Identification of metabolic QTLs and candidate genes for glucosinolate synthesis in Brassica oleracea leaves, seeds and flower buds

PLoS One. 2014 Mar 10;9(3):e91428. doi: 10.1371/journal.pone.0091428. eCollection 2014.

Abstract

Glucosinolates are major secondary metabolites found in the Brassicaceae family. These compounds play an essential role in plant defense against biotic and abiotic stresses, but more interestingly they have beneficial effects on human health. We performed a genetic analysis in order to identify the genome regions regulating glucosinolates biosynthesis in a DH mapping population of Brassica oleracea. In order to obtain a general overview of regulation in the whole plant, analyses were performed in the three major organs where glucosinolates are synthesized (leaves, seeds and flower buds). Eighty two significant QTLs were detected, which explained a broad range of variability in terms of individual and total glucosinolate (GSL) content. A meta-analysis rendered eighteen consensus QTLs. Thirteen of them regulated more than one glucosinolate and its content. In spite of the considerable variability of glucosinolate content and profiles across the organ, some of these consensus QTLs were identified in more than one tissue. Consensus QTLs control the GSL content by interacting epistatically in complex networks. Based on in silico analysis within the B. oleracea genome along with synteny with Arabidopsis, we propose seven major candidate loci that regulate GSL biosynthesis in the Brassicaceae family. Three of these loci control the content of aliphatic GSL and four of them control the content of indolic glucosinolates. GSL-ALK plays a central role in determining aliphatic GSL variation directly and by interacting epistatically with other loci, thus suggesting its regulatory effect.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Analysis of Variance
  • Brassica / genetics*
  • Brassica / metabolism*
  • Chromosome Mapping
  • Epistasis, Genetic
  • Flowers / genetics*
  • Flowers / metabolism
  • Genes, Plant
  • Genetic Association Studies*
  • Glucosinolates / biosynthesis*
  • Glucosinolates / chemistry
  • Haploidy
  • Humans
  • Phenotype
  • Plant Leaves / genetics*
  • Plant Leaves / metabolism
  • Quantitative Trait Loci / genetics*
  • Seeds / genetics*
  • Seeds / metabolism

Substances

  • Glucosinolates

Grants and funding

This work was supported by the National Plan for Research and Development (AGL-2009-09922). Tamara Sotelo acknowledges a pre-doctoral research grant (F.P.I) from the Ministry of Economy and Competitiveness. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.