title: Genetic control of morphometric diversity in the maize shoot apical meristem.
abstract: The maize shoot apical meristem (SAM) comprises a small pool of stem cells that generate all above-ground organs. Although mutational studies have identified genetic networks regulating SAM function, little is known about SAM morphological variation in natural populations. Here we report the use of high-throughput image processing to capture rich SAM size variation within a diverse maize inbred panel. We demonstrate correlations between seedling SAM size and agronomically important adult traits such as flowering time, stem size and leaf node number. Combining SAM phenotypes with 1.2 million single nucleotide polymorphisms (SNPs) via genome-wide association study reveals unexpected SAM morphology candidate genes. Analyses of candidate genes implicated in hormone transport, cell division and cell size confirm correlations between SAM morphology and trait-associated SNP alleles. Our data illustrate that the microscopic seedling SAM is predictive of adult phenotypes and that SAM morphometric variation is associated with genes not previously predicted to regulate SAM size.
authors.affiliation: Division of Plant Biology, Cornell University, Ithaca, New York 14850, USA.
authors.forename: Samuel
authors.initials: S
authors.lastname: Leiboff
authors.affiliation: Department of Agronomy, Iowa State University, Ames, Iowa 50010, USA.
authors.forename: Xianran
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Agronomy, Iowa State University, Ames, Iowa 50010, USA.
authors.forename: Heng-Cheng
authors.initials: HC
authors.lastname: Hu
authors.affiliation: Division of Plant Biology, Cornell University, Ithaca, New York 14850, USA.
authors.forename: Natalie
authors.initials: N
authors.lastname: Todt
authors.affiliation: Department of Agronomy, Iowa State University, Ames, Iowa 50010, USA.
authors.forename: Jinliang
authors.initials: J
authors.lastname: Yang
authors.affiliation: Department of Agronomy, Iowa State University, Ames, Iowa 50010, USA.
authors.forename: Xiao
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Agronomy, Iowa State University, Ames, Iowa 50010, USA.
authors.forename: Xiaoqing
authors.initials: X
authors.lastname: Yu
authors.affiliation: Department of Agronomy and Plant Genetics, University of Minnesota, St Paul, Minnesota 55108, USA.
authors.forename: Gary J
authors.initials: GJ
authors.lastname: Muehlbauer
authors.affiliation: Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724, USA.
authors.forename: Marja C P
authors.initials: MC
authors.lastname: Timmermans
authors.affiliation: Department of Agronomy, Iowa State University, Ames, Iowa 50010, USA.
authors.forename: Jianming
authors.initials: J
authors.lastname: Yu
authors.affiliation: Department of Agronomy, Iowa State University, Ames, Iowa 50010, USA.
authors.forename: Patrick S
authors.initials: PS
authors.lastname: Schnable
authors.affiliation: Division of Plant Biology, Cornell University, Ithaca, New York 14850, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Scanlon
mesh_terms: D018506:Gene Expression Regulation, Plant; D055106:Genome-Wide Association Study; D018519:Meristem / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D018520:Plant Shoots / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D020641:Polymorphism, Single Nucleotide; D003313:Zea mays / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism