title: Putrescine regulating by stress-responsive MAPK cascade contributes to bacterial pathogen defense in Arabidopsis.
abstract: Polyamines in plants are involved in various physiological and developmental processes including abiotic and biotic stress responses. We investigated the expression of ADCs, which are key enzymes in putrescine (Put) biosynthesis, and roles of Put involving defense response in Arabidopsis. The increased expression of ADC1 and ADC2, and the induction of Put were detected in GVG-NtMEK2(DD) transgenic Arabidopsis, whereas, their performance was partially compromised in GVG-NtMEK2(DD)/mpk3 and GVG-NtMEK2(DD)/mpk6 mutant following DEX treatment. The expression of ADC2 was highly induced by Pst DC3000 inoculation, while the transcript levels of ADC1 were slightly up-regulated. Compared to the WT plant, Put content in the adc2 knock-out mutant was reduced after Pst DC3000 inoculation, and showed enhanced susceptibility to pathogen infection. The adc2 mutant exhibited reduced expression of PR-1 after bacterial infection and the growth of the pathogen was about 4-fold more than that in the WT plant. Furthermore, the disease susceptibility of the adc2 mutant was recovered by the addition of exogenous Put. Taken together, these results suggest that Arabidopsis MPK3 and MPK6 play a positive role in the regulation of Put biosynthesis, and that Put contributes to bacterial pathogen defense in Arabidopsis.
authors.affiliation: Department of Plant Biotechnology, College of Agriculture and Life Sciences, Chonnam National University, Gwangju, Republic of Korea.
authors.forename: Su-Hyun
authors.initials: SH
authors.lastname: Kim
authors.forename: Sun-Hwa
authors.initials: SH
authors.lastname: Kim
authors.forename: Seung-Jin
authors.initials: SJ
authors.lastname: Yoo
authors.forename: Kwang-Hyun
authors.initials: KH
authors.lastname: Min
authors.forename: Seung-Hee
authors.initials: SH
authors.lastname: Nam
authors.forename: Baik Ho
authors.initials: BH
authors.lastname: Cho
authors.forename: Kwang-Yeol
authors.initials: KY
authors.lastname: Yang
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism / Q000382:microbiology; D029681:Arabidopsis Proteins / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D020935:MAP Kinase Signaling System; D020929:Mitogen-Activated Protein Kinase Kinases / Q000378:metabolism*; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D009154:Mutation; D010935:Plant Diseases / Q000235:genetics / Q000382:microbiology; D030821:Plants, Genetically Modified; D044224:Pseudomonas syringae; D011700:Putrescine / Q000494:pharmacology*; D013312:Stress, Physiological
chemical_list: D029681:Arabidopsis Proteins; C458516:AtMPK3 protein, Arabidopsis; C436293:MPK6 protein, Arabidopsis; D020928:Mitogen-Activated Protein Kinases; D020929:Mitogen-Activated Protein Kinase Kinases; D011700:Putrescine
keywords: ADC; Arabidopsis MPK3/MPK6; PR-1; Pst DC3000; Putrescine