A global study of transcriptome dynamics in canola (Brassica napus L.) responsive to Sclerotinia sclerotiorum infection using RNA-Seq.
The necrotrophic phytopathogen, Sclerotinia sclerotiorum, causes Sclerotinia stem rot, which is a serious constraint to canola (Brassica napus L.) production worldwide. To understand the detailed molecular mechanisms underlying host response to Sclerotinia infection, we analyzed the transcript level changes in canola post-infection with S. sclerotiorum in a time course of a compatible interaction using strand specific whole transcriptome sequencing. Following infection, 161 and 52 genes (P≤0.001) were induced while 24 and 23 genes were repressed at 24h post-inoculation (hpi) and 48hpi, respectively. This suggests that, a gradual increase in host cell lyses and increase virulence of the pathogen led to the expression of only a fewer host specific genes at the later stage of infection. We observed rapid induction of key pathogen responsive genes, including glucanases, chitinases, peroxidases and WRKY Transcription factors (TFs) within 24hpi, indicating early detection of the pathogen by the host. Only 16 genes were significantly induced at both the time points suggesting a coordinated suppression of host responses by the pathogen. In addition to genes involved in plant-pathogen interactions, many novel disease responsive genes, including various TF sand those associated with jasmonate (JA) and ethylene (ET) signalling were identified. This suggests that canola adopts multiple strategies in mediating plant responses to the pathogen attack. Quantitative real time PCR (qRT-PCR) validation of a selected set of genes demonstrated a similar trend as observed by RNA-Seq analysis and highlighted the potential involvement of these genes by the host to defend itself from pathogen attack. Overall, this work presents an in-depth analysis of the interaction between host susceptibility and pathogen virulence in the agriculturally important B. napus-S. sclerotiorum pathosystem.
Department of Agricultural Food and Nutritional Science, University of Alberta, Edmonton, Alberta T6G 2P5, Canada; Centre of Biotechnology, Siksha O Anusandhan University, Bhubaneswar 751003, India.
Raj Kumar
RK
Joshi
Department of Agricultural Food and Nutritional Science, University of Alberta, Edmonton, Alberta T6G 2P5, Canada.
Swati
S
Megha
Department of Agricultural Food and Nutritional Science, University of Alberta, Edmonton, Alberta T6G 2P5, Canada.
Muhammad Hafizur
MH
Rahman
Department of Agricultural Food and Nutritional Science, University of Alberta, Edmonton, Alberta T6G 2P5, Canada.
Urmila
U
Basu
Department of Agricultural Food and Nutritional Science, University of Alberta, Edmonton, Alberta T6G 2P5, Canada. Electronic address: nat@ualberta.ca.
Nat N V
NN
Kav
D001203:Ascomycota / Q000472:pathogenicity* / Q000502:physiology; D029688:Brassica napus / Q000235:genetics* / Q000276:immunology / Q000382:microbiology; D003517:Cyclopentanes / Q000378:metabolism; D005030:Ethylenes / Q000378:metabolism; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D063990:Gene Ontology; D054884:Host-Pathogen Interactions; D058977:Molecular Sequence Annotation; D054883:Oxylipins / Q000378:metabolism; D010935:Plant Diseases / Q000235:genetics* / Q000276:immunology / Q000382:microbiology; D057865:Plant Immunity / Q000235:genetics*; D018515:Plant Leaves / Q000235:genetics / Q000276:immunology / Q000382:microbiology; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D017423:Sequence Analysis, RNA; D015398:Signal Transduction; D014157:Transcription Factors / Q000235:genetics; D059467:Transcriptome
D003517:Cyclopentanes; D005030:Ethylenes; D054883:Oxylipins; D010940:Plant Proteins; D014157:Transcription Factors; C011006:jasmonic acid; C036216:ethylene
Canola; Necrotroph; Pathogenesis; Stem rot; Stranded-RNA-Seq; Transcriptomics