title: The wheat calcium-dependent protein kinase TaCPK7-D positively regulates host resistance to sharp eyespot disease.
abstract: 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.
authors.affiliation: The National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
authors.forename: Xuening
authors.initials: X
authors.lastname: Wei
authors.affiliation: The National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.|College of Agronomy, Northwest A&F University, Yangling, 712100, China.
authors.forename: Fangdi
authors.initials: F
authors.lastname: Shen
authors.affiliation: The National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
authors.forename: Yantao
authors.initials: Y
authors.lastname: Hong
authors.affiliation: The National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Rong
authors.affiliation: The National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
authors.forename: Lipu
authors.initials: L
authors.lastname: Du
authors.affiliation: The National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Liu
authors.affiliation: The National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
authors.forename: Huijun
authors.initials: H
authors.lastname: Xu
authors.affiliation: The National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.|College of Agronomy, Northwest A&F University, Yangling, 712100, China.
authors.forename: Lingjian
authors.initials: L
authors.lastname: Ma
authors.affiliation: The National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, China. zhangzengyan@caas.cn.
authors.forename: Zengyan
authors.initials: Z
authors.lastname: Zhang
mesh_terms: D053898:Biosynthetic Pathways / Q000235:genetics; D002462:Cell Membrane / Q000378:metabolism; D032461:Chromosomes, Plant / Q000378:metabolism; D060467:Disease Resistance; D005030:Ethylenes; D018506:Gene Expression Regulation, Plant; D020868:Gene Silencing; D019697:Onions / Q000166:cytology; D010802:Phylogeny; D010935:Plant Diseases / Q000235:genetics / Q000382:microbiology*; D019441:Plant Epidermis / Q000166:cytology; D011494:Protein Kinases / Q000378:metabolism*; D021381:Protein Transport; D012232:Rhizoctonia / Q000502:physiology; D015398:Signal Transduction / Q000235:genetics; D014158:Transcription, Genetic; D014908:Triticum / Q000201:enzymology* / Q000235:genetics / Q000276:immunology / Q000382:microbiology*; D017871:Calcium-Calmodulin-Dependent Protein Kinases
chemical_list: D005030:Ethylenes; D011494:Protein Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases; C036216:ethylene
keywords: CPK gene TaCPK7-D; overexpression; resistance; sharp eyespot; virus-induced gene silencing; wheat