Species- and genome-wide dissection of the shoot ionome in Brassica napus and its relationship to seedling development

Abstract

Knowing the genetic basis of the plant ionome is essential for understanding the control of nutrient transport and accumulation. The aim of this research was to (i) study mineral nutrient concentrations in a large and diverse set of Brassica napus, (ii) describe the relationships between the shoot ionome and seedling development, and (iii) identify genetic regions associated with variation of the shoot ionome. The plant material under study was a germplasm set consisting of 509 inbred lines that was genotyped by a 6K single nucleotide polymorphism (SNP) array and phenotyped by analyzing the concentrations of eleven mineral nutrients in the shoots of 30 days old seedlings. Among mineral concentrations, positive correlations were found, whereas mineral concentrations were mainly negatively correlated with seedling development traits from earlier studies. In a genome-wide association mapping approach, altogether 29 significantly associated loci were identified across seven traits after correcting for multiple testing. The associations included a locus with effects on the concentrations of Cu, Mn, and Zn on chromosome C3, and a genetic region with multiple associations for Na concentration on chromosome A9. This region was situated within an association hotspot close to SOS1, a key gene for Na tolerance in plants.

QTL meta-analysis of root traits in Brassica napus under contrasting phosphorus supply in two growth systems

“…In B. oleracea the most significant QTL for shoot concentrations of Ca, Mg, Zn and Na occurred on C9 56 . In a B. napus diversity panel, significantly associated SNP markers were observed on C9 and A9 for shoot concentrations of Ca, Mg, Zn and Na 57 , and in the same panel significantly associated GEMs (gene expression markers) for LRD as well as for shoot mineral concentrations were observed on A9 (Thomas et al , 2016, unpublished).…”

The maize shoot ionome: Its interaction partners, predictive power, and genetic determinants

“…The plots in the left column present the logarithm of odds (LOD) versus the position on the genetic map of chromosomes two, two, one, and one, respectively, for a selected set of quantitative trait loci (QTL) with significant main effects across two iron regimes for cadmium (Cd) and molybdenum (Mo) concentration (C-*) and content (A-*) in shoots of the maize IBM population. The plots in the right column are boxplots of the adjusted entry means of the genotypes carrying the B73 or Mo17 allele at the QTL position across the sufficient and deficient Fe regime [Colour figure can be viewed at wileyonlinelibrary.com] earlier studies with maize (Baxter et al, 2013) but also with Brassica napus (Bus et al, 2014) or with 334 angiosperm species . In contrast to previous studies, we not only assessed the concentration of mineral elements but also the shoot content.…”

“…In contrast to most previous studies examining the inheritance of the ionome of different species in single environments or in multiple environments that differ with respect to multiple environmental factors (e.g. Asaro et al, 2016;Bus et al, 2014;Shakoor et al, 2016), we analysed the inheritance under two different environmental conditions that differed only with respect to one environmental factor, in our case the Fe regime. This allows to separate the genotype*Fe regime interaction from the genotype*environment interaction, where the former is biologically easier to interpret.…”

Genome-wide association study (GWAS) reveals genetic loci of lead (Pb) tolerance during seedling establishment in rapeseed (Brassica napus L.)

“…For further exploring genetic factors responding to Pb stress, Genome-wide association study (GWAS), a powerful tool to detect the genetic architecture of complex traits, has been widely used in rice, maize and grasses [12,[32][33][34][35][36][37][38][39]. GWAS has also been used to study HMs concentration, tolerance to Cd and other abiotic stress related quantitative trait loci (QTLs), but not the molecular mechanism of Pb tolerance in B. napus [23,[40][41][42][43].…”