Fig. 3: BdTOM1 confers resilience to Fe deficiency in Brachypodium distachyon.

a Expression of BdTOM1 and BdTOM3 in Bd21 and Bd21-3 accessions grown in artificial phenolic resin blocks containing 2.5 mg Fe L⁻¹ of non-chelated iron [Fe₂(SO₄)₃] under HC for 3 weeks. The first fully expanded leaves and root tissues were collected at the indicated time points. *P < 0.05; **P < 0.001 (two-tailed Student’s t test, Bd21 vs Bd21-3; n = 3, biological replicates). b BdTOM1 and BdTOM3 expression in seedlings grown hydroponically with 2.5 mg Fe L⁻¹ chelated iron (Fe-EDTA) or without iron (Fe-free) under NC or HC for 1 week. *P < 0.05; **P < 0.001 (two-tailed Student’s t test, Bd21 vs Bd21-3; n = 3, biological replicates). c Bd21, Bdtom1, and Bdtom3 plants grown in artificial phenolic resin blocks containing 2.5 mg Fe L⁻¹ non-chelated iron (NC) alone or with 30 µM proline-2′-deoxymugineic acid (NC + PDMA) under NC for 4 weeks. Aboveground fresh weight (d) and leaf Fe content (e) of Bd21, Bdtom1, and Bdtom3 plants grown in artificial phenolic resin blocks containing 2.5 mg Fe L⁻¹ non-chelated iron alone or with 30 µM PDMA under NC for 4 weeks. Different lowercase letters indicate significant differences between groups [one-way ANOVA; d: F (9, 29) = 16.01, P = 5.11 × 10⁻⁹, n = 3–4; e: F (9, 30) = 15.68, P = 4.41 × 10⁻⁹, n = 4; Tukey’s HSD test, two-sided, adjusted for multiple comparisons]. f Expression of iron deficiency–marker BdIRO2.1 and heat shock protein BdHSP70-2 in the roots of Bd21, Bdtom1, and Bdtom3 seedlings grown in artificial phenolic resin blocks containing 2.5 mg Fe L⁻¹ non-chelated iron under NC for 4 weeks. *P < 0.05, **P < 0.001 (two-tailed Student’s t tests, Bd21 vs. each mutant line; n = 4, biological replicates). Data are means ± SEM. Exact P values for significant differences are labeled on the graphs. Source data are provided as a Source Data file.