title: Identification of novel QTL governing root architectural traits in an interspecific soybean population.
abstract: Cultivated soybean (Glycine max L.) cv. Dunbar (PI 552538) and wild G. soja (PI 326582A) exhibited significant differences in root architecture and root-related traits. In this study, phenotypic variability for root traits among 251 BC2F5 backcross inbred lines (BILs) developed from the cross Dunbar/PI 326582A were identified. The root systems of the parents and BILs were evaluated in controlled environmental conditions using a cone system at seedling stage. The G. max parent Dunbar contributed phenotypically favorable alleles at a major quantitative trait locus on chromosome 8 (Satt315-I locus) that governed root traits (tap root length and lateral root number) and shoot length. This QTL accounted for >10% of the phenotypic variation of both tap root and shoot length. This QTL region was found to control various shoot- and root-related traits across soybean genetic backgrounds. Within the confidence interval of this region, eleven transcription factors (TFs) were identified. Based on RNA sequencing and Affymetrix expression data, key TFs including MYB, AP2-EREBP and bZIP TFs were identified in this QTL interval with high expression in roots and nodules. The backcross inbred lines with different parental allelic combination showed different expression pattern for six transcription factors selected based on their expression pattern in root tissues. It appears that the marker interval Satt315-I locus on chromosome 8 contain an essential QTL contributing to early root and shoot growth in soybean.
authors.affiliation: Division of Plant Sciences, University of Missouri, Columbia, Missouri, United States of America.
authors.forename: Lakshmi P
authors.initials: LP
authors.lastname: Manavalan
authors.affiliation: Division of Plant Sciences, University of Missouri, Columbia, Missouri, United States of America.
authors.forename: Silvas J
authors.initials: SJ
authors.lastname: Prince
authors.affiliation: Division of Plant Sciences, University of Missouri, Columbia, Missouri, United States of America.
authors.forename: Theresa A
authors.initials: TA
authors.lastname: Musket
authors.affiliation: Department of Agronomy and Horticulture, University of Nebraska, Lincoln, Nebraska, United States of America.
authors.forename: Julian
authors.initials: J
authors.lastname: Chaky
authors.affiliation: Division of Plant Sciences, University of Missouri, Columbia, Missouri, United States of America.
authors.forename: Rupesh
authors.initials: R
authors.lastname: Deshmukh
authors.affiliation: Division of Plant Sciences, University of Missouri, Columbia, Missouri, United States of America.
authors.forename: Tri D
authors.initials: TD
authors.lastname: Vuong
authors.affiliation: Division of Plant Sciences, University of Missouri, Columbia, Missouri, United States of America.
authors.forename: Li
authors.initials: L
authors.lastname: Song
authors.affiliation: Soybean Genomics and Improvement Lab, USDA-ARS, Beltsville, Maryland, United States of America.
authors.forename: Perry B
authors.initials: PB
authors.lastname: Cregan
authors.affiliation: Department of Plant Pathology, Kansas State University, Manhattan, Kansas, United States of America.
authors.forename: James C
authors.initials: JC
authors.lastname: Nelson
authors.affiliation: Division of Plant Sciences, University of Missouri, Columbia, Missouri, United States of America.
authors.forename: J Grover
authors.initials: JG
authors.lastname: Shannon
authors.affiliation: Department of Agronomy and Horticulture, University of Nebraska, Lincoln, Nebraska, United States of America.
authors.forename: James E
authors.initials: JE
authors.lastname: Specht
authors.affiliation: Division of Plant Sciences, University of Missouri, Columbia, Missouri, United States of America.
authors.forename: Henry T
authors.initials: HT
authors.lastname: Nguyen
mesh_terms: D004843:Epistasis, Genetic; D056726:Genetic Association Studies; D010641:Phenotype; D018517:Plant Roots / Q000033:anatomy & histology / Q000235:genetics* / Q000254:growth & development; D018520:Plant Shoots; D040641:Quantitative Trait Loci; D013025:Glycine max / Q000033:anatomy & histology / Q000235:genetics* / Q000254:growth & development