title: Novel plant immune-priming compounds identified via high-throughput chemical screening target salicylic acid glucosyltransferases in Arabidopsis.
abstract: Plant activators are compounds, such as analogs of the defense hormone salicylic acid (SA), that protect plants from pathogens by activating the plant immune system. Although some plant activators have been widely used in agriculture, the molecular mechanisms of immune induction are largely unknown. Using a newly established high-throughput screening procedure that screens for compounds that specifically potentiate pathogen-activated cell death in Arabidopsis thaliana cultured suspension cells, we identified five compounds that prime the immune response. These compounds enhanced disease resistance against pathogenic Pseudomonas bacteria in Arabidopsis plants. Pretreatments increased the accumulation of endogenous SA, but reduced its metabolite, SA-O-β-d-glucoside. Inducing compounds inhibited two SA glucosyltransferases (SAGTs) in vitro. Double knockout plants that lack both SAGTs consistently exhibited enhanced disease resistance. Our results demonstrate that manipulation of the active free SA pool via SA-inactivating enzymes can be a useful strategy for fortifying plant disease resistance and may identify useful crop protectants.
authors.affiliation: Research Core for Interdisciplinary Sciences, Okayama University, Kita-ku, Okayama 700-8530, Japan. noutoshi@cc.okayama-u.ac.jp
authors.forename: Yoshiteru
authors.initials: Y
authors.lastname: Noutoshi
authors.forename: Masateru
authors.initials: M
authors.lastname: Okazaki
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Kida
authors.forename: Yuta
authors.initials: Y
authors.lastname: Nishina
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Morishita
authors.forename: Takumi
authors.initials: T
authors.lastname: Ogawa
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Suzuki
authors.forename: Daisuke
authors.initials: D
authors.lastname: Shibata
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Jikumaru
authors.forename: Atsushi
authors.initials: A
authors.lastname: Hanada
authors.forename: Yuji
authors.initials: Y
authors.lastname: Kamiya
authors.forename: Ken
authors.initials: K
authors.lastname: Shirasu
mesh_terms: D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics / Q000276:immunology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D016923:Cell Death; D002478:Cells, Cultured; D060467:Disease Resistance; D018506:Gene Expression Regulation, Plant; D055786:Gene Knockout Techniques; D005960:Glucosides / Q000378:metabolism; D005964:Glucosyltransferases / Q000235:genetics* / Q000378:metabolism; D057166:High-Throughput Screening Assays; D016254:Mutagenesis, Insertional; D010935:Plant Diseases / Q000276:immunology* / Q000382:microbiology; D030821:Plants, Genetically Modified; D011549:Pseudomonas / Q000472:pathogenicity*; D012459:Salicylates / Q000378:metabolism; D020156:Salicylic Acid / Q000378:metabolism*; D054852:Small Molecule Libraries
chemical_list: D029681:Arabidopsis Proteins; D005960:Glucosides; D012459:Salicylates; D054852:Small Molecule Libraries; C084746:salicylic acid glucoside; D005964:Glucosyltransferases; D020156:Salicylic Acid