Functional complementation.

<p>Relative primary root lengths are shown for NIL[Sha] plants and for transgenic NIL[Sha] plants expressing either the <i>FRD3^Bay</i> or the <i>FRD3^Sha</i> allele. Relative primary root length is the primary root length of plants grown at 150 µM Zn as a percentage of the primary root length of plants grown at 1 µM Zn. Error bars represent confidence intervals calculated after logarithmic transformation of data <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1003120#pgen.1003120-Hedges1" target="_blank">[41]</a> (P<0.05; n = 7 to 21). Similar increased relative root lengths were observed in 2 additional independent NIL[Sha] lines complemented with <i>FRD3^Bay</i> (data not shown).</p

Fe and Zn homeostasis in NILs and parental lines.

<p>Fe (A) and Zn (C) concentrations in xylem exudates. Plants were grown in a growth chamber for 6 weeks and xylem exudates were collected during 30 min after removing aerial parts of the plant at the hypocotyl. Fe (B) and Zn (D) shoot content. Plants were grown on agar plates under control (contr.), 200 µM Zn (+ Zn), and 200 µM Fe plus 200 µM Zn (+ Zn Fe) conditions for 10 days. Percentages given above bars in (B) refer to the difference in shoot Fe content in ‘+ Zn’ conditions as a percentage of the control value. Measurements were performed on sets of 5 to 20 plants. Values are the means ± S.D.M. Different letters above bars refer to significantly different values (P<0.05), according to non-parametric tests for (A), (B) and (D) and Tukey tests for (C) where n = 3–8.</p

QTL and fine-mapping of the ZnT2 locus.

<p>(A) Root phenotype of 10-day-old Bay-0 and Sha plants grown on agar plates containing 1 µM or 150 µM Zn. Bay-0 is more Zn-tolerant than Sha. Scale bar, 1 cm. (B) QTL map for the response of the primary root length to Zn (relative primary root length of plants grown at 150 µM and 1 µM Zn), evaluated in a sub-set of 165 RILs from the Bay-0×Sha RIL population. The map was obtained by composite interval mapping and a LOD threshold of 2.5 obtained from permutation. (C) Fine mapping of the ZnT2 QTL. ZnT2, initially mapped between markers NGA172 and MSAT3.19, was localized between MSAT302503 and MSAT2630717 and narrowed down to between CAPS2560983 and CAPS2587730 by recombinant screening. This 23 kb-long region encompasses 7 full-length genes including <i>FRD3</i>. Zn tolerance phenotypes of recombinant plants with informative genotypes are given. Black and grey bars represent Bay and Sha genomes, respectively.</p

Natural variation in the <i>FRD3</i> sequence, FRD3 transport activity, and <i>FRD3</i> transcript accumulation.

<p>(A) Gene organization and allelic variations identified at the <i>FRD3</i> locus in Col-0 (reference sequence), Bay-0 and Sha. In non-coding regions, only insertions and deletions are shown. In the coding region, synonymous SNPs are not indicated. (B) ¹³[C]-citrate efflux activity resulting from the expression of FRD3^Bay (Bay), FRD3^Col (Col) and FRD3^Sha (Sha) proteins or the co-expression of FRD3^Sha and FRD3^Col (Col+Sha) in <i>Xenopus</i> oocytes. In control oocytes (Ø), no RNA was injected. Data are the means ± S.D.M. for n = 3 sets of 14 oocytes. (C) <i>FRD3</i> transcript accumulation under Fe deficiency (Fe 0), control conditions (Zn 1) and excess Zn (Zn 200) in parental and NIL lines. <i>FRD3</i> transcript levels are shown relative to the transcript level of ACT2/ACT8. Values represent the means ± S.D.M. for n = 3 biologically independent experiments. Different letters above bars indicate significantly different values within a treatment set (P<0.05) according to a non-parametric test for Fe0, and Zn200 and a Tukey test for Zn1. The table indicates <i>FRD3</i> transcript levels for the Fe0 and Zn200 conditions relative to those for the control Zn1 condition.</p

Additional file 1: of Association of environmental markers with childhood type 1 diabetes mellitus revealed by a long questionnaire on early life exposures and lifestyle in a case–control study

The questionnaire used in the current study. (PDF 620 kb