title: A Single-Nucleotide Polymorphism in an Endo-1,4-β-Glucanase Gene Controls Seed Coat Permeability in Soybean.
abstract: Physical dormancy, a structural feature of the seed coat known as hard seededness, is an important characteristic for adaptation of plants against unstable and unpredictable environments. To dissect the molecular basis of qHS1, a quantitative trait locus for hard seededness in soybean (Glycine max (L) Merr.), we developed a near-isogenic line (NIL) of a permeable (soft-seeded) cultivar, Tachinagaha, containing a hard-seed allele from wild soybean (G. soja) introduced by successive backcrossings. The hard-seed allele made the seed coat of Tachinagaha more rigid by increasing the amount of β-1,4-glucans in the outer layer of palisade cells of the seed coat on the dorsal side of seeds, known to be a point of entrance of water. Fine-mapping and subsequent expression and sequencing analyses revealed that qHS1 encodes an endo-1,4-β-glucanase. A single-nucleotide polymorphism (SNP) introduced an amino acid substitution in a substrate-binding cleft of the enzyme, possibly reducing or eliminating its affinity for substrates in permeable cultivars. Introduction of the genomic region of qHS1 from the impermeable (hard-seeded) NIL into the permeable cultivar Kariyutaka resulted in accumulation of β-1,4-glucan in the outer layer of palisade cells and production of hard seeds. The SNP allele found in the NIL was further associated with the occurrence of hard seeds in soybean cultivars of various origins. The findings of this and previous studies may indicate that qHS1 is involved in the accumulation of β-1,4-glucan derivatives such as xyloglucan and/or β-(1,3)(1,4)-glucan that reinforce the impermeability of seed coats in soybean.
authors.affiliation: Research Faculty of Agriculture, Hokkaido University, Sapporo, Hokkaido 060-8589, Japan.
authors.forename: Seong-Jin
authors.initials: SJ
authors.lastname: Jang
authors.affiliation: Research Faculty of Agriculture, Hokkaido University, Sapporo, Hokkaido 060-8589, Japan.
authors.forename: Masako
authors.initials: M
authors.lastname: Sato
authors.affiliation: Research Faculty of Agriculture, Hokkaido University, Sapporo, Hokkaido 060-8589, Japan.
authors.forename: Kei
authors.initials: K
authors.lastname: Sato
authors.affiliation: Research Faculty of Agriculture, Hokkaido University, Sapporo, Hokkaido 060-8589, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Jitsuyama
authors.affiliation: Research Faculty of Agriculture, Hokkaido University, Sapporo, Hokkaido 060-8589, Japan.
authors.forename: Kaien
authors.initials: K
authors.lastname: Fujino
authors.affiliation: Research Faculty of Agriculture, Hokkaido University, Sapporo, Hokkaido 060-8589, Japan.
authors.forename: Haruhide
authors.initials: H
authors.lastname: Mori
authors.affiliation: National Institute of Crop Science, 2-1-18 Kannondai, Tsukuba, Ibaraki, 305-8518, Japan.
authors.forename: Ryoji
authors.initials: R
authors.lastname: Takahashi
authors.affiliation: National Institute of Crop Science, 2-1-18 Kannondai, Tsukuba, Ibaraki, 305-8518, Japan.
authors.forename: Eduardo R
authors.initials: ER
authors.lastname: Benitez
authors.affiliation: Northeast Insititute of Geography and Agroecology, Chinese Academy of Sciences, 138 Haping Road, Harbin 150040, China.
authors.forename: Baohui
authors.initials: B
authors.lastname: Liu
authors.affiliation: Research Faculty of Agriculture, Hokkaido University, Sapporo, Hokkaido 060-8589, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Yamada
authors.affiliation: Research Faculty of Agriculture, Hokkaido University, Sapporo, Hokkaido 060-8589, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Abe
mesh_terms: D000483:Alleles; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D001692:Biological Transport; D002480:Cellulase / Q000235:genetics* / Q000378:metabolism; D003433:Crosses, Genetic; D015870:Gene Expression; D005936:Glucans / Q000378:metabolism; D008969:Molecular Sequence Data; D010539:Permeability; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified; D020641:Polymorphism, Single Nucleotide; D040641:Quantitative Trait Loci; D012639:Seeds / Q000235:genetics* / Q000378:metabolism; D016415:Sequence Alignment; D013025:Glycine max / Q000235:genetics* / Q000378:metabolism; D014867:Water / Q000378:metabolism
chemical_list: D005936:Glucans; D010940:Plant Proteins; D014867:Water; C040088:1,4-glucan; D002480:Cellulase