Plant Molecular Biology

, Volume 65, Issue 1–2, pp 137–150 | Cite as

The HvNAC6 transcription factor: a positive regulator of penetration resistance in barley and Arabidopsis

  • Michael Krogh Jensen
  • Jesper Henrik Rung
  • Per Langkjaer Gregersen
  • Torben Gjetting
  • Anja Thoe Fuglsang
  • Michael Hansen
  • Nina Joehnk
  • Michael Foged Lyngkjaer
  • David B. Collinge


Pathogens induce the expression of many genes encoding plant transcription factors, though specific knowledge of the biological function of individual transcription factors remains scarce. NAC transcription factors are encoded in plants by a gene family with proposed functions in both abiotic and biotic stress adaptation, as well as in developmental processes. In this paper, we provide convincing evidence that a barley NAC transcription factor has a direct role in regulating basal defence. The gene transcript was isolated by differential display from barley leaves infected with the biotrophic powdery mildew fungus, Blumeria graminis f.sp. hordei (Bgh). The full-length cDNA clone was obtained using 5′-RACE and termed HvNAC6, due to its high similarity to the rice homologue, OsNAC6. Gene silencing of HvNAC6 during Bgh inoculation compromises penetration resistance in barley epidermal cells towards virulent Bgh. Complementing the effect of HvNAC6 gene silencing, transient overexpression of HvNAC6 increases the occurrence of penetration resistant cells towards Bgh attack. Quantitative RT-PCR shows the early and transient induction of HvNAC6 in barley epidermis upon Bgh infection. Additionally, our results show that the Arabidopsis HvNAC6 homologue ATAF1 is also induced by Bgh and the ataf1-1 mutant line shows decreased penetration resistance to this non-host pathogen. Collectively, these data suggest a conserved role of HvNAC6 and ATAF1 in the regulation of penetration resistance in monocots and dicots, respectively.


ATAF1 Blumeria graminis f.sp. hordei (BghExpression profiles HvNAC6 NAC transcription factor Penetration resistance 



Abscisic acid


Blumeria graminis f.sp. hordei


Base pair


Expressed sequence tag


Green fluorescence protein


Hypersensitive response


Hordeum vulgare




Primary germ tube


Rapid amplification of cDNA ends


RNA interference


Untranslated region



Accession numbers

HvNAC6 (AM500854) HvNAC1 (AM500855) HvNAC4 (AM500853) 



Authors would like to thank Drs Patrick Schweizer and Dimitar Doutchkov for the empty and HvSNAP34 overexpression pIPKA9 vectors, Michael Næsby for optimisation of RACE amplification procedure, NASC for providing the T-DNA insertion line, and Hans Thordal-Christensen for fruitful discussions and for reading the manuscript. MKJ was supported by a PhD scholarship from the University of Copenhagen, Faculty of Life Sciences (formerly the Royal Veterinary and Agricultural University) and research financed by a Danish Research Council grant “Cell specific analysis of host-plant responses to pathogens using a functional genomic approach” SJVF 23-03-0167 (to MFL and DBC).

Supplementary material


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Copyright information

© Springer Science+Business Media B.V. 2007

Authors and Affiliations

  • Michael Krogh Jensen
    • 1
  • Jesper Henrik Rung
    • 1
    • 2
  • Per Langkjaer Gregersen
    • 3
  • Torben Gjetting
    • 4
    • 5
  • Anja Thoe Fuglsang
    • 1
  • Michael Hansen
    • 1
  • Nina Joehnk
    • 1
  • Michael Foged Lyngkjaer
    • 4
  • David B. Collinge
    • 1
  1. 1.Department of Plant Biology, Faculty of Life SciencesUniversity of CopenhagenFrederiksberg CDenmark
  2. 2.NovozymesBagsvaerdDenmark
  3. 3.Department of Genetics and Biotechnology, Research Centre FlakkebjergUniversity of AarhusSlagelseDenmark
  4. 4.Department of Biosystems, Risoe National LaboratoryTechnical University of DenmarkRoskildeDenmark
  5. 5.The Kennedy Institute – National Eye ClinicGlostrupDenmark

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