title: A map-based cloning strategy employing a residual heterozygous line reveals that the GIGANTEA gene is involved in soybean maturity and flowering.
abstract: Flowering is indicative of the transition from vegetative to reproductive phase, a critical event in the life cycle of plants. In soybean (Glycine max), a flowering quantitative trait locus, FT2, corresponding to the maturity locus E2, was detected in recombinant inbred lines (RILs) derived from the varieties "Misuzudaizu" (ft2/ft2; JP28856) and "Moshidou Gong 503" (FT2/FT2; JP27603). A map-based cloning strategy using the progeny of a residual heterozygous line (RHL) from the RIL was employed to isolate the gene responsible for this quantitative trait locus. A GIGANTEA ortholog, GmGIa (Glyma10g36600), was identified as a candidate gene. A common premature stop codon at the 10th exon was present in the Misuzudaizu allele and in other near isogenic lines (NILs) originating from Harosoy (e2/e2; PI548573). Furthermore, a mutant line harboring another premature stop codon showed an earlier flowering phenotype than the original variety, Bay (E2/E2; PI553043). The e2/e2 genotype exhibited elevated expression of GmFT2a, one of the florigen genes that leads to early flowering. The effects of the E2 allele on flowering time were similar among NILs and constant under high (43°N) and middle (36°N) latitudinal regions in Japan. These results indicate that GmGIa is the gene responsible for the E2 locus and that a null mutation in GmGIa may contribute to the geographic adaptation of soybean.
authors.affiliation: National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Watanabe
authors.forename: Zhengjun
authors.initials: Z
authors.lastname: Xia
authors.forename: Rumiko
authors.initials: R
authors.lastname: Hideshima
authors.forename: Yasutaka
authors.initials: Y
authors.lastname: Tsubokura
authors.forename: Shusei
authors.initials: S
authors.lastname: Sato
authors.forename: Naoki
authors.initials: N
authors.lastname: Yamanaka
authors.forename: Ryoji
authors.initials: R
authors.lastname: Takahashi
authors.forename: Toyoaki
authors.initials: T
authors.lastname: Anai
authors.forename: Satoshi
authors.initials: S
authors.lastname: Tabata
authors.forename: Keisuke
authors.initials: K
authors.lastname: Kitamura
authors.forename: Kyuya
authors.initials: K
authors.lastname: Harada
mesh_terms: D000064:Acclimatization / Q000235:genetics; D000531:Altitude; D054458:Amplified Fragment Length Polymorphism Analysis; D002874:Chromosome Mapping; D032461:Chromosomes, Plant / Q000235:genetics; D003001:Cloning, Molecular / Q000379:methods*; D018744:DNA, Plant / Q000737:chemistry / Q000235:genetics; D035264:Flowers / Q000235:genetics* / Q000254:growth & development; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D006579:Heterozygote; D008126:Lod Score; D008969:Molecular Sequence Data; D009154:Mutation; D010802:Phylogeny; D010940:Plant Proteins / Q000145:classification / Q000235:genetics*; D040641:Quantitative Trait Loci / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D030262:Soybean Proteins / Q000235:genetics; D013025:Glycine max / Q000235:genetics* / Q000254:growth & development; D013997:Time Factors
chemical_list: D018744:DNA, Plant; D010940:Plant Proteins; D030262:Soybean Proteins