title: A stress-inducible sulphotransferase sulphonates salicylic acid and confers pathogen resistance in Arabidopsis.
abstract: Sulphonation of small molecules by cytosolic sulphotransferases in mammals is an important process in which endogenous molecules are modified for inactivation/activation of their biological effects. Plants possess large numbers of sulphotransferase genes, but their biological functions are largely unknown. Here, we present a functional analysis of the Arabidopsis sulphotransferase AtSOT12 (At2g03760). AtSOT12 gene expression is strongly induced by salt, and osmotic stress and hormone treatments. The T-DNA knock-out mutant sot12 exhibited hypersensitivity to NaCl and ABA in seed germination, and to salicylic acid (SA) in seedling growth. In vitro enzyme activity assay revealed that AtSOT12 sulphonates SA, and endogenous SA levels suggested that sulphonation of SA positively regulates SA production. Upon challenging with the pathogen Pseudomonas syringae, sot12 mutant and AtSOT12 over-expressing lines accumulate less and more SA, respectively, when compared with wild type. Consistent with the changes in SA levels, the sot12 mutant was more susceptible, while AtSOT12 over-expressing plants are more resistant to pathogen infection. Moreover, pathogen-induced PR gene expression in systemic leaves was significantly enhanced in AtSOT12 over-expressing plants. The role of sulphonation of SA in SA production, mobile signalling and acquired systemic resistance is discussed.
authors.affiliation: Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409, USA.
authors.forename: Dongwon
authors.initials: D
authors.lastname: Baek
authors.forename: Prasanth
authors.initials: P
authors.lastname: Pathange
authors.forename: Jung-Sung
authors.initials: JS
authors.lastname: Chung
authors.forename: Jiafu
authors.initials: J
authors.lastname: Jiang
authors.forename: Liqiong
authors.initials: L
authors.lastname: Gao
authors.forename: Akira
authors.initials: A
authors.lastname: Oikawa
authors.forename: Masami Yokota
authors.initials: MY
authors.lastname: Hirai
authors.forename: Kazuki
authors.initials: K
authors.lastname: Saito
authors.forename: Paul W
authors.initials: PW
authors.lastname: Pare
authors.forename: Huazhong
authors.initials: H
authors.lastname: Shi
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology; D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics / Q000382:microbiology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D007113:Immunity, Innate; D016254:Mutagenesis, Insertional; D009154:Mutation; D010935:Plant Diseases / Q000235:genetics; D044224:Pseudomonas syringae; D020156:Salicylic Acid / Q000378:metabolism*; D012965:Sodium Chloride / Q000494:pharmacology; D015238:Sulfotransferases / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D012965:Sodium Chloride; D000040:Abscisic Acid; D015238:Sulfotransferases; D020156:Salicylic Acid