title: A novel mitochondrial DnaJ/Hsp40 family protein BIL2 promotes plant growth and resistance against environmental stress in brassinosteroid signaling.
abstract: Plant steroid hormones, brassinosteroids, are essential for growth, development and responses to environmental stresses in plants. Although BR signaling proteins are localized in many organelles, i.e., the plasma membrane, nuclei, endoplasmic reticulum and vacuole, the details regarding the BR signaling pathway from perception at the cellular membrane receptor BRASSINOSTEROID INSENSITIVE 1 (BRI1) to nuclear events include several steps. Brz (Brz220) is a specific inhibitor of BR biosynthesis. In this study, we used Brz-mediated chemical genetics to identify Brz-insensitive-long hypocotyls 2-1D (bil2-1D). The BIL2 gene encodes a mitochondrial-localized DnaJ/Heat shock protein 40 (DnaJ/Hsp40) family, which is involved in protein folding. BIL2-overexpression plants (BIL2-OX) showed cell elongation under Brz treatment, increasing the growth of plant inflorescence and roots, the regulation of BR-responsive gene expression and suppression against the dwarfed BRI1-deficient mutant. BIL2-OX also showed resistance against the mitochondrial ATPase inhibitor oligomycin and higher levels of exogenous ATP compared with wild-type plants. BIL2 participates in resistance against salinity stress and strong light stress. Our results indicate that BIL2 induces cell elongation during BR signaling through the promotion of ATP synthesis in mitochondria.
authors.affiliation: RIKEN Advanced Science Institute, 2-1 Hirosawa, Saitama, Wako 351-0198, Japan.
authors.forename: Davaapurev
authors.initials: D
authors.lastname: Bekh-Ochir
authors.forename: Setsuko
authors.initials: S
authors.lastname: Shimada
authors.forename: Ayumi
authors.initials: A
authors.lastname: Yamagami
authors.forename: Satomi
authors.initials: S
authors.lastname: Kanda
authors.forename: Kenji
authors.initials: K
authors.lastname: Ogawa
authors.forename: Miki
authors.initials: M
authors.lastname: Nakazawa
authors.forename: Minami
authors.initials: M
authors.lastname: Matsui
authors.forename: Masaaki
authors.initials: M
authors.lastname: Sakuta
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Osada
authors.forename: Tadao
authors.initials: T
authors.lastname: Asami
authors.forename: Takeshi
authors.initials: T
authors.lastname: Nakano
mesh_terms: D000255:Adenosine Triphosphate / Q000096:biosynthesis; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D060406:Brassinosteroids / Q000378:metabolism*; D004777:Environment; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000187:drug effects / Q000528:radiation effects; D017343:Genes, Plant / Q000235:genetics; D050956:HSP40 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism; D008027:Light; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism* / Q000528:radiation effects; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D009928:Organ Specificity / Q000187:drug effects / Q000235:genetics / Q000528:radiation effects; D010641:Phenotype; D063245:Plant Development / Q000187:drug effects / Q000235:genetics / Q000528:radiation effects; D034622:RNA Interference / Q000187:drug effects / Q000528:radiation effects; D055049:Salt Tolerance / Q000187:drug effects / Q000235:genetics / Q000528:radiation effects; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics / Q000528:radiation effects; D012965:Sodium Chloride / Q000494:pharmacology; D013312:Stress, Physiological / Q000187:drug effects / Q000235:genetics / Q000528:radiation effects
chemical_list: D029681:Arabidopsis Proteins; D060406:Brassinosteroids; D050956:HSP40 Heat-Shock Proteins; D012965:Sodium Chloride; D000255:Adenosine Triphosphate