Iron uptake and sulfate assimilation. One of two maps the review motivates but does not draw. That is an odd gap, because mineral nutrition is where the direct Arabidopsis near-null-field evidence is strongest: three separate studies report effects on root mineral nutrition, iron uptake efficiency and Fe-S interplay. The map makes the loop visible. Sulfate assimilation supplies the sulfide that every cluster on QBM-04 is built from, and sulfite reductase is itself a ferredoxin-dependent siroheme-[4Fe-4S] enzyme drawing on plastid reducing power from QBM-02 — so iron and sulfur status are not two inputs but one feedback system, which is exactly why Vigani et al. found the effect most pronounced under combined Fe and S deficiency. Note the tier pattern: uptake and assimilation are T2 on real evidence, but they are classed as structural context because no quantum route is proposed for them. A demonstrated effect with no mechanism is recorded here as precisely that. Derived from: Motivated by section 6 and the Islam 2020 / Vigani 2021 / Narayana 2018 evidence in Porterfield & Barker, "Plant Responses to Near-Null Magnetic Fields" — no corresponding figure exists in the manuscript structural_context CHEBI:29033 CHEBI:29034 CHEBI:16189 The geomagnetic field contributes to efficient iron uptake in Arabidopsis; reducing it to near-null affects root metal reductase activity. Geomagnetic-field-dependent modulation of iron-sulfur interplay in Arabidopsis, most pronounced under combined Fe and S deficiency. Reduction of the geomagnetic field to near-null affects Arabidopsis root mineral nutrition. Note carefully what the cited work does and does not show. Islam 2020 and Vigani 2021 measured iron uptake and Fe-S interplay under altered field conditions — nutritional physiology. Neither measured cluster assembly. This entity is T2 because the field effect is demonstrated for the process it names; the assembly entities above remain T3 because that evidence does not reach them. structural_context AT1G01580 AT4G19690 AT2G28160 AT3G56970 AT3G56980 AT1G23020 GO:0005886 The geomagnetic field contributes to efficient iron uptake in Arabidopsis; near-null conditions affect root metal reductase activity. Near-null magnetic field conditions affect Arabidopsis root mineral nutrition. Carries demonstrated near-null-field evidence and NO proposed quantum route, and is classed structural_context to say so. Islam et al. measured reduced root metal reductase activity under field reduction — a real, reproducible effect with no mechanism attached. FRO2 is a flavocytochrome with FAD and two hemes, so a spin route could be argued; the review does not argue it, and no measurement supports it, so it is not claimed here. iron_sulfur_4Fe4S 57Fe 33S AT4G08620 AT1G78000 AT5G10180 AT3G22890 AT4G04610 AT1G62180 AT4G21990 AT5G04590 2.7.7.4 1.8.4.9 1.8.7.1 Field conditions modulate Fe-S interplay in Arabidopsis, most strongly under combined iron and sulfur deficiency. Sulfite reductase carries a siroheme-[4Fe-4S] cofactor and is ferredoxin- dependent, so this pathway both consumes plastid reducing power and contains an Fe/S centre. It also supplies the sulfide that every cluster on QBM-04 is built from — a genuine feedback loop rather than a linear dependency. structural_context AT5G01600 AT2G40300 AT1G56430 AT2G23150 AT5G67330 AT3G12750 structural_context AT1G55920 AT4G14880 2.3.1.30 2.5.1.47 structural_context AT5G65720 2.8.1.7 iron_sulfur_2Fe2S 57Fe 33S AT4G22220 Holds a transient, solvent-exposed [2Fe-2S] cluster whose assembly involves iron redox chemistry and sulfide transfer. A nascent cluster on a scaffold is more exposed and shorter-lived than a mature one buried in a protein, which makes it a more credible point of perturbation than the finished product. Entirely untested. No experiment has measured scaffold occupancy or transfer rate under any magnetic field condition. iron_sulfur_4Fe4S 57Fe 33S AT1G08490 AT4G26500 Builds every cluster in the chloroplast, including PSI's FX/FA/FB and ferredoxin's [2Fe-2S]. It is the single upstream dependency of QBM-02's strongest nodes. iron_sulfur_4Fe4S iron_sulfur_2Fe2S 57Fe 33S AT4G35830 AT5G66760 AT5G13430 AT4G03280 AT1G10960 AT2G20860 AT2G21790 Collected here so the map can show, in one edge, that a single assembly defect reaches respiration, photosynthesis, the TCA cycle, nitrogen and sulfur assimilation and DNA replication simultaneously. That breadth is the review's argument for why Fe/S biology deserves attention ahead of cryptochrome. iron_sulfur_2Fe2S 57Fe 33S AT1G10960 AT1G60950 GO:0009570 Geomagnetic field conditions modulate iron-sulfur interplay in Arabidopsis, particularly under combined iron and sulfur deficiency. The distribution hub of plastid reducing power. A perturbation here reaches carbon fixation, nitrogen and sulfur assimilation and redox regulation at once, which is why the review nominates ferredoxin biogenesis specifically. direct_influence direct_influence direct_influence direct_influence cofactor_insertion direct_influence cofactor_insertion cofactor_insertion direct_influence cofactor_insertion cofactor_insertion redox_feedback redox_feedback