Project description:Transcriptome analysis reveals the response mechanism of Frl-mediated resistance to Fusarium oxysporum f. sp. radicis-lycopersici (FORL) infection in tomato
Project description:In plant pathogenic fungi, conditionally dispensable (CD) chromosomes are often associated with virulence, but not viability. Such virulence-associated CD chromosomes carry genes encoding effectors and/or host-specific toxin biosynthesis enzymes, potentially important for determining host specificity. Fusarium oxysporum causes devastating diseases of more than 100 plant species. In particular, F. oxysporum f. sp. conglutinans (Focn) can infect Brassicaceae plants including Arabidopsis and cabbage. Here we show that Focn has multiple CD chromosomes involving in not only virulence but also vegetative growth, which is an atypical feature of known CD chromosomes. Among them, we identified specific CD chromosomes that are required for virulence to either Arabidopsis, cabbage, or both. We revealed that a pair of effectors encoded in one of the CD chromosomes is required for suppression of the Arabidopsis-specific phytoalexin-based immunity. The effector pair is highly conserved in F. oxysporum isolates capable of infecting Arabidopsis. This study provides insights into how host specificity of F. oxysporum is determined by a pair of effector genes on a CD chromosome.
Project description:Upon exposure to unfavorable environmental conditions, plants need to respond quickly to maintain their homeostasis. For instance, physiological, biochemical and transcriptional changes occur during plant-pathogen interaction. In the case of Vanilla planifolia Jacks., a worldwide economically important crop, it is susceptible to Fusarium oxysporum f. sp. vanillae. This pathogen causes root and stem rot in vanilla plants that lead to plant death. To investigate how vanilla plants, respond at the transcriptional level upon infection with F. oxysporum f. sp. vanillae, here we employed the RNA-Seq approach to analyze the dynamics of whole-transcriptome changes during two-time frames of the infection. Analysis of global gene expression profiles indicated that the major transcriptional change occurred at 2 dpi, in comparison to 10 dpi. Whereas 3420 genes were found with a differential expression at 2 dpi, only 839 were identified at 10 dpi. The analysis of the transcriptional profile at 2 dpi suggests that, among other responses, vanilla plants prepare to counter the infection by gathering a pool of translational regulation-related transcripts. The screening of transcriptional changes of V. planifolia Jacks upon infection by F. oxysporum f. sp. vanillae provides insights into the plant molecular response, particularly the upregulation of ribosomal proteins at early stages. Thus, we propose that the plant-pathogen interaction between V. planifolia Jacks and F. oxysporum f. sp. vanillae causes a transcriptional reprogramming coupled with a translational regulation. Altogether, this study provides the identification of molecular players that could help to fight the most damaging disease of vanilla.