title: Ethylene levels are regulated by a plant encoded 1-aminocyclopropane-1-carboxylic acid deaminase.
abstract: Control of the levels of the plant hormone ethylene is crucial in the regulation of many developmental processes and stress responses. Ethylene production can be controlled by altering endogenous levels of 1-aminocyclopropane-1-carboxylic acid (ACC), the immediate precursor to ethylene or by altering its conversion to ethylene. ACC is known to be irreversibly broken down by bacterial or fungal ACC deaminases (ACDs). Sequence analysis revealed two putative ACD genes encoded for in the genome of Arabidopsis thaliana (A. thaliana) and we detected ACD activity in plant extracts. Expression of one of these A. thaliana genes (AtACD1) in bacteria indicated that it had ACD activity. Moreover, transgenic plants harboring antisense constructs of the gene decreased ACD activity to 70% of wild-type (WT) levels, displayed an increased sensitivity to ACC and produced significantly more ethylene. Taken together, these results show that AtACD1 can act as a regulator of ACC levels in A. thaliana.
authors.affiliation: Department of Biology, Queen's University, Kingston, Ontario, Canada K7L 3N6.
authors.forename: Lisa
authors.initials: L
authors.lastname: McDonnell
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Plett
authors.forename: Sara
authors.initials: S
authors.lastname: Andersson-Gunnerås
authors.forename: Christopher
authors.initials: C
authors.lastname: Kozela
authors.forename: Jasper
authors.initials: J
authors.lastname: Dugardeyn
authors.forename: Dominique
authors.initials: D
authors.lastname: Van Der Straeten
authors.forename: Bernard R
authors.initials: BR
authors.lastname: Glick
authors.forename: Björn
authors.initials: B
authors.lastname: Sundberg
authors.forename: Sharon
authors.initials: S
authors.lastname: Regan
mesh_terms: D000595:Amino Acid Sequence; D000598:Amino Acids, Cyclic / Q000378:metabolism; D051017:Apoptosis Regulatory Proteins / Q000235:genetics / Q000378:metabolism; D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D019755:Carbon-Carbon Lyases / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000378:metabolism; D005030:Ethylenes / Q000096:biosynthesis*; D018506:Gene Expression Regulation, Plant; D008969:Molecular Sequence Data; D010105:Oxygenases / Q000235:genetics / Q000378:metabolism; D010937:Plant Growth Regulators / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000201:enzymology / Q000235:genetics; D032107:Populus / Q000201:enzymology / Q000235:genetics; D012680:Sensitivity and Specificity; D016415:Sequence Alignment
chemical_list: D000598:Amino Acids, Cyclic; D051017:Apoptosis Regulatory Proteins; D029681:Arabidopsis Proteins; D005030:Ethylenes; D010937:Plant Growth Regulators; C023863:1-aminocyclopropane-1-carboxylic acid; C036216:ethylene; C482919:ACD1 protein, Arabidopsis; D010105:Oxygenases; C033634:1-aminocyclopropane-1-carboxylate deaminase; D019755:Carbon-Carbon Lyases