Skip to main content

Maize peroxidase Px5 has a highly conserved sequence in inbreds resistant to mycotoxin producing fungi which enhances fungal and insect resistance


Mycotoxin presence in maize causes health and economic issues for humans and animals. Although many studies have investigated expression differences of genes putatively governing resistance to producing fungi, few have confirmed a resistance role, or examined putative resistance gene structure in more than a couple of inbreds. The pericarp expression of maize Px5 has previously been associated with resistance to Aspergillus flavus growth and insects in a set of inbreds. Genes from 14 different inbreds that included ones with resistance and susceptibility to A. flavus, Fusarium proliferatum, F. verticillioides and F. graminearum and/or mycotoxin production were cloned using high fidelity enzymes, and sequenced. The sequence of Px5 from all resistant inbreds was identical, except for a single base change in two inbreds, only one of which affected the amino acid sequence. Conversely, the Px5 sequence from several susceptible inbreds had several base variations, some of which affected amino acid sequence that would potentially alter secondary structure, and thus enzyme function. The sequence of the maize peroxidase Px5 common to inbreds resistant to mycotoxigenic fungi was overexpressed in maize callus. Callus transformants overexpressing the gene caused significant reductions in growth for fall armyworms, corn earworms, and F. graminearum compared to transformant callus with a β-glucuronidase gene. This study demonstrates rarer transcripts of potential resistance genes overlooked by expression screens can be identified by sequence comparisons. A role in pest resistance can be verified by callus expression of the candidate genes, which can thereby justify larger scale transformation and regeneration of transgenic plants expressing the resistance gene for further evaluation.

This is a preview of subscription content, access via your institution.

Fig. 1
Fig. 2
Fig. 3


  1. Brewbaker JL, Nagai C, Liu EH (1985) Genetic polymorphisms of 13 maize peroxidases. J Hered 76:159–167

    CAS  Google Scholar 

  2. Chen Z-Y, Rajasekaran K, Brown RL, Sayler RJ, Bhatnagar D (2015) Discovery and confirmation of genes/proteins associated with maize aflatoxin resistance. World Mycotox J 8:211–224

    Article  Google Scholar 

  3. Cleveland TE, Dowd P, Desjardins A, Bhatnagar D, Cotty P (2003) United States Department of Agriculture—Agricultural Research Service research on pre-harvest prevention of mycotoxins and mycotoxigenic fungi in US crops. Pest Manag Sci 59:629–642

    PubMed  CAS  Article  Google Scholar 

  4. Dowd PF (1994) Enhanced maize (Zea mays L.) pericarp browning: associations with insect resistance and involvement of oxidizing enzymes. J Chem Ecol 20:2777–2803

    PubMed  CAS  Article  Google Scholar 

  5. Dowd PF, Johnson ET (2005) Association of a specific cationic peroxidase isozyme with maize stress and disease resistance responses, genetic identification, and identification of a cDNA coding for the isozyme. J Agric Food Chem 53:4464–4470

    PubMed  CAS  Article  Google Scholar 

  6. Dowd PF, Norton RA (1995) Browning associated mechanisms of resistance to insects in corn callus tissue. J Chem Ecol 21:583–600

    PubMed  CAS  Article  Google Scholar 

  7. Dowd PF, White DG (2002) Corn earworm, Helicoverpa zea (Lepidoptera: Noctuidae) and other insect associated resistance in the maize inbred Tex6. J Econ Entomol 95:628–634

    PubMed  CAS  Article  Google Scholar 

  8. Dowd PF, Duvick JP, Rood T (1997) Comparative toxicity of allelochemicals and their enzymatic oxidation products to maize fungal pathogens, emphasizing Fusarium graminearum. Nat Toxins 5:180–185

    PubMed  CAS  Article  Google Scholar 

  9. Dowd PF, Johnson ET, Pinkerton TS (2007) Oral toxicity of β-N-acetyl hexosaminidase to insects. J Agric Food Chem 55:3421–3428

    PubMed  CAS  Article  Google Scholar 

  10. Dowd PF, Johnson ET, Pinkerton TS, Hughes SR (2008) Genetically modified plants containing plant-derived genes for broad spectrum insect control to reduce mycotoxins: bioactive proteins. In: Wolf T, Koch J (eds) Geneticially modified plants. Nova Science Publishers, NY, pp 127–153

    Google Scholar 

  11. Dowd PF, Johnson ET, Pinkerton TS (2010) Identification and properties of insect resistance-associated maize anionic peroxidases. Phytochemistry 71:1289–1297

    PubMed  CAS  Article  Google Scholar 

  12. Duroux L, Welinder KG (2003) The peroxidase gene family in plants: a phylogenetic overview. J Mol Evol 57:397–407

  13. Guillet-Claude C, Birolleau-Touchard C, Manicacci D, Rogowsky PM, Rigau J, Murigneux A, Martinant J-P, Barrie’re Y (2004) Nucleotide diversity of the ZmPox3 maize peroxidase gene: relationships between a MITE insertion in exon 2 and variation in forage maize digestibility. BMC Genet 5:19. doi:10.1186/1471-2156-5-19

    PubMed  PubMed Central  Article  Google Scholar 

  14. Hamblin AM, White DG (2000) Inheritance of resistance to Aspergillus ear rot and aflatoxin production of corn from Tex6. Phytopathology 90:292–296

    PubMed  CAS  Article  Google Scholar 

  15. Hawkins LK, Mylroie JE, Oliveira DA, Smith JS, Ozkan S, Windham GL, Williams WP, Warburton ML (2015) Characterization of the maize chitinase genes and their effect on Aspergillus flavus and aflatoxin accumulation resistance. PLoS ONE. doi:10.1371/journal.pone.0126125

    Google Scholar 

  16. Hecht M, Bromberg Y, Rost B (2013) News from the protein mutability landscape. J Mol Biol 425:3937–3948

    PubMed  CAS  Article  Google Scholar 

  17. Hooda V, Gundala PB, Chinthala P (2012) Sequence analysis and homology modeling of peroxidase from Medicago sativa. Bioinformation 8:974–979

    PubMed  PubMed Central  Article  Google Scholar 

  18. Jefferson RS, Burgess SM, Hirsh D (1986) β-glucuronidase from Escherichia coli as a gene fusion marker. Proc Natl Acad Sci (USA) 83:8447–8451

    CAS  PubMed Central  Article  Google Scholar 

  19. Johnson ET, Dowd PF, Pinkerton TS (2008) Altering plant secondary metabolism to achieve broad spectrum insect control and reduce mycotoxins. In: Wolf T, Koch J (eds) Geneticially modified plants. Nova Science Publishers, NY, pp 153–164

    Google Scholar 

  20. Lanubile A, Maschietto V, De Leonardis S, Battilani P, Paciola C, Marocco A (2015) Defense responses to mycotoxin producing fungi Fusarium proliferatum, F. subglutinans, and Aspergillus flavus in kernels of susceptible and resistant maize genotypes. Mol Plant Microbe Interact 28:546–557

    PubMed  CAS  Article  Google Scholar 

  21. Mahaptra R, Jampala SSM, Patel DR (2015) Induction of systemic acquired resistance in Zea mays L. by Aspergillus flavus and A. parasiticus derived elicitors. Arch Phytopathol Plant Prot 48:120–134

    Article  Google Scholar 

  22. Moore KG, Price MS, Boston RS, Weissinger AK, Payne GA (2004) A chitinase from Tex6 maize kernels inhibits growth of Aspergillus flavus. Phytopathology 94:82–87

    PubMed  CAS  Article  Google Scholar 

  23. Naumann TA, Wicklow DT (2010) Allozyme specific modification of a maize seed chitinase by a protein secreted by the fungal pathogen Stenocarpella maydis. Phytopathology 100:645–654

    PubMed  CAS  Article  Google Scholar 

  24. Oerke E-C (2006) Crop losses to pests. J Agric Sci 144:31–43

    Article  Google Scholar 

  25. Robens J, Cardwell KF (2005) The costs of mycotoxin management in the United States. In: Abbas H (ed) Aflatoxin and food safety. Taylor and Francis, NY, pp 1–12

    Chapter  Google Scholar 

  26. Schweizer P, Pokorny J, Abderhalden O, Dudler R (1999) A transient assay system for the functional assessment of defense-related genes in wheat. Mol Plant Microbe Interact 8:647–654

    Article  Google Scholar 

  27. Shiferaw B, Prasana BM, Hellin J, Bänziger M (2011) Crops that feed the world. 6. Past successes and future challenges to the role played by maize in global food security. Food Secur 3:307–327

    Article  Google Scholar 

  28. Tsuduki M, Takano T, Nakatsubo F, Yoshida K, Shinmyo A, Asao H (2006) Resistance to insect in transgenic Solanum plants expressing a peroxidase from horseradish. Plant Biotechnol. 23:71–74

    CAS  Article  Google Scholar 

  29. Wang G, Wang G, Zhang X, Wang F, Song R (2012) Isolation of high quality RNA from cereal seeds containing high levels of starch. Phytochem Anal 23:159–163

    PubMed  Article  Google Scholar 

  30. Warburton ML, Brooks TD, Windham GL, Williams WP (2011) Identification of QTL contributing resistance to aflatoxin accumulation in maize. Mol Bred. 27:491–499

    CAS  Article  Google Scholar 

  31. Welinder KG, Justesen AF, Kjærsgård, IVH, Jensen RB, Rasmussen S, Jespersen HM, Duroux L (2002) Structural diversity and transcription of class III peroxidases from Arabidopsis thaliana. Eur J Biochem 269:6063–6081

    PubMed  CAS  Article  Google Scholar 

  32. Xiang K, Zhang ZM, Reid LM, Zhu XY, Yuan GS, Pan GT (2010) A meta-analysis of QTL associated with ear rot resistance in maize. Maydica 55:281–290

    Google Scholar 

Download references


We thank the USDA-Agricultural Research Service, North Central Regional Plant Introduction Station, and P. W. Williams for providing seed; P. W. Williams for providing milk stage kernels, D. Schisler for providing the F. graminearum strain, D. Lee and M. Doehring for technical assistance, and A. P. Rooney and F. E. Vega for comments on prior versions of the manuscript.

Author information



Corresponding author

Correspondence to Patrick F. Dowd.

Ethics declarations

Conflict of interest

The authors declare that they have no conflicts of interest.

Additional information

Mention of trade names or commercial products in the article is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the US Department of Agriculture. USDA is an equal opportunity provider and employer.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Dowd, P.F., Johnson, E.T. Maize peroxidase Px5 has a highly conserved sequence in inbreds resistant to mycotoxin producing fungi which enhances fungal and insect resistance. J Plant Res 129, 13–20 (2016).

Download citation


  • Peroxidase
  • Maize
  • Mycotoxin
  • Spodoptera
  • Helicoverpa
  • Fusarium