title: Transposon Tagging of a Male-Sterility, Female-Sterility Gene, St8, Revealed that the Meiotic MER3 DNA Helicase Activity Is Essential for Fertility in Soybean.
abstract: The W4 locus in soybean encodes a dihydroflavonol-4-reductase (DFR2) that regulates pigmentation patterns in flowers and hypocotyl. The mutable w4-m allele that governs variegated flowers has arisen through insertion of a CACTA-type transposable element, Tgm9, in DFR2. In the w4-m line, reversion from variegated to purple flower indicates excision of Tgm9, and its insertion at a new locus. Previously, we have identified a male-sterile, female-sterile mutant among the selfed progenies of a revertant plant carrying only purple flowers. Co-segregation between Tgm9 and the sterility phenotype suggested that the mutant was generated by insertion of Tgm9 at the St8 locus. The transposon was localized to exon 10 of Glyma.16G072300 that shows high identity to the MER3 DNA helicase involved in crossing over. Molecular analysis of fertile branches from two independent revertant plants confirmed precise excision of Tgm9 from the st8 allele, which restored fertility. In soybean, the gene is expressed in flower-buds, trifoliate leaves and stem. Phylogenetic analysis placed St8 in a clade with the Arabidopsis and rice MER3 suggesting that St8 is most likely the orthologous MER3 soybean gene. This study established the utility of Tgm9 in gene identification as well as in forward and reverse genetics studies.
authors.affiliation: Department of Biology, University of Wisconsin-Stevens Point, Stevens Point, Wiconsin, 54481, United States of America.|Department of Agronomy, Iowa State University, Ames, Iowa, 50011, United States of America.
authors.forename: Jordan
authors.initials: J
authors.lastname: Baumbach
authors.affiliation: Department of Agronomy, Iowa State University, Ames, Iowa, 50011, United States of America.
authors.forename: Ramesh N
authors.initials: RN
authors.lastname: Pudake
authors.affiliation: Department of Biology, University of Wisconsin-Stevens Point, Stevens Point, Wiconsin, 54481, United States of America.
authors.forename: Callie
authors.initials: C
authors.lastname: Johnson
authors.affiliation: Department of Biology, University of Wisconsin-Stevens Point, Stevens Point, Wiconsin, 54481, United States of America.
authors.forename: Kaylin
authors.initials: K
authors.lastname: Kleinhans
authors.affiliation: Department of Biology, University of Wisconsin-Stevens Point, Stevens Point, Wiconsin, 54481, United States of America.
authors.forename: Alexandrea
authors.initials: A
authors.lastname: Ollhoff
authors.affiliation: Department of Agronomy, Iowa State University, Ames, Iowa, 50011, United States of America.
authors.forename: Reid G
authors.initials: RG
authors.lastname: Palmer
authors.affiliation: Department of Agronomy, Iowa State University, Ames, Iowa, 50011, United States of America.
authors.forename: Madan K
authors.initials: MK
authors.lastname: Bhattacharyya
authors.affiliation: Department of Biology, University of Wisconsin-Stevens Point, Stevens Point, Wiconsin, 54481, United States of America.|USDA-ARS Salinity Lab., 450 W. Big Springs Rd., Riverside, California, 92507, United States of America.
authors.forename: Devinder
authors.initials: D
authors.lastname: Sandhu
mesh_terms: D000429:Alcohol Oxidoreductases / Q000235:genetics / Q000502:physiology; D016386:Chromosome Walking / Q000379:methods; D004265:DNA Helicases / Q000235:genetics* / Q000502:physiology; D004251:DNA Transposable Elements / Q000235:genetics; D005298:Fertility / Q000235:genetics / Q000502:physiology; D017343:Genes, Plant / Q000235:genetics / Q000502:physiology; D008540:Meiosis / Q000235:genetics / Q000502:physiology; D010802:Phylogeny; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D013025:Glycine max / Q000235:genetics* / Q000502:physiology
chemical_list: D004251:DNA Transposable Elements; D000429:Alcohol Oxidoreductases; C056570:dihydroflavanol 4-reductase; D004265:DNA Helicases