Annals of Microbiology

, Volume 63, Issue 2, pp 763–769 | Cite as

5-Azacytidine inhibits aflatoxin biosynthesis in Aspergillus flavus

Original Article
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Abstract

Aflatoxins, mainly produced by Aspergillus flavus and A. parasiticus, are a group of potent mycotoxins with carcinogenic, hepatotoxic, and immunosuppressive properties. Many studies have been devoted to investigating their biosynthesis mechanism since they were discovered half a century ago. 5-Azacytidine (5-AC), a derivative of the nucleoside cytidine and an inactivator of DNA methyltransferase, is widely used for studies in epigenetics and cancer biology, and has also been used for studying secondary metabolism in fungi. In this study, 5-AC was applied to investigate its effect on the development and aflatoxin biosynthesis of A. flavus. The results indicate that 5-AC inhibits the ability to produce aflatoxin and also causes a fluffy aconidial phenotype. Further studies revealed that 5-AC affects gene expression of A. flavus to a limited degree, and the unique homolog of DNA methyltransferase gene (DmtA) expressed constitutively during different developmental stages of A. flavus irrespective of 5-AC. This work may provide some basic data to elucidate the role of 5-AC in aflatoxin biosynthesis and the development of A. flavus.

Keywords

5-azacytidine Aflatoxin Aspergillus flavus Gene expression 
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Notes

Acknowledgements

This work was supported by National Natural Science Foundation of China (Grant no. 31170044 and 30870024) and Science and Technology Planning Project of Guangdong Province, China (grant no. 2011B020305005). We thank Prof. T.W. Hill (Rhodes College, Memphis, TN, USA) for suggestions and amendments to the paper.

References

  1. Ben-Ami R, Varga V, Lewis RE, May GS, Nierman WC, Kontoyiannis DP (2010) Characterization of a 5-azacytidine-induced developmental Aspergillus fumigatus variant. Virulence 1:164–173PubMedCrossRefGoogle Scholar
  2. He ZM, Price MS, Obrian GR, Georgianna DR, Payne GA (2007) Improved protocols for functional analysis in the pathogenic fungus Aspergillus flavus. BMC Microbiol 7:104PubMedCrossRefGoogle Scholar
  3. Hicks JK, Yu JH, Keller NP, Adams TH (1997) Aspergillus sporulation and mycotoxin production both require inactivation of the FadA G alpha protein-dependent signaling pathway. EMBO J 16:4916–4923PubMedCrossRefGoogle Scholar
  4. Holmes RA, Boston RS, Payne GA (2008) Diverse inhibitors of aflatoxin biosynthesis. Appl Microbiol Biotechnol 78:559–572PubMedCrossRefGoogle Scholar
  5. Kensler TW, Roebuck BD, Wogan GN, Groopman JD (2011) Aflatoxin: a 50-year odyssey of mechanistic and translational toxicology. Toxicol Sci 120:S28–S48PubMedCrossRefGoogle Scholar
  6. Komashko VM, Farnham PJ (2010) 5-Azacytidine treatment reorganizes genomic histone modification patterns. Epigenetics 5:229–240CrossRefGoogle Scholar
  7. Kritsky MS, Russo VE, Filippovich SY, Afanasieva TP, Bachurina GP (2002) The opposed effect of 5-azacytidine and light on the development of reproductive structures in Neurospora crassa. Photochem Photobiol 75:79–83PubMedCrossRefGoogle Scholar
  8. Lee SE, Mahoney NE, Campbell BC (2002) Inhibition of aflatoxin B1 biosynthesis by piperlongumine isolated from Piper longum L. J Microbiol Biotechnol 12:679–682Google Scholar
  9. Liu SY, Lin JQ, Wu HL, Wang CC, Huang SJ, Luo YF, Sun JH, Zhou JX, Yan SJ, He JG, Wang J, He ZM (2012) Bisulfite sequencing reveals that Aspergillus flavus holds a hollow in DNA methylation. Plos One 7:e30349PubMedCrossRefGoogle Scholar
  10. Lyko F, Brown R (2005) DNA methyltransferase inhibitors and the development of epigenetic cancer therapies. J Natl Cancer Inst 97:1498–1506PubMedCrossRefGoogle Scholar
  11. Norton RA (1997) Effect of carotenoids on aflatoxin B1 synthesis by Aspergillus flavus. Phytopathology 87:814–821PubMedCrossRefGoogle Scholar
  12. Salter MG, Conlon HE (2007) Extraction of plant RNA. Methods Mol Biol 362:309–314PubMedCrossRefGoogle Scholar
  13. Song DK, Karr AL (1993) Soybean phytoalexin, glyceollin, prevents accumulation of aflatoxin B1 in cultures of Aspergillus flavus. J Chem Ecol 19:1983–1994CrossRefGoogle Scholar
  14. Tamame M, Antequera F, Villanueva JR, Santos T (1983a) 5-Azacytidine Induces heritable biochemical and developmental changes in the fungus Aspergillus niger. J Gen Microbiol 129:2585–2594Google Scholar
  15. Tamame M, Antequera F, Villanueva JR, Santos T (1983b) High-frequency conversion to a “fluffy” developmental phenotype in Aspergillus spp. by 5-azacytidine treatment: evidence for involvement of a single nuclear gene. Mol Cell Biol 3:2287–2297PubMedGoogle Scholar
  16. Tamame M, Antequera F, Santos E (1988) Developmental characterization and chromosomal mapping of the 5-azacytidine-sensitive fluF locus of Aspergillus nidulans. Mol Cell Biol 8:3043–3050PubMedGoogle Scholar
  17. van West P, Shepherd SJ, Walker CA, Li S, Appiah AA, Grenville-Briggs LJ, Govers F, Gow NA (2008) Internuclear gene silencing in Phytophthora infestans is established through chromatin remodelling. Microbiology 154:1482–1490PubMedCrossRefGoogle Scholar
  18. Wada H, Kagoshima M, Ito K, Barnes PJ, Adcock IM (2005) 5-Azacytidine suppresses RNA polymerase II recruitment to the SLPI gene. Biochem Biophys Res Commun 331(1):93–99PubMedCrossRefGoogle Scholar
  19. Wilkinson JR, Kale SP, Bhatnagar D, Yu J, Ehrlich KC (2011) Expression profiling of non-aflatoxigenic Aspergillus parasiticus mutants obtained by 5-azacytosine treatment or serial mycelial transfer. Toxins 3:932–948PubMedCrossRefGoogle Scholar
  20. Williams RB, Henrikson JC, Hoover AR, Lee AE, Cichewicz RH (2008) Epigenetic remodeling of the fungal secondary metabolome. Org Biomol Chem 6:1895–1490PubMedCrossRefGoogle Scholar
  21. Yu J, Chang PK, Ehrlich KC, Cary JW, Bhatnagar D, Cleveland TE, Payne GA, Linz JE, Woloshuk CP, Bennett JW (2004) Clustered pathway genes in aflatoxin biosynthesis. Appl Environ Microbiol 70:1253–1262PubMedCrossRefGoogle Scholar

Copyright information

© Springer-Verlag and the University of Milan 2012

Authors and Affiliations

  1. 1.MOE Key Laboratory of Aquatic Product Safety, School of Life SciencesSun Yat-sen UniversityGuangzhouPeople’s Republic of China
  2. 2.School of Life SciencesSun Yat-sen UniversityGuangzhouPeople’s Republic of China

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