title: Zinc finger protein STOP1 is critical for proton tolerance in Arabidopsis and coregulates a key gene in aluminum tolerance.
abstract: Acid soil syndrome causes severe yield losses in various crop plants because of the rhizotoxicities of ions, such as aluminum (Al(3+)). Although protons (H(+)) could be also major rhizotoxicants in some soil types, molecular mechanisms of their tolerance have not been identified yet. One mutant that was hypersensitive to H(+) rhizotoxicity was isolated from ethyl methanesulfonate mutagenized seeds, and a single recessive mutation was found on chromosome 1. Positional cloning followed by genomic sequence analysis revealed that a missense mutation in the zinc finger domain in a predicted Cys(2)His(2)-type zinc finger protein, namely sensitive to proton rhizotoxicity (STOP)1, is the cause of hypersensitivity to H(+) rhizotoxicity. The STOP1 protein belongs to a functionally unidentified subfamily of zinc finger proteins, which consists of two members in Arabidopsis based on a Blast search. The stop1 mutation resulted in no effects on cadmium, copper, lanthanum, manganese and sodium chloride sensitivitities, whereas it caused hypersensitivity to Al(3+) rhizotoxicity. This stop1 mutant lacked the induction of the AtALMT1 gene encoding a malate transporter, which is concomitant with Al-induced malate exudation. There was no induction of AtALMT1 by Al(3+) treatment in the stop1 mutant. These results indicate that STOP1 plays a critical role in Arabidopsis tolerance to major stress factors in acid soils.
authors.affiliation: BioResources Center, RIKEN, 3-1-1 Koyadai, Tsukuba, Ibaraki 305-0074, Japan. iuchi@brc.riken.jp
authors.forename: Satoshi
authors.initials: S
authors.lastname: Iuchi
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Koyama
authors.forename: Atsuko
authors.initials: A
authors.lastname: Iuchi
authors.forename: Yasufumi
authors.initials: Y
authors.lastname: Kobayashi
authors.forename: Sadako
authors.initials: S
authors.lastname: Kitabayashi
authors.forename: Yuriko
authors.initials: Y
authors.lastname: Kobayashi
authors.forename: Takashi
authors.initials: T
authors.lastname: Ikka
authors.forename: Takashi
authors.initials: T
authors.lastname: Hirayama
authors.forename: Kazuo
authors.initials: K
authors.lastname: Shinozaki
authors.forename: Masatomo
authors.initials: M
authors.lastname: Kobayashi
mesh_terms: D000535:Aluminum / Q000633:toxicity*; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D003001:Cloning, Molecular; D019295:Computational Biology; D017931:DNA Primers; D040461:Gene Components; D018506:Gene Expression Regulation, Plant / Q000235:genetics*; D005816:Genetic Complementation Test; D008293:Malates / Q000378:metabolism; D008969:Molecular Sequence Data; D020125:Mutation, Missense / Q000235:genetics; D027361:Organic Anion Transporters / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D011522:Protons; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D014157:Transcription Factors / Q000235:genetics*; D016335:Zinc Fingers
chemical_list: C512361:ALMT1 protein, Arabidopsis; D029681:Arabidopsis Proteins; D017931:DNA Primers; D008293:Malates; D027361:Organic Anion Transporters; D011522:Protons; C525886:STOP1 protein, Arabidopsis; D014157:Transcription Factors; C030298:malic acid; D000535:Aluminum