title: Deficiency of a cytosolic ascorbate peroxidase associated with chilling tolerance in soybean.
abstract: We investigated the isozyme profiles of antioxidant enzymes in cultivars and lines with different seed productivity in cool climate conditions as a step towards understanding the physiological and genetical mechanisms underlying chilling tolerance in soybean. While no difference in superoxide dismutase, or catalase isozyme profiles was observed among the cultivars and lines tested, we found polymorphism in the ascorbate peroxidase isozyme profile; there were two types, with or without a cytosolic isoform (APX1). The cultivars and lines lacking APX1 proved more tolerant to chilling temperatures, as evaluated by yielding ability. The genotype-dependent deficiency of APX1 was consistent in plants and tissues under various oxidative stress conditions including the exposure to low-temperatures. In addition, the genetic analysis of progeny derived from crossing between cultivars differing in the isozyme profile indicated that the APX1 deficiency is controlled by a single recessive gene (apx1), and is inherited independently of the genes that have previously been identified for their association with chilling tolerance. Molecular and linkage analyses suggested that the variant gene of the APX1-absent genotype coding for a cytosolic APX, which contained a single nucleotide substitution and a single nucleotide deletion in the coding region, is responsible for the genotype-dependent deficiency of APX1. The association of APX1 deficiency with chilling tolerance is discussed in detail.
authors.affiliation: National Agricultural Research Center for Hokkaido Region (NARCH), Hitsujigaoka, Sapporo, Hokkaido 062-8555, Japan. funazki@affrc.go.jp
authors.forename: H
authors.initials: H
authors.lastname: Funatsuki
authors.forename: H
authors.initials: H
authors.lastname: Kurosaki
authors.forename: T
authors.initials: T
authors.lastname: Murakami
authors.forename: S
authors.initials: S
authors.lastname: Matsuba
authors.forename: K
authors.initials: K
authors.lastname: Kawaguchi
authors.forename: S
authors.initials: S
authors.lastname: Yumoto
authors.forename: Y
authors.initials: Y
authors.lastname: Sato
mesh_terms: D000595:Amino Acid Sequence; D060387:Ascorbate Peroxidases; D015153:Blotting, Western; D002374:Catalase / Q000378:metabolism; D003080:Cold Temperature; D003600:Cytosol; D017931:DNA Primers / Q000737:chemistry; D018744:DNA, Plant / Q000235:genetics / Q000378:metabolism; D017353:Gene Deletion; D018506:Gene Expression Regulation, Plant; D014644:Genetic Variation; D005838:Genotype; D007527:Isoenzymes; D008969:Molecular Sequence Data; D018384:Oxidative Stress; D010544:Peroxidases / Q000172:deficiency* / Q000235:genetics / Q000378:metabolism; D010940:Plant Proteins; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D017386:Sequence Homology, Amino Acid; D015222:Sodium Channels / Q000172:deficiency / Q000235:genetics* / Q000378:metabolism; D013025:Glycine max / Q000201:enzymology* / Q000254:growth & development* / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D017931:DNA Primers; D018744:DNA, Plant; D007527:Isoenzymes; D010940:Plant Proteins; D015222:Sodium Channels; D010544:Peroxidases; D060387:Ascorbate Peroxidases; D002374:Catalase; D013482:Superoxide Dismutase