Arabidopsis Defense against Botrytis cinerea: Chronology and Regulation Deciphered by High-Resolution Temporal Transcriptomic Analysis    

Abstract

Transcriptional reprogramming forms a major part of a plant's response to pathogen infection. Many individual components and pathways operating during plant defense have been identified, but our knowledge of how these different components interact is still rudimentary. We generated a high-resolution time series of gene expression profiles from a single Arabidopsis thaliana leaf during infection by the necrotrophic fungal pathogen Botrytis cinerea. Approximately one-third of the Arabidopsis genome is differentially expressed during the first 48 h after infection, with the majority of changes in gene expression occurring before significant lesion development. We used computational tools to obtain a detailed chronology of the defense response against B. cinerea, highlighting the times at which signaling and metabolic processes change, and identify transcription factor families operating at different times after infection. Motif enrichment and network inference predicted regulatory interactions, and testing of one such prediction identified a role for TGA3 in defense against necrotrophic pathogens. These data provide an unprecedented level of detail about transcriptional changes during a defense response and are suited to systems biology analyses to generate predictive models of the gene regulatory networks mediating the Arabidopsis response to B. cinerea.

Arabidopsis MYC Transcription Factors Are the Target of Hormonal Salicylic Acid/Jasmonic Acid Cross Talk in Response to Pieris brassicae Egg Extract

“…Since woundactivation of VSP2 was strongly diminished in wrky75-25 and maintained after egg extract treatment in 35S: WRKY75, our results are consistent with a positive role of WRKY75 in the control of the JA-regulated genes independently of MYC2. WRKY75 was previously shown to play a role in plant defense against biotrophs and necrotrophs (Encinas- Villarejo et al, 2009;Windram et al, 2012;Chen et al, 2013). Noteworthy, WRKY75 overexpression was accompanied by elevated expression of JA-responsive genes, including PDF1.2, VSP1, and LOX2, and enhanced resistance against the necrotroph Sclerotinia sclerotiorum .…”

Expansive Phenotypic Landscape of Botrytis cinerea Shows Differential Contribution of Genetic Diversity and Plasticity

“…However, the in planta virulence of the pathogen is driven by an interaction of the genetics between both the pathogen and plant. We used digital imaging to measure the spatial characteristics of active lesions at 72 h postinoculation (hpi) in the Arabidopsis thaliana ecotype Col-0 and five of its single-gene mutants that have wellcharacterized deficiencies in pathogen defense, including pad3 (camalexin deficient mutant) (Zhou et al 1999), coi1 (jasmonate receptor) (Xie et al 1998), npr1 (salicylate receptor) (Cao et al 1997), tga3, and anac055 (transcription factors involved with response to B. cinerea) (Windram et al 2012). The use of these mutants allows us to survey how genetic shifts in the plant host will influence the pathogen as a model for shifts in host range.…”

The novel elicitor AsES triggers a defense response against Botrytis cinerea in Arabidopsis thaliana

“…A previous report demonstrated that the expression of approximately onethird of the A. thaliana transcriptome changes during the first 48 hpi with B. cinerea [32]. Thus, we focused on this window.…”