Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2024 Aug 7;14(8):958.
doi: 10.3390/biom14080958.

Expression of Foxtail Millet bZIP Transcription Factor SibZIP67 Enhances Drought Tolerance in Arabidopsis

Xinfeng Jia  1 , Hanchi Gao  1 , Lingxin Zhang  1 , Wei Tang  1   2   3 , Guo Wei  4 , Juan Sun  1   2   3 , Wangdan Xiong  1   2   3
Affiliations

Expression of Foxtail Millet bZIP Transcription Factor SibZIP67 Enhances Drought Tolerance in Arabidopsis

Xinfeng Jia et al. Biomolecules. .

Abstract

Foxtail millet is a drought-tolerant cereal and forage crop. The basic leucine zipper (bZIP) gene family plays important roles in regulating plant development and responding to stresses. However, the roles of bZIP genes in foxtail millet remain largely uninvestigated. In this study, 92 members of the bZIP transcription factors were identified in foxtail millet and clustered into ten clades. The expression levels of four SibZIP genes (SibZIP11, SibZIP12, SibZIP41, and SibZIP67) were significantly induced after PEG treatment, and SibZIP67 was chosen for further analysis. The studies showed that ectopic overexpression of SibZIP67 in Arabidopsis enhanced the plant drought tolerance. Detached leaves of SibZIP67 overexpressing plants had lower leaf water loss rates than those of wild-type plants. SibZIP67 overexpressing plants improved survival rates under drought conditions compared to wild-type plants. Additionally, overexpressing SibZIP67 in plants displayed reduced malondialdehyde (MDA) levels and enhanced activities of antioxidant enzymes, including catalase (CAT), superoxide dismutase (SOD), and peroxidase (POD) under drought stress. Furthermore, the drought-related genes, such as AtRD29A, AtRD22, AtNCED3, AtABF3, AtABI1, and AtABI5, were found to be regulated in SibZIP67 transgenic plants than in wild-type Arabidopsis under drought conditions. These data suggested that SibZIP67 conferred drought tolerance in transgenic Arabidopsis by regulating antioxidant enzyme activities and the expression of stress-related genes. The study reveals that SibZIP67 plays a beneficial role in drought response in plants, offering a valuable genetic resource for agricultural improvement in arid environments.

Keywords: Setaria italica; bZIP; drought; transcription factor.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflicts of interest.

Figures

Figure 1
Figure 1
Phylogenetic analysis of bZIP proteins in foxtail millet and rice.
Figure 2
Figure 2
Differential expression genes in foxtail millet leave after PEG treatment. (A) Volcanic maps after PEG treatment. Green and red dots indicate down-regulated DEGs for log2(FC) ≤ −1 and up-regulated DEGs for log2(FC) ≥ 1, respectively. Black dots indicate no significant differences between transcriptomes. (B) Venn diagrams of co-regulated genes at 2 h and 6 h after PEG treatment. (C) Regulated SibZIP genes after drought treatment at both 2 h and 6 h. D refers to the expression level under PEG treatment, and CK refers to the control. The experiment contains three biological replicates.
Figure 2
Figure 2
Differential expression genes in foxtail millet leave after PEG treatment. (A) Volcanic maps after PEG treatment. Green and red dots indicate down-regulated DEGs for log2(FC) ≤ −1 and up-regulated DEGs for log2(FC) ≥ 1, respectively. Black dots indicate no significant differences between transcriptomes. (B) Venn diagrams of co-regulated genes at 2 h and 6 h after PEG treatment. (C) Regulated SibZIP genes after drought treatment at both 2 h and 6 h. D refers to the expression level under PEG treatment, and CK refers to the control. The experiment contains three biological replicates.
Figure 3
Figure 3
The conserved domain of SibZIP67 and expression pattern of SibZIP67 in foxtail millet. (A) The conserved domain of SibZIP67 and its closely related sequences in rice, Arabidopsis, green foxtail, and sorghum. (B) Expression levels of SibZIP67 in root, leaf, and stem under unstressed conditions. (C) The expression level of SibZIP67 in roots after PEG treatment. (D) The expression level of SibZIP67 in shoots after PEG treatment. The baseline expression of the SibZIP67 gene at each time point in the control group was set to a value of 1. The relative expression levels of the SibZIP67 gene in response to PEG treatment were ascertained by comparing the fold changes in gene expression between the treated samples and their corresponding controls at each respective time point. Lowercase letters indicate a significant difference at p < 0.05. Each experiment contains three biological replicates, and each with two technical replicates (means of n = 6 ± SD).
Figure 4
Figure 4
The germination rates of SibZIP67 overexpressing lines and WT under mannitol treatment. (A) Comparison of germination of SibZIP67 overexpressing lines and WT on 1/2 MS medium containing 0, 200, and 300 mM mannitol for 3 days. (B) Seed germination rates of SibZIP67 overexpressing lines and WT on 1/2 MS medium containing 0, 200, and 300 mM mannitol. Data represent mean values ± SD from four biological replicates (n = 72). ** indicates p < 0.01.
Figure 5
Figure 5
Phenotype and root length of SibZIP67 overexpressing lines on a vertical plate under mannitol treatment. (A) Phenotypes of SibZIP67 overexpressing lines and WT on 1/2 MS medium containing 0, 200, and 300 mM mannitol for 7 days. (B) Root length between transgenic and WT seedlings on 1/2 MS medium containing 0, 200, and 300 mM mannitol for 7 days. All data were analyzed for five biological replicates (n = 30). Lowercase letters indicate a significant difference at p < 0.05.
Figure 6
Figure 6
Drought tolerance of SibZIP67 overexpressing lines. (A) Phenotype of SibZIP67 overexpressing lines and WT after drought treatment. (B) Water loss rate of detached leaves. (C) Survival rate statistics after withholding water for 12 days and re-watering for 3 days. (D) MDA content in the leaves of transgenic and WT plants under drought stress. (E–G) Activities of POD (E), CAT (F), and SOD (G) activities of transgenic and WT plants under drought stress. Data in (B,C): means of n = 30 ± SD from three independent experiments. Data in (D–G): means of n = 6 ± SD from three independent experiments. * and ** indicate p < 0.01 and p < 0.01, respectively.
Figure 6
Figure 6
Drought tolerance of SibZIP67 overexpressing lines. (A) Phenotype of SibZIP67 overexpressing lines and WT after drought treatment. (B) Water loss rate of detached leaves. (C) Survival rate statistics after withholding water for 12 days and re-watering for 3 days. (D) MDA content in the leaves of transgenic and WT plants under drought stress. (E–G) Activities of POD (E), CAT (F), and SOD (G) activities of transgenic and WT plants under drought stress. Data in (B,C): means of n = 30 ± SD from three independent experiments. Data in (D–G): means of n = 6 ± SD from three independent experiments. * and ** indicate p < 0.01 and p < 0.01, respectively.
Figure 7
Figure 7
Transcript levels of stress-related marker genes in SibZIP67 overexpressing lines and WT plant. Leaves were collected when the soil moisture content was 30%. Each experiment contains three biological replicates, and each with two technical replicates (means of n = 6 ± SD). ** indicates p < 0.01.
Figure 7
Figure 7
Transcript levels of stress-related marker genes in SibZIP67 overexpressing lines and WT plant. Leaves were collected when the soil moisture content was 30%. Each experiment contains three biological replicates, and each with two technical replicates (means of n = 6 ± SD). ** indicates p < 0.01.
Figure 8
Figure 8
Proposed model of the positive roles of SibZIP67 in drought tolerance.
See this image and copyright information in PMC

Similar articles

See all similar articles

References

    1. Gong Z., Xiong L., Shi H., Yang S., Herrera-Estrella L.R., Xu G., Chao D., Li J., Wang P., Qin F., et al. Plant abiotic stress response and nutrient use efficiency. Sci. China Life Sci. 2020;63:635–674. doi: 10.1007/s11427-020-1683-x. - DOI - PubMed
    1. Nykiel M., Gietler M., Fidler J., Prabucka B., Labudda M. Abiotic stress signaling and responses in plants. Plants. 2023;12:3405. doi: 10.3390/plants12193405. - DOI - PMC - PubMed
    1. Vinocur B., Altman A. Recent advances in engineering plant tolerance to abiotic stress: Achievements and limitations. Curr. Opin. Biotechnol. 2005;16:123–132. doi: 10.1016/j.copbio.2005.02.001. - DOI - PubMed
    1. Huang G., Ma S., Bai L., Zhang L., Ma H., Jia P., Liu J., Zhong M., Guo Z. Signal transduction during cold, salt, and drought stresses in plants. Mol. Biol. Rep. 2012;39:969–987. doi: 10.1007/s11033-011-0823-1. - DOI - PubMed
    1. Strader L., Weijers D., Wagner D. Plant transcription factors—Being in the right place with the right company. Curr. Opin. Plant Biol. 2022;65:102136. doi: 10.1016/j.pbi.2021.102136. - DOI - PMC - PubMed

MeSH terms

Substances

LinkOut - more resources