title: DEAR1, a transcriptional repressor of DREB protein that mediates plant defense and freezing stress responses in Arabidopsis.
abstract: Plants have evolved intricate mechanisms to respond and adapt to a wide variety of biotic and abiotic stresses in their environment. The Arabidopsis DEAR1 (DREB and EAR motif protein 1; At3g50260) gene encodes a protein containing significant homology to the DREB1/CBF (dehydration-responsive element binding protein 1/C-repeat binding factor) domain and the EAR (ethylene response factor-associated amphiphilic repression) motif. We show here that DEAR1 mRNA accumulates in response to both pathogen infection and cold treatment. Transgenic Arabidopsis overexpressing DEAR1 (DEAR1ox) showed a dwarf phenotype and lesion-like cell death, together with constitutive expression of PR genes and accumulation of salicylic acid. DEAR1ox also showed more limited P. syringae pathogen growth compared to wild-type, consistent with an activated defense phenotype. In addition, transient expression experiments revealed that the DEAR1 protein represses DRE/CRT (dehydration-responsive element/C-repeat)-dependent transcription, which is regulated by low temperature. Furthermore, the induction of DREB1/CBF family genes by cold treatment was suppressed in DEAR1ox, leading to a reduction in freezing tolerance. These results suggest that DEAR1 has an upstream regulatory role in mediating crosstalk between signaling pathways for biotic and abiotic stress responses.
authors.affiliation: Faculty of Advanced Life Science, Graduate School of Life Science, Hokkaido University, Kita-ku N10-W8, Sapporo, 060-0810, Japan. ttsutsui@sci.hokudai.ac.jp
authors.forename: Tomokazu
authors.initials: T
authors.lastname: Tsutsui
authors.forename: Wataru
authors.initials: W
authors.lastname: Kato
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Asada
authors.forename: Kaori
authors.initials: K
authors.lastname: Sako
authors.forename: Takeo
authors.initials: T
authors.lastname: Sato
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Sonoda
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kidokoro
authors.forename: Kazuko
authors.initials: K
authors.lastname: Yamaguchi-Shinozaki
authors.forename: Masanori
authors.initials: M
authors.lastname: Tamaoki
authors.forename: Keita
authors.initials: K
authors.lastname: Arakawa
authors.forename: Takanari
authors.initials: T
authors.lastname: Ichikawa
authors.forename: Miki
authors.initials: M
authors.lastname: Nakazawa
authors.forename: Motoaki
authors.initials: M
authors.lastname: Seki
authors.forename: Kazuo
authors.initials: K
authors.lastname: Shinozaki
authors.forename: Minami
authors.initials: M
authors.lastname: Matsui
authors.forename: Akira
authors.initials: A
authors.lastname: Ikeda
authors.forename: Junji
authors.initials: J
authors.lastname: Yamaguchi
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics*; D003001:Cloning, Molecular; D005615:Freezing; D020869:Gene Expression Profiling; D008969:Molecular Sequence Data; D012097:Repressor Proteins / Q000737:chemistry / Q000502:physiology*; D017386:Sequence Homology, Amino Acid; D013312:Stress, Physiological; D014157:Transcription Factors / Q000235:genetics*; D014158:Transcription, Genetic / Q000502:physiology*
chemical_list: D029681:Arabidopsis Proteins; C114578:DREB1A protein, Arabidopsis; D012097:Repressor Proteins; D014157:Transcription Factors