Fig. 7: GmNIGT1a&1b regulate Fe homeostasis in nodules.

a–d Seedling and nodule growth in knockdown (nigt1ab-RNAi), knockout (nigt1ab-cr) and overexpression (GmNIGT1a-OE) lines. a Whole-plant growth. Scale bars, 2 cm. b Plant biomass. c Nodule weight. d Nodule number. 4-day-old seedlings were inoculated with rhizobia and grown in a low-N nutrient solution for 21 d. WT1, the wild-type control for nigt1ab-RNAi and nigt1ab-cr. WT2, the wild-type control for GmNIGT1a-OE lines. e–f Gene expression of GmNRAMP2a (e) and 2b (f) in nodules of nigt1ab-RNAi, nigt1ab-cr and GmNIGT1a-OE lines. Nodules at 21 dpi were treated without (CK) or with high-N (H–N) solution for 1 d. Relative expression levels were determined by real-time RT-PCR. EF-1α was used as an internal standard. g–m Ureide export rate (g, h), nodule Fe intensity (i, j), Fe bodies in uninfected cell (k, l), lytic vacuoles in infected cell (m) of nigt1ab-RNAi, nigt1ab-cr and GmNIGT1a-OE lines. Nodules at 21 dpi were treated without (CK) or with high-N (H–N) solution for 2 d. Nodule samples were sectioned and stained with Perls solution, followed by DAB intensification. Yellow arrows and blue asterisks in (k) indicate Fe bodies and lytic vacuoles respectively. Scale bars = 1 mm (i), 50 μm (k). The boxes in (b–h, j, l, m) indicate the first and third quartiles, and the whiskers indicate the minimum and maximum values. The lines within the boxes indicate the median values. The number of biologically independent replicates (n) is indicated at the bottom of each box in the figures. The P values show significant differences compared with WT. All P values were calculated using two-sided t-test. The phenotypic statistics for the overexpression and RNAi materials were based on two independent lines, and for each treatment, at least three plants per line were evaluated. Source data are provided as a Source Data file.