Abscisic acid modulates polyamine metabolism under water stress in Arabidopsis thaliana

Limited information is available concerning plant signal transduction pathways regulating polyamine (PA) metabolism in response to various abiotic stress conditions. To gain a new insight into this question, we have studied the possible role of abscisic acid (ABA) in the modulation of PA metabolism under water stress conditions in the model plant Arabidopsis thaliana. Transcriptome profiling of the PA-biosynthetic gene family by real-time quantitative reverse transcriptase polymerase chain reaction revealed that arginine decarboxylase 2 (ADC2), spermidine synthase 1 (SPDS1) and spermine synthase (SPMS) genes are highly induced by drought stress, and these responses are mostly impaired in ABA-deficient (aba2-3) and ABA-insensitive (abi1-1) mutants. These data, together with PAcontent analyses, indicate that ABAmodulates PAmetabolism at transcriptional and metabolite level in response to water stress.