects / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D013312:Stress, Physiological / Q000187:drug effects / Q000235:genetics; D013879:Thioredoxins / Q000378:metabolism
chemical_list: D005030:Ethylenes; D007210:Indoleacetic Acids; D010797:Phthalimides; D012333:RNA, Messenger; C002687:alpha-naphthylphthalamic acid; D013879:Thioredoxins; D000040:Abscisic Acid; C036216:ethylene; D005978:Glutathione; D019803:Glutathione Disulfide
keywords: auxin signalling; cell cycle; glutaredoxins; lateral root densities; nuclei; redox signalling; root meristem; thioredoxins