Project description:We created stable transgenic soybean plants that express and secrete two different PI3P-binding proteins, GmPH1 and VAM7, in an effort to interfere with effector delivery and confer resistance. Soybean plants expressing the two PI3P-binding proteins exhibited reduced infection by the oomycete pathogen Phytophthora sojae compared to control lines. Measurements of nodulation by nitrogen-fixing mutualistic bacterium Bradyrhizobium japonicum, which does not produce PI3P, revealed that the two lines with the highest levels of GmPH1 transcripts exhibited reductions in nodulation and in benefits from nodulation. Transcriptome and plant hormone measurements were made of soybean lines with the highest transcript levels of GmPH1 and VAM7, as well as controls, following P. sojae- or mock-inoculation. The results revealed increased levels of infection-associated transcripts in the transgenic lines, compared to controls, even prior to P. sojae infection, suggesting that the plants were primed for increased defense.
Project description:Identify plant and pathogen genes differentially expressed during P. sojae infection of soybean cultivars differing in quantitative resistance, by using Affymetrix Soybean Genome Array analysis. Experiment Overall Design: RNA samples from mock-inoculated soybean tissue contain 2%-16% spike-in RNA from Phytophthora sojae mycelium grown in liquid sucrose-salts medium. Experiment Overall Design: 4 Experimental Replicates x 8 cultivars x 2 Treatments (inoculated or mock) x 2 Timepoints (72hr or 120hr) = 128 samples in total
Project description:To identify soybean genes and QTLs associated with quantitative resistance to infection by the oomycete pathogen Phytophthora sojae, we conducted a very large-scale microarray experiment using 2522 Affymetrix GeneChips. The experiment involved assaying a total of 298 soybean recombinant inbred lines together with internal checks.
Project description:Identify plant and pathogen genes differentially expressed during P. sojae infection of soybean cultivars differing in quantitative resistance, by using Affymetrix Soybean Genome Array analysis. Keywords: genotypic variation on quantitative resistance
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
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:Phytophthora root and stem rot caused by the oomycete pathogen Phytophthora sojae, is one of the most destructive diseases of soybean. Deploying soybean cultivars carrying race-specific resistance conferred by Rps genes is the most practicalapproach to managing this disease. Previously, two Rps genes, RpsUN1 and RpsUN2 conferring broad spectra of resistance to P. sojae isolates, were identified in a landrace PI 567139B and mapped to a 6.5-cM region on chromosome 3 and a 3.0-cM region on chromosome 16, corresponding to 840 kb and 600 kb of sequences, respectively,of the soybean reference genome. By analyzing ten and nine recombinants defined by genotypic and phenotypic screening of the 826 F2:3 families derived from two reciprocal crosses between the two parental lines of the mapping populations, RpsUN1 and RpsUN2 were further narrowed to a 151-kb region that harbors five genes including three NBS-LRR genes, and a 36-kb region that contains four genes including five NBS-LRR genes, respectively, according to the reference genome. Analysis of expressional changes of these nine genes before and after inoculation with the pathogen suggest that the counterparts of Glyma.03g034600 in the RpsUN1 region and the counterparts of Glyma.16g215200 and Glyma.16g214900 in the RpsUN2 region of PI 567139B may be associated with the resistance to P. sojae. It is also suggested that unequal recombination between different NBS-LRR genes in the mapped regions may have occurred, resulting in the formation of two recombinants with inconsistent genotypes and phenotypes detected by molecular markers within the fine-mapped regions. The haplotypes of genomic regions surrounding RpsUN1 and RpsUN2 in the entire soybean germplasm deposited in the US soybean germplasm collection were analyzed towards a better understanding of the origins of these two novel sources of resistance and screening of effective markers for marker-assisted selectionof these two resistance genes for soybean breeding.
