A strong effect of growth medium and organ type on the identification of QTLs for phytate and mineral concentrations in three Arabidopsis thaliana RIL populations

Abstract

The regulation of mineral accumulation in plants is genetically complex, with several genetic loci involved in the control of one mineral and loci affecting the accumulation of different minerals. To investigate the role of growth medium and organ type on the genetics of mineral accumulation, two existing (LerxKond, LerxAn-1) and one new (LerxEri-1) Arabidopsis thaliana Recombinant Inbred Line populations were raised on soil and hydroponics as substrates. Seeds, roots, and/or rosettes were sampled for the determination of their Ca, Fe, K, Mg, Mn, P or Zn concentrations. For seeds only, the concentration of phytate (IP6), a strong chelator of seed minerals, was determined. Correlations between minerals/IP6, populations, growth conditions, and organs were determined and mineral/IP6 concentration data were used to identify quantitative trait loci (QTLs) for these traits. A striking difference was found between QTLs identified for soil-grown versus hydroponics-grown populations and between QTLs identified for different plant organs. Three common QTLs were identified for several populations, growth conditions, and organs, one of which corresponded to the ERECTA locus, variation of which has a strong effect on plant morphology.

Genetic analysis of the effect of zinc deficiency on Arabidopsis growth and mineral concentrations

“…In the same region, QTLs were previously found for Fe and Mg concentrations in seeds (Waters and Grusak 2008). The confidence interval of the Zn concentration locus overlaps with those for seed Zn concentration QTLs previously found in the Ler × Cvi and Ler × An-1 populations (Ghandilyan et al 2009b;Vreugdenhil et al 2004), but Trait explanations are provided in Table 1. Per QTL is its chromosome number (Chr.…”

“…allele) (Vreugdenhil et al 2004;Waters and Grusak 2008). The reason for this apparent discrepancy could be the difference in growing conditions (nutrient amended Zn deficient calcareous soil vs. peat-based potting soil) as well as the fact that regulation of mineral homeostasis depends on organ type as well (Ghandilyan et al 2009b). We found a negative correlation between shoot Zn concentrations and shoot biomass on Zn deficient and sufficient conditions.…”

“…The A. thaliana Ler × Cvi Recombinant Inbred Line (RIL) immortal mapping population (Alonso-Blanco et al 1998), derived from a cross between the Landsberg erecta (Ler) lab strain and the Cape Verde Islands (Cvi) accession, has been used extensively to study the genetic basis of multiple traits in Arabidopsis (recently reviewed by (Alonso-Blanco et al 2009)) including mineral content in seeds (Vreugdenhil et al 2004;Waters and Grusak 2008). QTL analyses of mineral concentrations in seeds, rosettes and roots were conducted in Arabidopsis Ler × Kond, Ler × An-1 and Ler × Eri populations grown under various conditions (Ghandilyan et al 2009b).…”

The Use of Hydroponic Growth Systems to Study the Root and Shoot Ionome of Arabidopsis thaliana

“…The commonly utilized genetically divergent A. thaliana populations are natural accessions, recombinant inbred lines (RIL), and mutant lines. Such populations were used in several high-throughput studies, which resulted in the identification of many quantitative trait loci (QTLs) controlling the A. thaliana ionome (Buescher et al, 2010;Ghandilyan et al, 2009;Lahner et al, 2003;Prinzenberg et al, 2010). Due to the high-throughput nature of these studies, the A. thaliana plants were grown in soil in many cases, and the elemental composition was determined in shoots but not in roots.…”

“…RIL populations of A. thaliana grown in hydroponic systems were utilized to identify QTLs that correlate the mineral composition of roots, leaves, and seeds with phytate content and growth-related traits (Ghandilyan et al, 2009;Prinzenberg et al, 2010). The parental A. thaliana accessions utilized in these studies were Ler-3, Kas-2, Kon, An-1, and Eri-1.…”