A Genome-Wide Approach to Understand Nutriomics in Brassica Species

Genomic study and nutrition research have been developed in parallel for a long time. Plant nutriomics is a new frontier in plant biology, involving genomic, transcriptomic, proteomic and metabolomics in a network. Brassica species constitutes one of the world’s most diverse and economically important plant groups with variations of functional compounds such as glucosinolates, β-carotene, lutein, phenolic acids, flavonoids, etc. However, it is still less known about the genetic basis and regulation of their biosynthesis in Brassica species. Thus, we combined a genome wide comparative study, QTL mapping and large scale microarray analysis to discover their metabolic pathways and regulatory mechanisms of related genes. QTL analysis for glucosinolate accumulation in B. rapa seeds was carried out by using a CRF₃ population, derived from a cross between “Chiifu” and rapid cycling type “RCBr” which showed significant difference in glucosinolate content. Twenty four loci controlling each ten and total glucosinolate compound were identified, with one major locus in chromosome A08. Through synteny genomic comparison to A. thaliana, candidate genes and single nucleotide polymorphisms (SNPs) between parental lines were identified from whole genome re-sequenced data by NGS. In addition, 57 full length CDs were identified for carotenoids from Brassica. These genes were also identified in in-home developed 50K microarray dataset for Chiifu and RCBr, and their levels of differential expressions were checked. Moreover, numerous collected Brassica accessions and germplasms supported by Korea Brassica Genome Resource Bank were also used for important functional compound analysis which paves the way for the gene association study and evolutionary study in future.