title: Genetic control of maize shoot apical meristem architecture.
abstract: The shoot apical meristem contains a pool of undifferentiated stem cells and generates all above-ground organs of the plant. During vegetative growth, cells differentiate from the meristem to initiate leaves while the pool of meristematic cells is preserved; this balance is determined in part by genetic regulatory mechanisms. To assess vegetative meristem growth and genetic control in Zea mays, we investigated its morphology at multiple time points and identified three stages of growth. We measured meristem height, width, plastochron internode length, and associated traits from 86 individuals of the intermated B73 × Mo17 recombinant inbred line population. For meristem height-related traits, the parents exhibited markedly different phenotypes, with B73 being very tall, Mo17 short, and the population distributed between. In the outer cell layer, differences appeared to be related to number of cells rather than cell size. In contrast, B73 and Mo17 were similar in meristem width traits and plastochron internode length, with transgressive segregation in the population. Multiple loci (6-9 for each trait) were mapped, indicating meristem architecture is controlled by many regions; none of these coincided with previously described mutants impacting meristem development. Major loci for height and width explaining 16% and 19% of the variation were identified on chromosomes 5 and 8, respectively. Significant loci for related traits frequently coincided, whereas those for unrelated traits did not overlap. With the use of three near-isogenic lines, a locus explaining 16% of the parental variation in meristem height was validated. Published expression data were leveraged to identify candidate genes in significant regions.
authors.affiliation: Department of Agronomy and Plant Genetics, University of Minnesota, St. Paul, Minnesota 55108.
authors.forename: Addie M
authors.initials: AM
authors.lastname: Thompson
authors.affiliation: Department of Agronomy and Plant Genetics, University of Minnesota, St. Paul, Minnesota 55108.
authors.forename: James
authors.initials: J
authors.lastname: Crants
authors.affiliation: Department of Genetics, Development and Cell Biology, and Agronomy, Iowa State University, Ames, Iowa 50011.
authors.forename: Patrick S
authors.initials: PS
authors.lastname: Schnable
authors.affiliation: Department of Agronomy, Iowa State University, Ames, Iowa 50011.
authors.forename: Jianming
authors.initials: J
authors.lastname: Yu
authors.affiliation: Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724.
authors.forename: Marja C P
authors.initials: MC
authors.lastname: Timmermans
authors.affiliation: Department of Plant Biology, University of Minnesota, Saint Paul, Minnesota 55108.
authors.forename: Nathan M
authors.initials: NM
authors.lastname: Springer
authors.affiliation: Department of Plant Biology, Cornell University, Ithaca, New York 14853.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Scanlon
authors.affiliation: Department of Agronomy and Plant Genetics, University of Minnesota, St. Paul, Minnesota 55108 Department of Plant Biology, University of Minnesota, Saint Paul, Minnesota 55108 muehl003@umn.edu.
authors.forename: Gary J
authors.initials: GJ
authors.lastname: Muehlbauer
mesh_terms: D002874:Chromosome Mapping; D032461:Chromosomes, Plant / Q000235:genetics / Q000378:metabolism; D014644:Genetic Variation; D018519:Meristem / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D010641:Phenotype; D018520:Plant Shoots / Q000235:genetics / Q000378:metabolism; D040641:Quantitative Trait Loci; D003313:Zea mays / Q000235:genetics* / Q000378:metabolism
keywords: IBMRIL; QTL; maize development; plant morphology; shoot apical meristem