title: Transcriptomic evidence for the control of soybean root isoflavonoid content by regulation of overlapping phenylpropanoid pathways.
abstract: Isoflavonoids are a class of specialized metabolites found predominantly in legumes. They play a role in signaling for symbiosis with nitrogen-fixing bacteria and inhibiting pathogen infection.
  
  
  
  A transcriptomic approach using soybean cultivars with high (Conrad and AC Colombe) and low (AC Glengarry and Pagoda) root isoflavonoid content was used to find elements that underlie this variation. Two genes, encoding the flavonoid-metabolizing enzymes, flavonoid 3'-hydroxylase (GmF3'H) and dihydroflavonol 4-reductase (GmDFR), had lower expression levels in high isoflavonoid cultivars. These enzymes compete with isoflavonoid biosynthetic enzymes for the important branch-point substrate naringenin and its derivatives. Differentially expressed genes, between the two sets of cultivars, encode transcription factors, transporters and enzymatic families of interest, such as oxidoreductases, hydrolases and transferases. In addition, genes annotated with stress and disease response were upregulated in high isoflavonoid cultivars.
  
  
  
  Coordinated regulation of genes involved in flavonoid metabolism could redirect flux into the isoflavonoid branch of the phenylpropanoid pathway, by reducing competition for the flavanone substrate. These candidate genes could help identify mechanisms to overcome the endogenous bottleneck to isoflavonoid production, facilitate biosynthesis in heterologous systems, and enhance crop resistance against pathogenic infections.
authors.affiliation: Department of Biology, University of Western Ontario, London, ON, Canada.|London Research and Development Centre, Agriculture and Agri-Food Canada, 1391 Sandford Street, London, ON, N5V 4T3, Canada.
authors.forename: Mehran
authors.initials: M
authors.lastname: Dastmalchi
authors.affiliation: London Research and Development Centre, Agriculture and Agri-Food Canada, 1391 Sandford Street, London, ON, N5V 4T3, Canada.
authors.forename: Patrick
authors.initials: P
authors.lastname: Chapman
authors.affiliation: London Research and Development Centre, Agriculture and Agri-Food Canada, 1391 Sandford Street, London, ON, N5V 4T3, Canada.
authors.forename: Jaeju
authors.initials: J
authors.lastname: Yu
authors.affiliation: Department of Biology, University of Western Ontario, London, ON, Canada.|London Research and Development Centre, Agriculture and Agri-Food Canada, 1391 Sandford Street, London, ON, N5V 4T3, Canada.
authors.forename: Ryan S
authors.initials: RS
authors.lastname: Austin
authors.affiliation: Department of Biology, University of Western Ontario, London, ON, Canada. sangeeta.dhaubhadel@canada.ca.|London Research and Development Centre, Agriculture and Agri-Food Canada, 1391 Sandford Street, London, ON, N5V 4T3, Canada. sangeeta.dhaubhadel@canada.ca.
authors.forename: Sangeeta
authors.identifier: 0000-0003-2582-5503
authors.initials: S
authors.lastname: Dhaubhadel
mesh_terms: D020869:Gene Expression Profiling; D007529:Isoflavones / Q000378:metabolism*; D058977:Molecular Sequence Annotation; D018517:Plant Roots / Q000378:metabolism*; D013025:Glycine max / Q000235:genetics* / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: D007529:Isoflavones
keywords: Isoflavonoid; Phenylpropanoid; RNA sequencing; Root; Secondary metabolism; Soybean; Transcriptome