Project description:Total RNA extracted from Phytophthora sojae (strain P6497) and infected soybean hypocotyls (cultivar Harosoy) provided template for synthesis of cDNA probes used in the microarray hybridizations. Infected plant hypocotyls were sampled 6 h, 12 h, 24 h, and 48 h after inoculation. Mycelia were grown on synthetic media (H&S) or vegetable juice media (V8). Zoospores were sampled at 0 h, 2 h and 6 h after inducing encystment and germination by agitation. We used microarrays to characterize gene expression patterns in the root rot pathogen Phytophthora sojae and its host Glycine max. Keywords: infection time course, zoospore germination time course, media formulation response Overall design: 28 samples from 9 treatments; 2 to 5 biological replicates per treatment.
Project description:Total RNA extracted from Phytophthora sojae (strain P6497) and infected soybean hypocotyls (cultivar Harosoy) provided template for synthesis of cDNA probes used in the microarray hybridizations. Infected plant hypocotyls were sampled 6 h, 12 h, 24 h, and 48 h after inoculation. Mycelia were grown on synthetic media (H&S) or vegetable juice media (V8). Zoospores were sampled at 0 h, 2 h and 6 h after inducing encystment and germination by agitation. We used microarrays to characterize gene expression patterns in the root rot pathogen Phytophthora sojae and its host Glycine max. Keywords: infection time course, zoospore germination time course, media formulation response 28 samples from 9 treatments; 2 to 5 biological replicates per treatment.
Project description:Soybean is one of the most important economic and oil crops across the world. Phytophthora root rot (PRR), caused by <i>Phytophthora sojae</i> (<i>P. sojae</i>), is a major disease in most soybean-growing regions worldwide. Here, we investigated metabolic changes in hypocotyls of two soybean lines, Nannong 10-1 (resistant line, R) and 06-070583 (susceptible line, S), at two time points (12 and 36 hpi) after <i>P. sojae</i> infection and metabolic differences between the R line and the S line. In total, 90 differentially accumulated metabolites (DAMs) were identified after <i>P. sojae</i> infection; the levels of 50 metabolites differed between the R line and the S line. There are 28 DAMs that not only differentially accumulated between the R line and the S line but also differentially accumulated after <i>P. sojae</i> infection. Based on the changes of these DAMs in response to <i>P. sojae</i> infection in different lines and at different timepoints, and the differences in the contents of these DAMs between the R line and the S line, we speculated that DAMs, including sugars (monosaccharides and oligosaccharides), organic acids (oxalic acid, cumic acid), amino acid derivatives, and other secondary metabolites (mannitol, octanal, hypoxanthine, and daidzein etc.) may participate in the metabolic-level defense response of soybean to <i>P. sojae</i>. In this study, an integrated pathway-level analysis of transcriptomics (obtained by RNA-Seq) and metabolomics data illustrated the poor connections and interdependencies between the metabolic and transcriptional responses of soybean to <i>P. sojae</i> infection. This work emphasizes the value of metabolomic studies of plant-pathogen interactions and paves the way for future research of critical metabolic determinants of the soybean-<i>P. sojae</i> interaction.
Project description:Examination of soybean hypocotyls, G. max cv. Harosoy (Rps7), at 3, 6, 12, 24 and 48 hours after inoculation with P. sojae, race 2, isolate P6497 Patterns of Gene Expression Upon Infection of Soybean Plants by Phytophthora sojae. P. Moy, D. Qutob, B. P. Chapman, I. Atkinson, and M. Gijzen. Pages 1051-1062. Publication no. M-2004-0728-01R. Molecular Plant-Microbe Interactions, October 2004, Volume 17, Number 10. Keywords: time-course
Project description:Hypocotyls of soybean (Glycine max) seedlings of cultivar Williams were inoculated with mycelia of the oomycete pathogen Phytophthora sojae grown in liquid V8 medium or the hypocotyls were mock inoculated. After 12 hours, the sites of inoculation were excised from the hypocotyls and frozen for RNA extraction. Phytophthora sojae mycelia used for inoculation was saved for RNA extraction also Overall design: Four replicate experiments were conducted. Each replicate consisted of 30 P. sojae-inoculated or mock-inoculated hypocotyls, as well as a sample of the P. sojae mycelia used for the 30 inoculations
Project description:Phytophthora ramorum and Phytophthora sojae are destructive plant pathogens. P. sojae has a narrow host range, whereas P. ramorum has a wide host range. A global proteomics comparison of the vegetative (mycelium) and infective (germinating cyst) life stages of P. sojae and P. ramorum was conducted to identify candidate proteins involved in host range, early infection, and vegetative growth. Sixty-two candidates for early infection, 26 candidates for vegetative growth, and numerous proteins that may be involved in defining host specificity were identified. In addition, common life stage proteomic trends between the organisms were observed. In mycelia, proteins involved in transport and metabolism of amino acids, carbohydrates, and other small molecules were up-regulated. In the germinating cysts, up-regulated proteins associated with lipid transport and metabolism, cytoskeleton, and protein synthesis were observed. It appears that the germinating cyst catabolizes lipid reserves through the beta-oxidation pathway to drive the extensive protein synthesis necessary to produce the germ tube and initiate infection. Once inside the host, the pathogen switches to vegetative growth in which energy is derived from glycolysis and utilized for synthesis of amino acids and other molecules that assist survival in the plant tissue.
Project description:Phytophthora sojae causes soybean root and stem rot, resulting in an annual loss of 1-2 billion US dollars in soybean production worldwide. A proteomic technique was used to determine the effects on soybean hypocotyls of infection with P. sojae.In the present study, 46 differentially expressed proteins were identified in soybean hypocotyls infected with P. sojae, using two-dimensional electrophoresis and matrix-assisted laser desorption/ionization tandem time of flight (MALDI-TOF/TOF). The expression levels of 26 proteins were significantly affected at various time points in the tolerant soybean line, Yudou25, (12 up-regulated and 14 down-regulated). In contrast, in the sensitive soybean line, NG6255, only 20 proteins were significantly affected (11 up-regulated and 9 down-regulated). Among these proteins, 26% were related to energy regulation, 15% to protein destination and storage, 11% to defense against disease, 11% to metabolism, 9% to protein synthesis, 4% to secondary metabolism, and 24% were of unknown function.Our study provides important information on the use of proteomic methods for studying protein regulation during plant-oomycete interactions.
Project description:The transcriptome of the oomycete plant pathogen Phytophthora sojae was profiled at 10 different developmental and infection stages based on a 3'-tag digital gene expression (DGE) protocol. More than 90 million clean sequence tags were generated and compared to the P. sojae genome and its 19,027 predicted genes. A total of 14,969 genes were detected, of which 10,044 were deemed reliable because they mapped to unambiguous tags. A comparison of the whole-library genes expression patterns suggested four groups: 1) mycelia and zoosporangia (MY and SP); 2) zoospores and cysts (ZO and CY); 3) germinating cysts (GC); 4) five infection site libraries (IF1.5 to IF24h). The libraries from the different groups showed major transitional shifts in gene expression. From the ten libraries, 722 gene expression pattern clusters were obtained and the top 16 ones, containing more than half of the genes, comprised enriched genes with different functions including protein localization, triphosphate metabolism, signaling process, and non-coding RNA metabolism. An evaluation of the average expression level of 30 pathogenesis related gene families revealed that most were infection induced, but with diverse expression patterns and levels. A web-based server named the Phytophthora Transcriptional Database (PTD) has been established. The five axenically grown stages were mycelia (MY), zoosporangia (SP), zoospores (ZO), cysts (CY), and germinating cysts (GC). The five infection stages, 1.5, 3, 6, 12 and 24 h after inoculation onto susceptible soybean leaf tissues (IF1.5h to IF24h).
Project description:The genus Phytophthora consists of many notorious pathogens of crops and forestry trees. At present, battling Phytophthora diseases is challenging due to a lack of understanding of their pathogenesis. We investigated the role of small RNAs in regulating soybean defense in response to infection by Phytophthora sojae, the second most destructive pathogen of soybean. Small RNAs, including microRNAs (miRNAs) and small interfering RNAs (siRNAs), are universal regulators that repress target gene expression in eukaryotes. We identified known and novel small RNAs that differentially accumulated during P. sojae infection in soybean roots. Among them, miR393 and miR166 were induced by heat-inactivated P. sojae hyphae, indicating that they may be involved in soybean basal defense. Indeed, knocking down the level of mature miR393 led to enhanced susceptibility of soybean to P. sojae; furthermore, the expression of isoflavonoid biosynthetic genes was drastically reduced in miR393 knockdown roots. These data suggest that miR393 promotes soybean defense against P. sojae. In addition to miRNAs, P. sojae infection also resulted in increased accumulation of phased siRNAs (phasiRNAs) that are predominantly generated from canonical resistance genes encoding nucleotide binding-leucine rich repeat proteins and genes encoding pentatricopeptide repeat-containing proteins. This work identifies specific miRNAs and phasiRNAs that regulate defense-associated genes in soybean during Phytophthora infection.