title: Differential detection of genetic Loci underlying stem and root lignin content in Populus.
abstract: In this study, we established a comprehensive genetic map with a large number of progeny from a three-generation hybrid Populus intercross, and phenotyped the lignin content, S/G ratio and 28 cell wall subcomponents both in stems and roots for the mapping individuals. Phenotypic analysis revealed that lignin content and syringyl-to-guaiacyl (S/G) ratio using pyrolysis molecular beam mass spectroscopy (pyMBMS) varied among mapping individuals. Phenotypic analysis revealed that stem lignin content is significantly higher than that in root and the quantified traits can be classified into four distinct groups, with strong correlations observed among components within organs. Altogether, 179 coordinating QTLs were detected, and they were co-localized into 49 genetic loci, 27 of which appear to be pleiotropic. Many of the detected genetic loci were detected differentially in stem and root. This is the first report of separate genetic loci controlling cell wall phenotypes above and below ground. These results suggest that it may be possible to modify lignin content and composition via breed and/or engineer as a means of simultaneously improving Populus for cellulosic ethanol production and carbon sequestration.
authors.affiliation: Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America.
authors.forename: Tongming
authors.initials: T
authors.lastname: Yin
authors.forename: Xinye
authors.initials: X
authors.lastname: Zhang
authors.forename: Lee
authors.initials: L
authors.lastname: Gunter
authors.forename: Ranjan
authors.initials: R
authors.lastname: Priya
authors.forename: Robert
authors.initials: R
authors.lastname: Sykes
authors.forename: Mark
authors.initials: M
authors.lastname: Davis
authors.forename: Stan D
authors.initials: SD
authors.lastname: Wullschleger
authors.forename: Gerald A
authors.initials: GA
authors.lastname: Tuskan
mesh_terms: D000465:Algorithms; D000704:Analysis of Variance; D002874:Chromosome Mapping; D032461:Chromosomes, Plant / Q000235:genetics; D003433:Crosses, Genetic; D017343:Genes, Plant / Q000235:genetics; D056426:Genetic Loci / Q000235:genetics*; D005838:Genotype; D008031:Lignin / Q000378:metabolism*; D008957:Models, Genetic; D010641:Phenotype; D018517:Plant Roots / Q000235:genetics* / Q000378:metabolism; D018547:Plant Stems / Q000235:genetics* / Q000378:metabolism; D032107:Populus / Q000235:genetics* / Q000378:metabolism; D025341:Principal Component Analysis; D040641:Quantitative Trait Loci / Q000235:genetics
chemical_list: C434470:guaiacyl monolignol; C434469:syringyl monolignol; D008031:Lignin