title: Expression quantitative trait loci infer the regulation of isoflavone accumulation in soybean (Glycine max L. Merr.) seed.
abstract: BACKGROUND
  Mapping expression quantitative trait loci (eQTL) of targeted genes represents a powerful and widely adopted approach to identify putative regulatory variants. Linking regulation differences to specific genes might assist in the identification of networks and interactions. The objective of this study is to identify eQTL underlying expression of four gene families encoding isoflavone synthetic enzymes involved in the phenylpropanoid pathway, which are phenylalanine ammonia-lyase (PAL; EC 4.3.1.5), chalcone synthase (CHS; EC 2.3.1.74), 2-hydroxyisoflavanone synthase (IFS; EC1.14.13.136) and flavanone 3-hydroxylase (F3H; EC 1.14.11.9). A population of 130 recombinant inbred lines (F5:11), derived from a cross between soybean cultivar 'Zhongdou 27' (high isoflavone) and 'Jiunong 20' (low isoflavone), and a total of 194 simple sequence repeat (SSR) markers were used in this study. Overlapped loci of eQTLs and phenotypic QTLs (pQTLs) were analyzed to identify the potential candidate genes underlying the accumulation of isoflavone in soybean seed.
  
  
  RESULTS
  Thirty three eQTLs (thirteen cis-eQTLs and twenty trans-eQTLs) underlying the transcript abundance of the four gene families were identified on fifteen chromosomes. The eQTLs between Satt278-Sat_134, Sat_134-Sct_010 and Satt149-Sat_234 underlie the expression of both IFS and CHS genes. Five eQTL intervals were overlapped with pQTLs. A total of eleven candidate genes within the overlapped eQTL and pQTL were identified.
  
  
  CONCLUSIONS
  These results will be useful for the development of marker-assisted selection to breed soybean cultivars with high or low isoflavone contents and for map-based cloning of new isoflavone related genes.
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
authors.forename: Yingpeng
authors.initials: Y
authors.lastname: Han
authors.forename: Weili
authors.initials: W
authors.lastname: Teng
authors.forename: Xue
authors.initials: X
authors.lastname: Zhao
authors.forename: Yongguang
authors.initials: Y
authors.lastname: Li
authors.forename: Lin
authors.initials: L
authors.lastname: Wu
authors.forename: Dongmei
authors.initials: D
authors.lastname: Li
authors.affiliation: Key Laboratory of Soybean Biology in Chinese Ministry of Education (key Laboratory of Soybean Biology and Breeding/Genetics of Chinese Agriculture Ministry), Northeast Agricultural University, Harbin 150030, China. wenbinli@neau.edu.cn.
authors.forename: Wenbin
authors.initials: W
authors.lastname: Li
mesh_terms: D020869:Gene Expression Profiling; D017343:Genes, Plant / Q000235:genetics; D023281:Genomics; D007529:Isoflavones / Q000378:metabolism*; D018895:Microsatellite Repeats / Q000235:genetics; D010641:Phenotype; D040641:Quantitative Trait Loci / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012639:Seeds / Q000378:metabolism*; D013025:Glycine max / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism*
chemical_list: D007529:Isoflavones; D012333:RNA, Messenger