title: Mutations inArgonaute5Illuminate Epistatic Interactions of theK1andILoci Leading to Saddle Seed Color Patterns inGlycine max.
abstract: The soybean (Glycine max) seed coat has distinctive, genetically programmed patterns of pigmentation, and the recessivek1mutation can epistatically overcome the dominantIandiialleles, which inhibit seed color by producing small interfering RNAs (siRNAs) targetingchalcone synthase(CHS) mRNAs. Small RNA sequencing of dissected regions of immature seed coats demonstrated thatCHSsiRNA levels cause the patterns produced by theiiandikalleles of theIlocus, which restrict pigment to the hilum or saddle region of the seed coat, respectively. To identify theK1locus, we compared RNA-seq data from dissected regions of two Clark isolines having similar saddle phenotypes mediated byCHSsiRNAs but different genotypes (homozygousikK1versus homozygousiik1). By examining differentially expressed genes, mapping information, and genome resequencing, we identified a 129-bp deletion in Glyma.11G190900 encoding Argonaute5 (AGO5), a member of the Argonaute family. Amplicon sequencing of several independent saddle pattern mutants from different genetic backgrounds revealed independent lesions affectingAGO5, thus establishing Glyma.11G190900 as theK1locus. Nonfunctional AGO5 fromk1alleles leads to altered distributions ofCHSsiRNAs, thus explaining how thek1mutation reverses the phenotype of the seed coat regions from yellow to pigmented, even in the presence of the normally dominantIoriialleles.
authors.affiliation: Department of Crop Sciences, University of Illinois, Urbana, Illinois 61801.
authors.forename: Young B
authors.initials: YB
authors.lastname: Cho
authors.affiliation: Department of Crop Sciences, University of Illinois, Urbana, Illinois 61801.
authors.forename: Sarah I
authors.initials: SI
authors.lastname: Jones
authors.affiliation: Department of Crop Sciences, University of Illinois, Urbana, Illinois 61801 l-vodkin@illinois.edu.
authors.forename: Lila O
authors.identifier: http://orcid.org/0000-0001-7866-3152
authors.initials: LO
authors.lastname: Vodkin
mesh_terms: D018745:Genome, Plant / Q000235:genetics; D009154:Mutation; D010858:Pigmentation / Q000235:genetics*; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D034741:RNA, Small Interfering / Q000235:genetics; D013025:Glycine max / Q000235:genetics* / Q000378:metabolism*
chemical_list: D010940:Plant Proteins; D034741:RNA, Small Interfering