Arabidopsis stress-inducible gene for arginine decarboxylase AtADC2 is required for accumulation of putrescine in salt tolerance.
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.
Urano
Kaoru
K
Laboratory of Plant Molecular Biology, RIKEN Tsukuba Institute, 3-1-1 Koyadai, Tsukuba, Ibaraki 305-0074, Japan.
Yoshiba
Yoshu
Y
Nanjo
Tokihiko
T
Ito
Takuya
T
Yamaguchi-Shinozaki
Kazuko
K
Shinozaki
Kazuo
K
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
D029681:Arabidopsis Proteins; D012965:Sodium Chloride; D002262:Carboxy-Lyases; C019722:arginine decarboxylase; D011700:Putrescine