title: A protective role for the polyamine spermine against drought stress in Arabidopsis.
abstract: Cellular polyamine content often changes in response to abiotic stresses. However, its physiological relevance is unknown. We found that an Arabidopsis mutant plant (acl5/spms), which cannot produce spermine, is hypersensitive to high salt. Examination of drought sensitivity of the mutant and comparison with wild type plants indicated hypersensitivity to drought. This phenotype was cured by spermine pretreatment but not by the other polyamines putrescine and spermidine, suggesting that drought-hypersensitivity exhibited by the mutant is due to spermine deficiency. The water loss rate of wild type and mutant plants were similar until 20 min after onset of dehydration stress, but after a longer exposure the rate in mutant plants was higher than in wild type plants. Consistent with this result, the stomata of the mutant leaves remained open while in wild type leaves they closed. Based on the collected data, we discuss a role for spermine in response to drought stress.
authors.affiliation: Graduate School of Life Sciences, Tohoku University, Katahira, Aoba, Sendai, Miyagi 980-8577, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Yamaguchi
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Takahashi
authors.forename: Thomas
authors.initials: T
authors.lastname: Berberich
authors.forename: Akihiko
authors.initials: A
authors.lastname: Imai
authors.forename: Taku
authors.initials: T
authors.lastname: Takahashi
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Michael
authors.forename: Tomonobu
authors.initials: T
authors.lastname: Kusano
mesh_terms: D017360:Arabidopsis / Q000502:physiology*; D003890:Desiccation; D004190:Disasters; D018869:Heat-Shock Response / Q000502:physiology*; D030821:Plants, Genetically Modified; D011073:Polyamines / Q000378:metabolism*; D013096:Spermine / Q000378:metabolism*; D014867:Water / Q000378:metabolism*
chemical_list: D011073:Polyamines; D014867:Water; D013096:Spermine