title: Priming with a double-stranded DNA virus alters Brassica rapa seed architecture and facilitates a defense response.
abstract: BACKGROUND
  Abiotic and biotic stresses alter genome stability and physiology of plants. Under some stressful situations, a state of stress tolerance can be passed on to the offspring rendering them more suitable to stressful events than their parents. In plants, the exploration of transgenerational response has remained exclusive to model species, such as Arabidopsis thaliana. Here, we expand transgenerational research to include Brassica rapa, a close relative to economically important plant canola (Brassica napus), as it is exposed to the biotic stress of a double-stranded DNA virus Cauliflower mosaic virus (CaMV).
  
  
  RESULTS
  Parent plants exposed to a low dose of 50ng purified CaMV virions just prior to the bolting stage produced significantly larger seeds than mock inoculated and healthy treatments. The progeny from these large seeds displayed resistance to the pathogen stress applied in the parental generation. Differences in defense pathways involving fatty acids, and primary and secondary metabolites were detected by de novo transcriptome sequencing of CaMV challenged progeny exhibiting different levels of resistance.
  
  
  CONCLUSIONS
  Our study highlights biological and cellular processes that may be linked to the growth and yield of economically important B. rapa, in a transgenerational manner. Although much remains unknown as to the mechanisms behind transgenerational inheritance, our work shows a disease resistance response that persists for several weeks and is associated with an increase in seed size. Evidence suggests that a number of changes involved in the persistent stress adaption are reflected in the transcriptome. The results from this study demonstrate that treating B. rapa with dsDNA virus within a critical time frame and with a specified amount of infectious pathogen produces economically important agricultural plants with superior coping strategies for growing in unfavorable conditions.
authors.affiliation: University of Lethbridge, 4401 University Drive, Lethbridge, Alberta T1K 3M4, Canada; Agriculture and Agri-Food Canada, P.O. Box 3000, Lethbridge, Alberta T1J 4B1, Canada. Electronic address: melanie.kalischuk@lethbridgecollege.ca.
authors.forename: Melanie L
authors.initials: ML
authors.lastname: Kalischuk
authors.affiliation: University of Lethbridge, 4401 University Drive, Lethbridge, Alberta T1K 3M4, Canada. Electronic address: dan.johnson@uleth.ca.
authors.forename: Dan
authors.initials: D
authors.lastname: Johnson
authors.affiliation: Agriculture and Agri-Food Canada, P.O. Box 3000, Lethbridge, Alberta T1J 4B1, Canada. Electronic address: lawrence.kawchuk@agr.gc.ca.
authors.forename: Lawrence M
authors.initials: LM
authors.lastname: Kawchuk
mesh_terms: D029741:Brassica rapa / Q000033:anatomy & histology / Q000276:immunology / Q000378:metabolism* / Q000821:virology; D017796:Caulimovirus / Q000502:physiology*; D060467:Disease Resistance; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D054884:Host-Pathogen Interactions; D058977:Molecular Sequence Annotation; D010641:Phenotype; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D012639:Seeds / Q000033:anatomy & histology / Q000276:immunology / Q000378:metabolism* / Q000821:virology; D059467:Transcriptome
chemical_list: D010940:Plant Proteins
keywords: Biotic stress; Epigenetics; Pararetrovirus; Small RNAs; Transcriptome