The wheat calcium-dependent protein kinase TaCPK7-D positively regulates host resistance to sharp eyespot disease

Mol Plant Pathol. 2016 Oct;17(8):1252-64. doi: 10.1111/mpp.12360. Epub 2016 Apr 21.


Sharp eyespot, caused mainly by the necrotrophic fungus Rhizoctonia cerealis, limits wheat production worldwide. Here, TaCPK7-D, encoding a subgroup III member of the calcium-dependent protein kinase (CPK) family, was identified from the sharp eyespot-resistant wheat line CI12633 through comparative transcriptomic analysis. Subsequently, the defence role of TaCPK7-D against R. cerealis infection was studied by the generation and characterization of TaCPK7-D-silenced and TaCPK7-D-overexpressing wheat plants. Rhizoctonia cerealis inoculation induced a higher transcriptional level of TaCPK7-D in the resistant wheat line CI12633 than in the susceptible cultivar Wenmai 6. The expression of TaCPK7-D was significantly induced after exogenous application of 1-aminocyclopropane-1-carboxylic acid (an ethylene biosynthesis precursor). The green fluorescent protein signal distribution assays indicated that TaCPK7-D localizes to the plasma membrane in both onion epidermal cells and wheat protoplasts. Following R. cerealis inoculation, TaCPK7-D-silenced wheat CI12633 plants displayed more severe sharp eyespot symptoms than control CI12633 plants. Four defence-associated genes (β-1,3-glucanase, chitinase 1, defensin and TaPIE1) and an ethylene biosynthesis key gene, ACO2, were significantly suppressed in the TaCPK7-D-silenced wheat plants compared with control plants. Conversely, TaCPK7-D-overexpressing wheat lines showed increased resistance to sharp eyespot compared with untransformed recipient wheat Yangmai 16. Furthermore, the transcriptional levels of these four defence-related genes and ACO2 gene were significantly elevated in TaCPK7-D-overexpressing plants compared with untransformed recipient wheat plants. These results suggest that TaCPK7-D positively regulates the wheat resistance response to R. cerealis infection through the modulation of the expression of these defence-associated genes, and that TaCPK7-D is a candidate to improve sharp eyespot resistance in wheat.

Keywords: CPK gene TaCPK7-D; overexpression; resistance; sharp eyespot; virus-induced gene silencing; wheat.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biosynthetic Pathways / genetics
  • Cell Membrane / metabolism
  • Chromosomes, Plant / metabolism
  • Disease Resistance*
  • Ethylenes
  • Gene Expression Regulation, Plant
  • Gene Silencing
  • Onions / cytology
  • Phylogeny
  • Plant Diseases / genetics
  • Plant Diseases / microbiology*
  • Plant Epidermis / cytology
  • Protein Kinases / metabolism*
  • Protein Transport
  • Rhizoctonia / physiology
  • Signal Transduction / genetics
  • Transcription, Genetic
  • Triticum / enzymology*
  • Triticum / genetics
  • Triticum / immunology
  • Triticum / microbiology*


  • Ethylenes
  • ethylene
  • Protein Kinases
  • calcium-dependent protein kinase