Table 1

Primer sequences and their uses"

Fig. 1

Gene structures of GmbHLH119 and GmbHLH120 in soybean Green regions indicate untranslated regions, yellow regions indicate exons, and thin black lines indicate introns."

Fig. 2

Expression patterns of GmbHLH119 and GmbHLH120 in different tissues in soybean"

Fig. 3

Analysis of cis-acting elements in the promoters of GmbHLH119 and GmbHLH120 in soybean"

Fig. 4

Phylogenetic tree of bHLH proteins from Glycine max, Arabidopsis thaliana, Oryza sativa, Triticum aestivum, Medicago truncatula, Lotus japonicus, and Phaseolus vulgaris Numbers at the branch nodes indicate bootstrap values, and branch lengths represent evolutionary distances. The scale bar of 0.20 indicates 0.2 substitutions per site. Gm: Glycine max; At: Arabidopsis thaliana; Os: Oryza sativa; Ta: Triticum aestivum; Mt: Medicago truncatula; Lj: Lotus japonicus; Pv: Phaseolus vulgaris."

Fig. 5

Protein sequence alignment of GmbHLH119 and GmbHLH120 The red underlined region indicates the HLH domain."

Table 2

Basic characteristics of GmbHLH119 and GmbHLH120 proteins in soybean"

Table 3

Major secondary structure types of GmbHLH119 and GmbHLH120 proteins"

Fig. 6

Predicted secondary and tertiary structures of GmbHLH119 and GmbHLH120 in soybean A: secondary structures of GmbHLH119 and GmbHLH120; aa: amino acid; the blue area represents the α-helix structure; the purple area represents the extended strand structure; the green area represents the β-turn structure; the yellow area represents the random coil structure. B: tertiary structures of GmbHLH119 and GmbHLH120; pLDDT: confidence score of each residue."

Fig. 7

Construction of subcellular localization vectors A: subcellular localization vector structure; B: PCR identification of pTF101-GmbHLH119-GFP and pTF101-GmbHLH120-GFP vector in Escherichia coli colonies; M is 2 kb ladder DNA marker."

Fig. 8

Subcellular localization of GmbHLH119 and GmbHLH120 proteins GFP indicates the GFP fluorescence channel, Chlorophyll indicates chlorophyll autofluorescence, DAPI indicates DAPI-stained nuclei, Bright indicates bright-field images, and Merged indicates merged images; scale bar = 25 μm."

Fig. 9

Expression of GmNiR in different soybean tissues under different nitrogen treatments LN: low nitrogen (0.5 mmol L-1 N); NN: normal nitrogen (5 mmol L-1 N); HN: high nitrogen (15 mmol L-1 N). Statistical analysis was performed using Student’s t-test; *, ** mean significant difference at P < 0.05 and P < 0.01, respectively."

Fig. 10

Expression of GmbHLH119 and GmbHLH120 in different soybean tissues under different nitrogen treatments A: expression of GmbHLH119 in different tissues of soybean under different nitrogen treatments; B: expression of GmbHLH120 in different tissues of soybean under different nitrogen treatments. LN: low nitrogen (0.5 mmol L-1 N); NN: normal nitrogen (5 mmol L-1 N); HN: high nitrogen (15 mmol L-1 N). Statistical analysis was performed using Student’s t-test; ns: no significant difference; *, **, *** mean significant difference at P < 0.05, P < 0.01 and P < 0.001, respectively."

Fig. 11

Expression of GmPLDZ in different soybean tissues under different phosphorus treatments LP: low phosphorus (5 μmol L-1 KH2PO4); NP: normal phosphorus (500 μmol L-1 KH2PO4). Statistical analysis was performed using Student’s t-test; **, **** mean significant difference at P < 0.01 and P < 0.0001, respectively."

Fig. 12

Expression of GmbHLH119 and GmbHLH120 in different soybean tissues under different phosphorus treatments A: expression of GmbHLH119 in different tissues of soybean under different phosphorus treatments; B: expression of GmbHLH120 in different tissues of soybean under different phosphorus treatments. LP: low phosphorus (5 μmol L-1 KH2PO4); NP: normal phosphorus (500 μmol L-1 KH2PO4). Statistical analysis was performed using Student’s t-test; ns: no significant difference; *, **, ***, **** mean significant difference at P < 0.05, P < 0.01, P < 0.001, and P < 0.0001, respectively."