title: Jasmonate signaling is activated in the very early stages of iron deficiency responses in rice roots.
abstract: Under low iron availability, plants induce the expression of various genes involved in iron uptake and translocation at the transcriptional level. This iron deficiency response is affected by various plant hormones, but the roles of jasmonates in this response are not well-known. We investigated the involvement of jasmonates in rice iron deficiency responses. High rates of jasmonate-inducible genes were induced during the very early stages of iron deficiency treatment in rice roots. Many jasmonate-inducible genes were also negatively regulated by the ubiquitin ligases OsHRZ1 and OsHRZ2 and positively regulated by the transcription factor IDEF1. Ten out of 35 genes involved in jasmonate biosynthesis and signaling were rapidly induced at 3 h of iron deficiency treatment, and this induction preceded that of known iron deficiency-inducible genes involved in iron uptake and translocation. Twelve genes involved in jasmonate biosynthesis and signaling were also upregulated in HRZ-knockdown roots. Endogenous concentrations of jasmonic acid and jasmonoyl isoleucine tended to be rapidly increased in roots in response to iron deficiency treatment, whereas these concentrations were higher in HRZ-knockdown roots under iron-sufficient conditions. Analysis of the jasmonate-deficient cpm2 mutant revealed that jasmonates repress the expression of many iron deficiency-inducible genes involved in iron uptake and translocation under iron sufficiency, but this repression is partly canceled under an early stage of iron deficiency. These results indicate that jasmonate signaling is activated during the very early stages of iron deficiency, which is partly regulated by IDEF1 and OsHRZs.
authors.affiliation: Japan Science and Technology Agency, PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama, 332-0012, Japan. abkoba@ishikawa-pu.ac.jp.|Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, 1-308 Suematsu, Nonoichi, Ishikawa, 921-8836, Japan. abkoba@ishikawa-pu.ac.jp.
authors.forename: Takanori
authors.initials: T
authors.lastname: Kobayashi
authors.affiliation: Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan.
authors.forename: Reiko Nakanishi
authors.initials: RN
authors.lastname: Itai
authors.affiliation: Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, 1-308 Suematsu, Nonoichi, Ishikawa, 921-8836, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Senoura
authors.affiliation: Graduate School of Science, Tohoku University, 6-3 Aramaki-aza Aoba, Aoba-ku, Sendai, 980-8578, Japan.
authors.forename: Takaya
authors.initials: T
authors.lastname: Oikawa
authors.affiliation: Graduate School of Science, Tohoku University, 6-3 Aramaki-aza Aoba, Aoba-ku, Sendai, 980-8578, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Ishimaru
authors.affiliation: Graduate School of Science, Tohoku University, 6-3 Aramaki-aza Aoba, Aoba-ku, Sendai, 980-8578, Japan.
authors.forename: Minoru
authors.initials: M
authors.lastname: Ueda
authors.affiliation: Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan.
authors.forename: Hiromi
authors.initials: H
authors.lastname: Nakanishi
authors.affiliation: Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, 1-308 Suematsu, Nonoichi, Ishikawa, 921-8836, Japan.
authors.forename: Naoko K
authors.initials: NK
authors.lastname: Nishizawa
mesh_terms: D003517:Cyclopentanes / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D055785:Gene Knockdown Techniques; D017343:Genes, Plant; D000090463:Iron Deficiencies; D008954:Models, Biological; D012275:Oryza / Q000235:genetics / Q000378:metabolism*; D054883:Oxylipins / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics; D014158:Transcription, Genetic
chemical_list: D003517:Cyclopentanes; D054883:Oxylipins; D010940:Plant Proteins; D012333:RNA, Messenger; C011006:jasmonic acid
keywords: HRZ; IDEF1; Iron deficiency; Jasmonates; Rice; Ubiquitin ligase