Cereal Research Communications

, Volume 47, Issue 2, pp 216–227 | Cite as

Salt Stress Induces Genotype-specific DNA Hypomethylation in ZmEXPB2 and ZmXET1 Genes in Maize

  • F. Kaleem
  • M. Shahzad
  • G. Shabir
  • K. Aslam
  • S. M. Shah
  • A. R. KhanEmail author


Maize, a moderately salt sensitive crop, first experiences osmotic stress that cause reduction in plant growth under salt stress. Fluctuation in cell wall elongation is one of the reasons of this reduction. Along with others, two important proteins expansins and xyloglucan endotransglucosylase are involved in regulation of cell wall elasticity, but the role of epigenetic mechanisms in regulating the cell wall related genes is still elusive. The present study was conducted with the aim of understanding the role of DNA methylation in regulating ZmEXPB2 and ZmXET1 genes. One salt sensitive and one salt tolerant maize cultivar was grown under hydroponic conditions at different levels of salt stress: T1 = 1 mM (control), T2 = 100 mM and T3 = 200 mM in three replicates. DNA and RNA were extracted from roots. After bisulfite treatment, Methyl Sensitive PCR was used for the DNA methylation analysis. It was revealed that fragment in promoter of ZmEXPB2 gene showed high level of DNA methylation under T1 in both varieties. Comparison of different stress treatments revealed decrease in DNA methylation with the increase in salt stress, significantly lower methylation appearing in T3. Similarly, the fragment in promoter of ZmXET1 gene also showed high levels of DNA methylation in T1. When different treatments were analysed, this gene significantly hypomethylated at T2 which continued to decrease in T3 in sensitive variety but remain stable in tolerant variety. Although, further in-depth analysis is required, our results demonstrate region-specific and genotype-specific methylation shift in the promoter of the ZmEXPB2 and ZmXET1 genes when subjected to the salt stress confirming the epigenetic regulation of these genes under stress conditions.


salinity DNA methylation expansins xyloglucan endotransglucosylase Zea mays L. 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Supplementary material

42976_2019_4702216_MOESM1_ESM.pdf (199 kb)
Supplementary material, approximately 204 KB.


  1. Baek, D., Jiang, J., Chung, J.-S., Wang, B., Chen, J., Xin, Z., Shi, H. 2011. Regulated AtHKT1 gene expression by a distal enhancer element and DNA methylation in the promoter plays an important role in salt tolerance. Plant Cell Physiol. 52:149–161.CrossRefGoogle Scholar
  2. Bjornson, M., Dandekar, A., Dehesh, K. 2016. Determinants of timing and amplitude in the plant general stress response. J. Integr. Plant Biol. 58:119–126.CrossRefGoogle Scholar
  3. Cedar, H., Bergman, Y. 2009. Linking DNA methylation and histone modification: patterns and paradigms. Nat. Rev. Genet. 10:295–304.CrossRefGoogle Scholar
  4. Chinnusamy, V., Jagendorf, A., Zhu, J.-K. 2005. Understanding and improving salt tolerance in plants. Crop Sci. 45:437–448.CrossRefGoogle Scholar
  5. Cho, H.-T., Cosgrove, D.J. 2000. Altered expression of expansin modulates leaf growth and pedicel abscission in Arabidopsis thaliana. Proc. Natl. Acad. Sci. 97:9783–9788.CrossRefGoogle Scholar
  6. Choi, C.-S., Sano, H. 2007. Abiotic-stress induces demethylation and transcriptional activation of a gene encoding a glycerophosphodiesterase-like protein in tobacco plants. Mol. Genet. Genomics. 277:589–600.CrossRefGoogle Scholar
  7. Choi, D., Lee, Y., Cho, H.-T., Kende, H. 2003. Regulation of expansin gene expression affects growth and development in transgenic rice plants. Plant Cell 15:1386–1398.CrossRefGoogle Scholar
  8. Cosgrove, D.J. 2000. Loosening of plant cell walls by expansins. Nature 407:321–326.CrossRefGoogle Scholar
  9. Cosgrove, D.J., Li, L.C., Cho, H.-T., Hoffmann-Benning, S., Moore, R.C., Blecker, D. 2002. The growing world of expansins. Plant Cell Physiol. 43:1436–1444.CrossRefGoogle Scholar
  10. de Azevedo Neto, A.D., Prisco, J.T., Enéas-Filho, J., Abreu, C.E.B. de, Gomes-Filho, E. 2006. Effect of salt stress on antioxidative enzymes and lipid peroxidation in leaves and roots of salt-tolerant and salt-sensitive maize genotypes. Environ. Exp. Bot. 56:87–94.CrossRefGoogle Scholar
  11. El Sayed, H.E.S.A. 2011. Influence of salinity stress on growth parameters, photosynthetic activity and cytological studies of Zea mays, L. plant using hydrogel polymer. Agric. Biol. J. N. Am. 2:907–920.CrossRefGoogle Scholar
  12. Fei, Y., Xue, Y., Du, P., Yang, S., Deng, X. 2017. Expression analysis and promoter methylation under osmotic and salinity stress of TaGAPC1 in wheat (Triticum aestivum L). Protoplasma 254:987–996.CrossRefGoogle Scholar
  13. Fortmeier, R., Schubert, S. 1995. Salt tolerance of maize (Zea mays L.): the role of sodium exclusion. Plant Cell Environ. 18:1041–1047.CrossRefGoogle Scholar
  14. Galvan-Ampudia, C.S., Julkowska, M.M., Darwish, E., Gandullo, J., Korver, R.A., Brunoud, G., Haring, M.A., Munnik, T., Vernoux, T., Testerink, C. 2013. Halotropism is a response of plant roots to avoid a saline environment. Curr. Biol. 23:2044–2050.CrossRefGoogle Scholar
  15. Geilfus, C.-M., Ober, D., Eichacker, L.A., Mühling, K.H., Zörb, C. 2015. Down-regulation of ZmEXPB6 (Zea mays β-expansin 6) protein is correlated with salt-mediated growth reduction in the leaves of Z. mays L. J. Biol. Chem. 290:11235–11245.CrossRefGoogle Scholar
  16. Geilfus, C.-M., Zörb, C., Neuhaus, C., Hansen, T., Lüthen, H., Mühling, K.H. 2011. Differential transcript expression of wall-loosening candidates in leaves of maize cultivars differing in salt resistance. J. Plant Growth Regul. 30:387–395.CrossRefGoogle Scholar
  17. González, R.M., Ricardi, M.M., Iusem, N.D. 2013. Epigenetic marks in an adaptive water stress-responsive gene in tomato roots under normal and drought conditions. Epigenetics 8:864–872.CrossRefGoogle Scholar
  18. Khan, A.R., Enjalbert, J., Marsollier, A.-C., Rousselet, A., Goldringer, I., Vitte, C. 2013. Vernalization treatment induces site-specific DNA hypermethylation at the VERNALIZATION-A1 (VRN-A1) locus in hexaploid winter wheat. BMC Plant Biol. 13:209.CrossRefGoogle Scholar
  19. Kosová, K., Prášil, I.T., Vítámvás, P. 2013. Protein contribution to plant salinity response and tolerance acquisition. Int. J. Mol. Sci. 14:6757–6789.CrossRefGoogle Scholar
  20. Kumar, S., Beena, A.S., Awana, M., Singh, A. 2017. Salt-induced tissue-specific cytosine methylation down-regulates expression of HKT genes in contrasting wheat (Triticum aestivum L.) genotypes. DNA Cell Biol. 36:283–294.CrossRefGoogle Scholar
  21. Lee, D.-K., Ahn, J.H., Song, S.-K., Choi, Y.D., Lee, J.S. 2003. Expression of an expansin gene is correlated with root elongation in soybean. Plant Physiol. 131:985–997.CrossRefGoogle Scholar
  22. Li, H., Yan, S., Zhao, L., Tan, J., Zhang, Q., Gao, F., Wang, P., Hou, H., Li, L. 2014. Histone acetylation associated up-regulation of the cell wall related genes is involved in salt stress induced maize root swelling. BMC Plant Biol. 14:105.CrossRefGoogle Scholar
  23. Liu, T., Van Staden, J., Cress, W.A. 2000. Salinity induced nuclear and DNA degradation in meristematic cells of soybean (Glycine max L.) roots. Plant Growth Regul. 30:49–54.CrossRefGoogle Scholar
  24. Menezes-Benavente, L., Kernodle, S.P., Margis-Pinheiro, M., Scandalios, J.G. 2004. Salt-induced antioxidant metabolism defenses in maize (Zea mays L.) seedlings. Redox Rep. 9:29–36.CrossRefGoogle Scholar
  25. Paszkowski, J., Whitham, S.A. 2001. Gene silencing and DNA methylation processes. Curr. Opin. Plant Biol. 4:123–129.CrossRefGoogle Scholar
  26. Paul, A., Dasgupta, P., Roy, D., Chaudhuri, S. 2017. Comparative analysis of histone modifications and DNA methylation at OsBZ8 locus under salinity stress in IR64 and Nonabokra rice varieties. Plant Mol. Biol. 95:63–88CrossRefGoogle Scholar
  27. Pecinka, A., Dinh, H.Q., Baubec, T., Rosa, M., Lettner, N., Mittelsten Scheid, O. 2010. Epigenetic regulation of repetitive elements is attenuated by prolonged heat stress in Arabidopsis. Plant Cell. 22:3118–3129.CrossRefGoogle Scholar
  28. Pitann, B., Kranz, T., Mühling, K.H. 2009/a. The apoplastic pH and its significance in adaptation to salinity in maize (Zea mays L.): Comparison of fluorescence microscopy and pH-sensitive microelectrodes. Plant Sci. 176:497–504.CrossRefGoogle Scholar
  29. Pitann, B., Schubert, S., Mühling, K.H. 2009/b. Decline in leaf growth under salt stress is due to an inhibition of H+-pumping activity and increase in apoplastic pH of maize leaves. J. Plant Nutr. Soil Sci. 172:535–543.CrossRefGoogle Scholar
  30. Shahzad, M., Witzel, K., Zörb, C., Mühling, K.H. 2012. Growth-related changes in subcellular ion patterns in maize leaves (Zea mays L.) under salt stress. J. Agron. Crop Sci. 198:46–56.CrossRefGoogle Scholar
  31. Song, Y., Ji, D., Li, S., Wang, P., Li, Q., Xiang, F. 2012. The dynamic changes of DNA methylation and histone modifications of salt responsive transcription factor genes in soybean. PLOS One. 7:e41274.CrossRefGoogle Scholar
  32. SüMER, A., Zörb, C., Yan, F., Schubert, S. 2004. Evidence of sodium toxicity for the vegetative growth of maize (Zea mays L.) during the first phase of salt stress. J. Appl. Bot. 78:135–139.Google Scholar
  33. Szalai, G., Janda, T. 2009. Effect of salt stress on the salicylic acid synthesis in young maize (Zea mays L.) plants. J. Agron. Crop Sci. 195:165–171.CrossRefGoogle Scholar
  34. Takeda, T., Fry, S.C. 2004. Control of xyloglucan endotransglucosylase activity by salts and anionic polymers. Planta 219:722–732.CrossRefGoogle Scholar
  35. Vincent, D., Ergül, A., Bohlman, M.C., Tattersall, E.A.R., Tillett, R.L., Wheatley, M.D., Woolsey, R., Quilici, D.R., Joets, J., Schlauch, K., Schooley, D.A., Cushman, J.C., Cramer, G.R. 2007. Proteomic analysis reveals differences between Vitis vinifera L. cv. Chardonnay and cv. Cabernet Sauvignon and their responses to water deficit and salinity. J. Exp. Bot. 58:1873–1892.CrossRefGoogle Scholar
  36. Wu, Y., Jeong, B.-R., Fry, S.C., Boyer, J.S. 2005. Change in XET activities, cell wall extensibility and hypocotyl elongation of soybean seedlings at low water potential. Planta 220:593–601.CrossRefGoogle Scholar
  37. Xu, R., Wang, Y., Zheng, H., Lu, W., Wu, C., Huang, J., Yan, K., Yang, G., Zheng, C. 2015. Salt-induced transcription factor MYB74 is regulated by the RNA-directed DNA methylation pathway in Arabidopsis. J. Exp. Bot. 66:5997–6008.CrossRefGoogle Scholar
  38. Zörb, C., Mühling, K.H., Kutschera, U., Geilfus, C.-M. 2015. Salinity stiffens the epidermal cell walls of saltstressed maize leaves: Is the epidermis growth-restricting? PLOS One. 10:e0118406.CrossRefGoogle Scholar

Copyright information

© Akadémiai Kiadó, Budapest 2019

Authors and Affiliations

  • F. Kaleem
    • 1
  • M. Shahzad
    • 1
  • G. Shabir
    • 2
  • K. Aslam
    • 2
  • S. M. Shah
    • 1
  • A. R. Khan
    • 1
    Email author
  1. 1.Department of Environmental SciencesCOMSATS UniversityIslamabad, Abbottabad CampusPakistan
  2. 2.Institute of Molecular Biology and BiotechnologyBahauddin Zakariya UniversityMultanPakistan

Personalised recommendations