Salt-specific regulation of the cytosolic O-acetylserine(thiol)lyase gene from Arabidopsis thaliana is dependent on abscisic acid.
The expression of Atcys-3A gene coding for cytosolic O-acetylserine(thiol)lyase, a key enzyme in cysteine biosynthesis, from Arabidopsis thaliana is significantly induced by exposure to salt and heavy-metal stresses. Addition of NaCl to mature plants induced a rapid accumulation of the mRNA throughout the leaf lamina and roots, and later on in stems, being mainly restricted to vascular tissues. The salt-specific regulation of Atcys-3A was also mediated by abscisic acid (ABA) since: (1) exogenous addition of ABA to the culture medium mimicked the salt-induced plant response by raising the level of Atcys-3A transcript, and (2) Arabidopsis mutants aba-1 and abi2-1 were not able to respond to NaCl. Our results suggest that a high rate of cysteine biosynthesis is required in Arabidopsis under salt stress necessary for a plant protection or adaptation mechanism. This hypothesis was supported by the observation that intracellular levels of cysteine and glutathione increased up to 3-fold after salt treatment.
Barroso
C
C
Instituto de Bioquímica Vegetal y Fotosíntesis, Centro de Investigaciones Científicas Isla de la Cartuja, CSIC and Universidad de Sevilla, Spain.
Romero
L C
LC
Cejudo
F J
FJ
Vega
J M
JM
Gotor
C
C
D000040:Abscisic Acid / Q000494:pharmacology*; D017360:Arabidopsis / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics; D019757:Carbon-Oxygen Lyases / Q000235:genetics*; D003547:Cysteine Synthase; D003600:Cytosol / Q000201:enzymology; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant / Q000235:genetics; D017403:In Situ Hybridization; D019216:Metals, Heavy / Q000494:pharmacology; D009097:Multienzyme Complexes; D010937:Plant Growth Regulators / Q000494:pharmacology*; D012333:RNA, Messenger / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D018749:RNA, Plant / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D012965:Sodium Chloride / Q000494:pharmacology*; D014018:Tissue Distribution
D019216:Metals, Heavy; D009097:Multienzyme Complexes; D010937:Plant Growth Regulators; D012333:RNA, Messenger; D018749:RNA, Plant; D029701:Saccharomyces cerevisiae Proteins; D012965:Sodium Chloride; D000040:Abscisic Acid; D003547:Cysteine Synthase; C103381:MET17 protein, S cerevisiae; C018725:O-acetylhomoserine (thiol)-lyase; D019757:Carbon-Oxygen Lyases