title: The genetic architecture of shoot-root covariation during seedling emergence of a desert tree, Populus euphratica.
abstract: The coordination of shoots and roots is critical for plants to adapt to changing environments by fine-tuning energy production in leaves and the availability of water and nutrients from roots. To understand the genetic architecture of how these two organs covary during developmental ontogeny, we conducted a mapping experiment using Euphrates poplar (Populus euphratica), a so-called hero tree able to grow in the desert. We geminated intraspecific F1seeds of Euphrates Poplar individually in a tube to obtain a total of 370 seedlings, whose shoot and taproot lengths were measured repeatedly during the early stage of growth. By fitting a growth equation, we estimated asymptotic growth, relative growth rate, the timing of inflection point and duration of linear growth for both shoot and taproot growth. Treating these heterochronic parameters as phenotypes, a univariate mapping model detected 19 heterochronic quantitative trait loci (hQTLs), of which 15 mediate the forms of shoot growth and four mediate taproot growth. A bivariate mapping model identified 11 pleiotropic hQTLs that determine the covariation of shoot and taproot growth. Most QTLs detected reside within the region of candidate genes with various functions, thus confirming their roles in the biochemical processes underlying plant growth.
authors.affiliation: Center for Computational Biology, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, 100083, China.
authors.forename: Miaomiao
authors.initials: M
authors.lastname: Zhang
authors.affiliation: Center for Computational Biology, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, 100083, China.
authors.forename: Wenhao
authors.initials: W
authors.lastname: Bo
authors.affiliation: Center for Computational Biology, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, 100083, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Xu
authors.affiliation: Center for Computational Biology, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, 100083, China.
authors.forename: Huan
authors.initials: H
authors.lastname: Li
authors.affiliation: Center for Computational Biology, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, 100083, China.
authors.forename: Meixia
authors.initials: M
authors.lastname: Ye
authors.affiliation: Center for Computational Biology, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, 100083, China.
authors.forename: Libo
authors.initials: L
authors.lastname: Jiang
authors.affiliation: Center for Computational Biology, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, 100083, China.
authors.forename: Chaozhong
authors.initials: C
authors.lastname: Shi
authors.affiliation: Center for Computational Biology, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, 100083, China.
authors.forename: Yaru
authors.initials: Y
authors.lastname: Fu
authors.affiliation: Center for Computational Biology, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, 100083, China.
authors.forename: Guomiao
authors.initials: G
authors.lastname: Zhao
authors.affiliation: Center for Computational Biology, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, 100083, China.
authors.forename: Yuejiao
authors.initials: Y
authors.lastname: Huang
authors.affiliation: Center for Statistical Genetics, The Pennsylvania State University, Hershey, PA, 17033, USA.
authors.forename: Kirk
authors.initials: K
authors.lastname: Gosik
authors.affiliation: Center for Computational Biology, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, 100083, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Liang
authors.affiliation: Center for Computational Biology, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, 100083, China.|Center for Statistical Genetics, The Pennsylvania State University, Hershey, PA, 17033, USA.
authors.forename: Rongling
authors.initials: R
authors.lastname: Wu
mesh_terms: D018517:Plant Roots / Q000235:genetics* / Q000254:growth & development*; D018520:Plant Shoots / Q000235:genetics* / Q000254:growth & development*; D032107:Populus / Q000235:genetics* / Q000254:growth & development*; D040641:Quantitative Trait Loci / Q000235:genetics; D036226:Seedlings / Q000235:genetics* / Q000254:growth & development*
keywords: 
  Populus euphratica
  ; functional mapping; growth equation; quantitative trait loci; shoot-root relationship