title: Natural variation at sympathy for the ligule controls penetrance of the semidominant Liguleless narrow-R mutation in Zea mays.
abstract: Leaf architecture determines plant structural integrity, light harvesting, and economic considerations such as plant density. Ligules, junctions at the leaf sheath and blade in grasses, protect stalks from environmental stresses and, in conjunction with auricles, controls leaf angle. Previous studies in mutants have recessive liguleless mutants (lg1 and lg2) and dominant mutations in knotted1-like homeobox genes (Lg3-O, Lg4, and Kn1) involved in ligule development. Recently, a new semidominant liguleless mutant, Liguleless narrow (Lgn-R), has been characterized in maize that affects ligule and auricle development and results in a narrow leaf phenotype. We show that quantitative genetic variation affects penetrance of Lgn-R. To examine the genetic architecture underlying Lgn-R expressivity, crosses between Lgn-R/+ mutants in a B73 background and intermated B73 x Mo17 recombinant inbred lines were evaluated in multiple years and locations. A single main-effect quantitative trait locus (QTL) on chromosome 1 (sympathy for the ligule; sol) was discovered with a Mo17-contributed allele that suppressed Lgn-R mutant phenotypes. This QTL has a genetic-interaction with a locus on chromosome 7 (lucifer; lcf) for which the B73-contributed allele increases the ability of the sol(Mo17) allele to suppress Lgn-R. Neither of the genetic intervals likely to contain sol or lcf overlap with any current liguleless genes nor with previously identified genome-wide association QTL connected to leaf architecture. Analysis of phenotypes across environments further identified a genotype by enviroment interaction determining the strength of the sol x lcf interaction.
authors.affiliation: Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, Indiana 47907.
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Buescher
authors.affiliation: Plant Gene Expression Center, USDA-ARS, University of California, Berkeley, Albany, California 94710.
authors.forename: Jihyun
authors.initials: J
authors.lastname: Moon
authors.affiliation: Plant Gene Expression Center, USDA-ARS, University of California, Berkeley, Albany, California 94710.
authors.forename: Anne
authors.initials: A
authors.lastname: Runkel
authors.affiliation: Plant Gene Expression Center, USDA-ARS, University of California, Berkeley, Albany, California 94710.
authors.forename: Sarah
authors.initials: S
authors.lastname: Hake
authors.affiliation: Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, Indiana 47907 bdilkes@purdue.edu.
authors.forename: Brian P
authors.initials: BP
authors.lastname: Dilkes
mesh_terms: D000483:Alleles; D050976:Basic-Leucine Zipper Transcription Factors / Q000235:genetics*; D002874:Chromosome Mapping; D032461:Chromosomes, Plant / Q000737:chemistry / Q000378:metabolism; D017343:Genes, Plant; D009876:Operon / Q000235:genetics; D019683:Penetrance; D010641:Phenotype; D018515:Plant Leaves / Q000235:genetics / Q000254:growth & development; D010940:Plant Proteins / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide; D040641:Quantitative Trait Loci; D003313:Zea mays / Q000235:genetics* / Q000254:growth & development
chemical_list: D050976:Basic-Leucine Zipper Transcription Factors; C105241:LG1 protein, Zea mays; C110592:LIGULELESS2 protein, Zea mays; D010940:Plant Proteins
keywords: QTL; development; epistasis; genetic network