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 May 22;25(11):5621.
doi: 10.3390/ijms25115621.

Oil Palm AP2 Subfamily Gene EgAP2.25 Improves Salt Stress Tolerance in Transgenic Tobacco Plants

Lixia Zhou  1   2 , Hongxing Cao  1   2 , Xianhai Zeng  1   2 , Qiufei Wu  1   2 , Qihong Li  1   2 , Jerome Jeyakumar John Martin  1   2 , Dengqiang Fu  1   2 , Xiaoyu Liu  1   2 , Xinyu Li  1   2 , Rui Li  1   2 , Jianqiu Ye  1   2
Affiliations

Oil Palm AP2 Subfamily Gene EgAP2.25 Improves Salt Stress Tolerance in Transgenic Tobacco Plants

Lixia Zhou et al. Int J Mol Sci. .

Abstract

AP2/ERF transcription factor genes play an important role in regulating the responses of plants to various abiotic stresses, such as cold, drought, high salinity, and high temperature. However, less is known about the function of oil palm AP2/ERF genes. We previously obtained 172 AP2/ERF genes of oil palm and found that the expression of EgAP2.25 was significantly up-regulated under salinity, cold, or drought stress conditions. In the present study, the sequence characterization and expression analysis for EgAP2.25 were conducted, showing that it was transiently over-expressed in Nicotiana tabacum L. The results indicated that transgenic tobacco plants over-expressing EgAP2.25 could have a stronger tolerance to salinity stress than wild-type tobacco plants. Compared with wild-type plants, the over-expression lines showed a significantly higher germination rate, better plant growth, and less chlorophyll damage. In addition, the improved salinity tolerance of EgAP2.25 transgenic plants was mainly attributed to higher antioxidant enzyme activities, increased proline and soluble sugar content, reduced H2O2 production, and lower MDA accumulation. Furthermore, several stress-related marker genes, including NtSOD, NtPOD, NtCAT, NtERD10B, NtDREB2B, NtERD10C, and NtP5CS, were significantly up-regulated in EgAP2.25 transgenic tobacco plants subjected to salinity stress. Overall, over-expression of the EgAP2.25 gene significantly enhanced salinity stress tolerance in transgenic tobacco plants. This study lays a foundation for further exploration of the regulatory mechanism of the EgAP2.25 gene in conferring salinity tolerance in oil palm.

Keywords: EgAP2.25 gene; oil palm; physiological and biochemical indexes; salinity stress; stress marker genes; tobacco.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflicts of interest.

Figures

Figure 1
Figure 1
Character of oil palm EgAP2.25. (a) Conserved AP2/ERF domains of EgAP2.25 protein. Red box represented conserved domain 1 and green box represented conserved domain 2. (b) Structure of EgAP2.25 gene. (c) Motif of EgAP2.25 protein. (d) Distribution and function of cis-acting regulatory elements in the promoter of EgAP2.25. (e) The tertiary structure of EgAP2.25 protein. Rose red represented random coil, red represented β-sheet and blue represented α-helix. (f) Expression of EgAP2.25 gene under cold, salt, and drought stresses.
Figure 2
Figure 2
Steps involved in genetic transformation of tobacco. (a) Callus formation on media. (b) Rooted transgenic plant. (c,d) Pot-grown transgenic plant (T0 lines). (e) T1 transgenic plants. (f) T2 transgenic plants. (g) T3 transgenic plants.
Figure 3
Figure 3
Profile of transgenic tobacco plants. (a) PCR results of T0 EgAP2.25 transgenic tobacco lines. (b) Semi-quantitative RT-PCR analysis of EgAP2.25 (124 bp) gene in WT, T1, T2, and T3 transgenic tobacco lines.
Figure 4
Figure 4
Seed germination and seedling growth of wide and transgenic tobacco. (a) Germination of seeds treated with 0, 100, 200, 300 mM NaCl. (b–e) Germination percentage, root length, and dry/fresh weight of WT and transgenic tobacco at 0~300 mM NaCl, respectively. Numerical values were means ± SD (n = 3), ** represents p < 0.01, and * represents p < 0.05.
Figure 5
Figure 5
Effect of EgAP2.25 gene expression under salt stress. (a) Comparative observations of root, shoot, and leaf growth between WT and transgenic tobacco lines. (b) Phenotypes of WT and transgenic EgAP2.25 tobacco lines watered with 200 mM of NaCl solution.
Figure 6
Figure 6
Antioxidant enzyme activity in EgAP2.25 transgenic and WT tobacco plant leaves under 0, 100, 200, and 300 mM NaCl stress.* represents p < 0.05.
Figure 7
Figure 7
Changes in MDA (a), H2O2 (b), proline (c), soluble sugar (d), chlorophyll content (e), and relative conductivity (f) in EgAP2.25-over-expressed and WT tobacco plants under salt conditions. ** represents p < 0.01, and * represents p < 0.05.
Figure 8
Figure 8
qPCR validation of EgAP2.25 gene expression in transgenic tobacco tissues with 200 mM NaCl solution. ** means p < 0.01.
Figure 9
Figure 9
Antioxidant enzyme genes expression in WT and transgenic tobacco with 200 mM NaCl solution. * represents p < 0.05 and ** represents p < 0.01.
Figure 10
Figure 10
Schematic representation of the background information of the EgAP2.25 gene.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

References

    1. Baillo E.H., Kimotho R.N., Zhang Z., Xu P. Transcription factors associated with abiotic and biotic stress tolerance and their potential for crops improvement. Genes. 2019;10:771. doi: 10.3390/genes10100771. - DOI - PMC - PubMed
    1. Van-Zelm E., Zhang Y., Testerink C. Salt tolerance mechanisms of plants. Annu. Rev. Plant Biol. 2020;71:403–433. doi: 10.1146/annurev-arplant-050718-100005. - DOI - PubMed
    1. Li J., Liu J., Zhu T., Zhao C., Li L., Chen M. The role of melatonin in salt stress reponses. Int. J. Mol. Sci. 2019;20:1735. doi: 10.3390/ijms20071735. - DOI - PMC - PubMed
    1. Park H.J., Kim W.Y., Yun D.J. A new insight of salt stress signaling in plant. Mol. Cells. 2019;2:447–459. - PMC - PubMed
    1. Avin-Wittenberg T. Autophagy and its role in plant abiotic stress management. Plant Cell Environ. 2019;42:1045–1053. doi: 10.1111/pce.13404. - DOI - PubMed

MeSH terms