script levels in seedlings samples after salt and drought treatment with 24 and

Script levels in seedlings samples after salt and

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script levels in seedlings samples after salt and drought treatment with 24 and 3 h, respectively. Control (CK) seedlings were grown with normal irrigation. Asterisk indicates a significant difference from the control ( p <0.05). Error bars indicate standard error of independent biological replicates Plant Mol Biol Rep
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consistent with our research on the expression profiles of ZmDof13 ( PBF ) gene. From Fig. 5 , we also found that ZmDof46 and ZmDof33 have high expression level in the germinating seed, implying that these genes may be in- volved in first 24 h germinating seed development in maize. Members in the same gene group of the phylogenetic tree usually originate from duplication of an ancestral gene and have a very similar sequence composition. Here, we also investigated the expression profiles of duplicated Dof genes in maize and found that most of duplicates exhibited diver- gent expression profiles (Fig. 5 ). It suggests that due to a relaxation of functional constraints and adaptation to new functions, duplicated genes usually exhibit divergence in expression profiles, which maybe confer an evolutionary advantage for organisms living in the changing environment (Farré and Albà 2010 ). Some members of Dof gene family were demonstrated to be regulated by salt and drought in Triticum aestivum (Shaw et al. 2009 ). However, few Dof genes in response to salt and drought treatments were re- ported in maize. For this purpose, we investigated the ex- pression patterns of maize Dof genes under salt and drought treatments. Expression profiles of eight ZmDof genes re- sponses to salt and drought treatments were identified by qRT-PCR analyses. As a result, six of eight ZmDof genes detected were upregulated during salt treatment of seedlings (Fig. 6 ). Among them, ZmDof22 , ZmDof16 , and ZmDof36 were significantly upregulated at 50 times, 25 times, and 40 times higher than the control ones, respectively. We also found that ZmDof06 was upregulated under drought treat- ment, implying that this gene is more likely to play critical roles in regulating drought response in maize seedlings. Conclusions Transcriptional regulation plays an important role in the pro- cess of gene expression, and this process is determined by the number, position and interaction between different cis -ele- ments and transcription factors. Dof gene family is a plant- specific transcription factor. Genome-wide identification, phylogenetic analyses, chromosomal location, gene structure and motif analysis, cis -elements, selective pressures, and ex- pression profiling were performed to analyze this gene family in maize. As a result, 46 Dof genes were identified in maize. Gene structure and motif analysis revealed that the Dof motifs are highly conserved, while the other characteristics are di- verse. It is notable that the Dof genes belonging to the same group or clade always display similar domain architecture, suggesting that they may have similar functions. Many cis - elements were also found in the upstream sequence of the ZmDofs , suggesting complicated regulatory relationship. We
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