Project description:The host range of parasites is an important factor in assessing the dynamics of disease epidemics. The evolution of pathogens to accommodate new hosts may lead to host range expansion, a process the molecular bases of which are largely enigmatic. The fungus Sclerotinia sclerotiorum parasitizes more than 400 plant species from diverse eudicot families while its close relative, S. trifoliorum, is restricted to plants from the Fabaceae family. We analyzed S. sclerotiorum global transcriptome reprogramming on hosts from six botanical families and reveal a flexible, host-specific transcriptional program driven by core and host-response co-expression (SPREx) gene clusters. We generated a chromosome-level genome assembly for S. trifoliorum and found near-complete gene space conservation in broad and narrow host range Sclerotinia species. However, S. trifoliorum showed increased sensitivity to the Brassicaceae defense compound camalexin. Inter-specific transcriptome analyses revealed a lack of transcriptional response to camalexin in S. trifoliorum and provide evidence that cis-regulatory variation associates with the genetic accommodation of Brassicaceae in the Sclerotinia host range. Our work demonstrates adaptive plasticity of a broad host range pathogen with specific responses to different host plants and demonstrates the co-existence of signatures for generalist and polyspecialist life styles in the genome of a plant pathogen. We reason that this mechanism enables the emergence of new disease with no or limited gene flow between strains and species, and could underlie the emergence of new epidemics originating from wild plants in agricultural settings.
Project description:This SuperSeries is composed of the following subset Series: GSE13254: Sclerotinia infected vs Mock infected controls in B. napus (Westar) GSE13256: Zhong You 821 Sclerotinia infected vs Mock infected controls in B. napus (Zhong You 821) The fungal pathogen Sclerotinia sclerotiorum infects a broad range of dicotyledonous plant species and is the causative agent of stem rot in Brassica napus. To elucidate the mechanisms underlying the defense response, we studied the patterns of gene expression in a partially resistant variety of ZhongYou 821 (ZY821) and a susceptible line from Westar over five time points, 6, 12, 24, 48, and 72 hours post-inoculation (hpi) using a B. napus oligonucleotide microarray. For each cultivar, a two-dye experiment was run comparing infected to mock-infected stem tissue. For each time point, 6 microarray slides were done (3 biological replicates, with a dye swap for each biological replicate). Refer to individual Series
Project description:This SuperSeries is composed of the following subset Series: GSE15337: Gene expression profiling soybean stem tissue early response to Sclerotinia sclerotiorum 1 GSE15338: Gene expression profiling soybean stem tissue early response to Sclerotinia sclerotiorum 3 GSE15339: Gene expression profiling soybean stem tissue early response to Sclerotinia sclerotiorum 4 GSE15340: Gene expression profiling soybean stem tissue early response to Sclerotinia sclerotiorum 2 Refer to individual Series
