Project description:The expression of genes in P. infestans isolates 06_3928A and NL07434 was monitored from 2 to 4 days time course of a potato infection. Genes encoding known and putative effector proteins were found induced at two and/or three days post-inoculation. We used a custom chip GPL8093 from Roche Nimblegen’s proprietary Maskless Array Synthesis (MAS) technology uses digital light processing and rapid, high-yield photochemistry to synthesize long oligo, high-density DNA microarrays with extreme flexibility. Each GPL8093 chip measures the expression level of 18155 genes from Phytophthora infestans with 60-mer probe pairs (PM/MM) per gene. Total RNA samples recovered from mycelia in two medias (rye sucrose agar and V8 agar) and infected potato leaves from a time couse infection (2, 3 and 4 days post incoulation). Experiments included two biological repllicates from each sample. We carried out total RNA extractions (mycelia and potato infected material) for two P. infestans isolates 06_3928A and NL07434. cDNA synthesis was performed Nimblegen.
Project description:The expression of genes in P. infestans was monitored over a five day time course of a potato infection. Genes encoding known and putative effector proteins were found induced at two days post-inoculation with expression decaying over the five day time course.
Project description:The expression of genes in P. infestans isolates 06_3928A and NL07434 was monitored from 2 to 4 days time course of a potato infection. Genes encoding known and putative effector proteins were found induced at two and/or three days post-inoculation.
Project description:The late blight pathogen, Phytophthora infestans has a broad host range within the Solanaceae family, including yellow potato (Solanum phureja). The disease caused by P. infestans in S. phureja is poorly understood and is a major concern in Colombia. Expressed Sequence Tag (EST) libraries obtained from a normalized library constructed from healthy plant tissue revealed high levels of sequence similarity between S. phureja and S. tuberosum. Then, utilizing Serial Analysis of Gene Expression and high-throughput sequencing (SAGE-Solexa), we characterized yellow potato gene expression during infection by P. infestans. Four-week-old yellow potato plants were inoculated with P. infestans and were collected at 12 and 72 hours post inoculation for RNA extraction. We detected differentially expressed genes by comparing inoculated to non-inoculated and resistant to susceptible plants. The discovery and characterization of the proteins mediating this host–pathogen interaction enable the understanding of the pathosystem and is the key for developing resistant plants. Keywords: SAGE-Solexa, inoculation response, transcript profiling, Solanum phureja, Phytophthora infestans
Project description:Phytophthora infestans is most notorious oomycete causing a devastating disease on tomato called late blight. The molecular mechanisms involved in host-parasite interaction is still unexplored well. Investigation of changes in gene expression profile after pathogen infection to find out the mechanisms involved in infection process Second full expanded leaves from both healthy tomato plants (non-inoculated) and diseased tomato plants inoculated with Phytophthora infestans inoculum were used to extract total RNA for microarry analysis 12 hours post inoculation time.
Project description:The late blight pathogen, Phytophthora infestans has a broad host range within the Solanaceae family, including yellow potato (Solanum phureja). The disease caused by P. infestans in S. phureja is poorly understood and is a major concern in Colombia. Expressed Sequence Tag (EST) libraries obtained from a normalized library constructed from healthy plant tissue revealed high levels of sequence similarity between S. phureja and S. tuberosum. Then, utilizing Serial Analysis of Gene Expression and high-throughput sequencing (SAGE-Solexa), we characterized yellow potato gene expression during infection by P. infestans. Four-week-old yellow potato plants were inoculated with P. infestans and were collected at 12 and 72 hours post inoculation for RNA extraction. We detected differentially expressed genes by comparing inoculated to non-inoculated and resistant to susceptible plants. The discovery and characterization of the proteins mediating this host–pathogen interaction enable the understanding of the pathosystem and is the key for developing resistant plants. Keywords: SAGE-Solexa, inoculation response, transcript profiling, Solanum phureja, Phytophthora infestans Four-week-old yellow potato (Solanum phureja) plants were inoculated with Phytophthora infestans and were collected and flash frozen in liquid nitrogen at 12 and 72 hours post inoculation, as well as mock inoculated, for RNA extraction. 2 yellow potato cultivars (resistant and susceptible) were used for each experiment. Mock inoculated plants were collected in each replicate. RNA obtained from each of the three biological replicates was pooled to obtain a single RNA sample for each timepoint X cultivar combination. A total of 6 different SAGE libraries were thus obtained. For all libraries, Illumina sequencing was performed at Canada´s Michael Smith Genome Sciences Centre.
Project description:Phytophthora spp. encode large sets of effector proteins and distinct populations of small RNAs (sRNAs). Reports suggest that pathogen-derived sRNAs can modulate the expression of plant defense genes. The experiments reported here were designed to shed light on impact of sRNAs in the potato-P. infestans interaction. We used the Argonaute or Ago1 from P. infestans tagged with GFP transformed into the 88069 strain to infect potato cv. Bintje plants. Collected leaf materials were used in co-immunoprecipitation experiments together with P. infestans harboring GFP (control GFP) and P. infestans mycelia grown on media (control mycelia). These three materials were sequenced at a Ion Proton platform. The reads length of 8-38 nt were adaptor-trimmed and mapped to the P. infestans genome and the Solanom tuberosum genome v4.04. Both P. infestans-associated and potato derived sRNAs were identified.
Project description:Phytophthora infestans, the causal agent of potato late blight, is a devastating plant disease that was responsible for the Irish potato famine and continues to threaten global food security. While the P. infestans genome is an excellent resource for studying the aggressiveness of this pandemic pathogen, its epigenome remains poorly understood. In this study, utilizing liquid chromatography-tandem mass spectrometry (LC-MS/MS), we identified post-translational modifications (PTMs) at the P. infestans core histone H3. The PTMs include prevalent modifications in eukaryotes, as well as some novel marks, such as H3K53me2 and H3K122me3. We focused on trimethylations of H3K4, H3K9, H3K27, and H3K36, and profiled the P. infestans epigenome using native chromatin immunoprecipitation followed by sequencing (N-ChIP-seq). In parallel, we mapped P. infestans chromatin accessibility using the assay for transposase-accessible chromatin with high-throughput sequencing (ATAC-seq). We found that adaptive genomic compartments display significantly higher levels of H3K9me3 and H3K27me3 and are generally found in condensed chromatin. Interestingly, highly accessible regions with ATAC-seq peaks are also found in this compartment. We observed that genes encoding virulence factors, such as effectors, are enriched in open chromatin regions with few histone modifications. Based on N-ChIP-seq at 3 days post-incubation, we revealed the PTM dynamics in secretome genes from the mycelium to the infection stage. Using a combination of genomic, epigenomic, and transcriptomic strategies, our study illustrates the epigenetic states and changes in P. infestans, helping to elucidate genomic functions and regulation in this pathogen.
Project description:Late blight caused by Phytophthora infestans seriously threatens world’s potato production. Understanding the responsive mechanism of potato to P. infestans infection and exploring key regulators would be advantageous for improving the late blight resistance. Here, we assess the late blight resistance of various potato cultivars from Liangshan Yi Autonomous Prefecture and identified Chuan Liang Shu 10 (CLS) with strong resistant, while Bu Wu Yu (BWY) is highly susceptible. Comparative transcriptomics between these two cultivars upon P. infestans inoculation reveal that CLS activates defense pathways rapidly, while BWY prioritizes energy towards growth and development pathways, resulting in distinct late blight resistances. Specifically, the resistance of CLS might be contributed by enhanced oxidation-reduction process and SA signaling. Clustering analysis of the expression patterns for transcription factors (TFs) demonstrates that the WRKY family members play important roles in late blight resistance of CLS, among which StWRKY26 is identified as a positive regulator of late blight resistance. Silencing of StWRKY26 in CLS significantly compromise its intrinsic resistance to P. infestans. Our study enriches the knowledge of transcriptional responses of potato under P. infestans infection and provide candidate genes for breeding potato cultivars with strong late blight resistance.