title: Arabidopsis stress-inducible gene for arginine decarboxylase AtADC2 is required for accumulation of putrescine in salt tolerance.
abstract: Arginine decarboxylase (ADC) catalyzes the first step of polyamine (PA) biosynthesis to produce putrescine (Put) from arginine (Arg). One of the 2 Arabidopsis ADC genes, AtADC2, is induced in response to salt stress causing the accumulation of free Put. To analyze the roles of stress-inducible AtADC2 gene and endogenous Put in stress tolerance, we isolated a Ds insertion mutant of AtADC2 gene (adc2-1) and characterized its phenotypes under salt stress. In the adc2-1 mutant, free Put content was reduced to about 25% of that in the control plants and did not increase under salt stress. Furthermore, the adc2-1 mutant was more sensitive to salt stress than the control plants. The stress sensitivity of adc2-1 was recovered by the addition of exogenous Put. These results indicate that endogenous Put plays an important role in salt tolerance in Arabidopsis. AtADC2 is a key gene for the production of Put under not only salinity conditions, but also normal conditions.
authors.affiliation: Laboratory of Plant Molecular Biology, RIKEN Tsukuba Institute, 3-1-1 Koyadai, Tsukuba, Ibaraki 305-0074, Japan.
authors.forename: Kaoru
authors.initials: K
authors.lastname: Urano
authors.forename: Yoshu
authors.initials: Y
authors.lastname: Yoshiba
authors.forename: Tokihiko
authors.initials: T
authors.lastname: Nanjo
authors.forename: Takuya
authors.initials: T
authors.lastname: Ito
authors.forename: Kazuko
authors.initials: K
authors.lastname: Yamaguchi-Shinozaki
authors.forename: Kazuo
authors.initials: K
authors.lastname: Shinozaki
mesh_terms: D000064:Acclimatization; D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics* / Q000502:physiology; D029681:Arabidopsis Proteins / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism; D002262:Carboxy-Lyases / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism; D004790:Enzyme Induction; D015971:Gene Expression Regulation, Enzymologic / Q000235:genetics; D018506:Gene Expression Regulation, Plant / Q000235:genetics; D017343:Genes, Plant / Q000235:genetics; D006651:Histocytochemistry; D009154:Mutation; D010641:Phenotype; D018514:Plant Structures / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism; D011700:Putrescine / Q000096:biosynthesis* / Q000378:metabolism; D012965:Sodium Chloride / Q000494:pharmacology*; D014018:Tissue Distribution
chemical_list: D029681:Arabidopsis Proteins; D012965:Sodium Chloride; D002262:Carboxy-Lyases; C019722:arginine decarboxylase; D011700:Putrescine