Table 1.
Characteristics of the maize GPDH genes (ZmGPDHs).
Fig 1.
Diagram of the maize GPDH proteins showing the bi-domain structure.
Predicted signal peptides are shown as colored rectangles. The numbered bar indicates the amino acid.
Fig 2.
Phylogenetic tree of GPDH proteins from maize (purple triangles), rice (green diamonds), soybean (red circles), sorghum (yellow squares) and Arabidopsis (black circles).
The full-length amino acid sequences of the GPDH proteins were used to construct the phylogenetic tree using the MEGA 5.0. The information of these genes can be seen in S1 Table.
Fig 3.
Syntenic analysis of GPDH genes from different plant species.
(A) Syntenic analysis of maize, rice, soybean, sorghum and Arabidopsis GPDH genes. (B) Syntenic analysis of maize, rice and sorghum GPDH genes. The chromosomes are depicted as a circle. The colored curves denote the syntenic regions of the GPDH genes.
Fig 4.
Structural analysis of maize and Arabidopsis GPDH genes.
The phylogenetic tree of GPDH proteins from maize and Arabidopsis are shown on the left and are classified into three groups. The exon-intron organization is shown on the right, with exons and introns represented by pink boxs and gray lines, respectively, and untranslated regions indicated by blue arrow.
Fig 5.
The cartoon representation of the predicted 3-dimensional structural models of ZmGPDH1-6.
The 3D structure was generated by homology modeling at the SWISS-MODEL workspace, and the model of Homo sapiens GPD1 (PDB code: 1XOX) and Escherichia coli GlpD (PDB code: 2R46) were used as templates. The a-helices were colored in shocking pink and the β-sheet was shown by yellow arrow.
Fig 6.
Subcellular localization of ZmGPDH-GFP fusion proteins.
(A) Confocal micrographs showing localization of GFP, ZmGPDH4-GFP and ZmGPDH5-GFP. The merged pictures include the green fluorescence channel (first panels) and the chloroplast autofluorescence channel (second panels). (B) Confocal micrographs showing localization of ZmGPDH1-GFP and ZmGPDH3-GFP in mesophyll protoplasts validated a cytosol marker mkate (red). (C) Confocal micrographs showing localization of ZmGPDH1-GFP and ZmGPDH3-GFP in mesophyll protoplasts validated by a mkate-tagged ER marker PIN5 (red). The merged pictures of B and C include the green fluorescence channel (first panels) and the red fluorescence channel (second panels).
Fig 7.
The differential transcript profiling of ZmGPDH genes in different tissues and developmental stages.
(A) The differential transcript accumulation of ZmGPDH genes in maize tissues. The transcripts of ZmGPDHs in subtending leaf was used as a calibrator. (B) The differential transcripts accumulation of ZmGPDHs in developing seeds at 5, 10, 15, 20, 30 and 40 days after flowering (DAF). The transcripts of ZmGPDHs in developing seeds at 40DAF was used as a calibrator. (C) The physiological phenotype in developing seeds at 5, 10, 15, 20, 30 and 40 days after flowering (DAF). The asterisks indicate that the corresponding genes are significantly up or down-regulated in different tissues, as determined by the Student’s t-test (*P < 0.05, ** P < 0.01).
Fig 8.
The transcript profiling of ZmGPDHs in response to NaCl (A), NaHCO3 (B), PEG (C), 4°C (D) treatments in leaves of maize seedlings. The transcripts of ZmGPDHs in control environment was used as a calibrator. The asterisks indicate that the corresponding genes were significantly up or down-regulated in response to different treatments, as determined by the Student’s t-test (*P < 0.05, ** P < 0.01).