Biomedical subjects

Reinhard Simon

Publications and source records attributed to Reinhard Simon.

3 recordsLinked to original sources

PubMed2006

Generation Challenge Programme (GCP): standards for crop data.

The Generation Challenge Programme (GCP) is an international research consortium striving to apply molecular biological advances to crop improvement for developing countries. Central to its activities is the creation of a next generation global crop information platform and network to share genetic resources, genomics, and crop improvement information. This system is being designed based on a comprehensive scientific domain object model and associated shared ontology. This model covers germplasm, genotype, phenotype, functional genomics, and geographical information data types needed in GCP research. This paper provides an overview of this modeling effort.

Crops, Agricultural↗

PubMed2002

Plant defense genes associated with quantitative resistance to potato late blight in Solanum phureja x dihaploid S. tuberosum hybrids.

Markers corresponding to 27 plant defense genes were tested for linkage disequilibrium with quantitative resistance to late blight in a diploid potato population that had been used for mapping quantitative trait loci (QTLs) for late blight resistance. Markers were detected by using (i) hybridization probes for plant defense genes, (ii) primer pairs amplifying conserved domains of resistance (R) genes, (iii) primers for defense genes and genes encoding transcriptional regulatory factors, and (iv) primers allowing amplification of sequences flanking plant defense genes by the ligation-mediated polymerase chain reaction. Markers were initially screened by using the most resistant and susceptible individuals of the population, and those markers showing different allele frequencies between the two groups were mapped. Among the 308 segregating bands detected, 24 loci (8%) corresponding to six defense gene families were associated with resistance at chi2 > or = 13, the threshold established using the permutation test at P = 0.05. Loci corresponding to genes related to the phenylpropanoid pathway (phenylalanine ammonium lyase [PAL], chalcone isomerase [CHI], and chalcone synthase [CHS]), loci related to WRKY regulatory genes, and other -defense genes (osmotin and a Phytophthora infestans-induced cytochrome P450) were significantly associated with quantitative disease resistance. A subset of markers was tested on the mapping population of 94 individuals. Ten defense-related markers were clustered at a QTL on chromosome III, and three defense-related markers were located at a broad QTL on chromosome XII. The association of candidate genes with QTLs is a step toward understanding the molecular basis of quantitative resistance to an important plant disease.

Acyltransferases↗

PubMed1990

Conjugal Transfer of Megaplasmid 2 between Rhizobium meliloti Strains in Alfalfa Nodules.

A DNA fragment containing the RP4 mob function, as well as the gentamicin and spectinomycin resistance genes, was inserted by gene replacement onto the megaplasmid 2 (pM2) of Rhizobium meliloti 0540 (Inf EPS), resulting in PG101 (Inf EPS). The self-transfer of pM2 and the mobilization of pM2 by plasmid RP4-4 were investigated during conjugation between PG101 and R. meliloti 2526 (Nod). In filter conjugations, pM2 was readily mobilized by RP4-4. In addition to this, the self-transfer of one megaplasmid (pM) was detected at a frequency of 3 x 10. Bacteria isolated from the nodules of alfalfa and coinoculated with strains PG101 and 2526 showed that pM2 was mobilized at a frequency of approximately 7 x 10. Bacterial cell numbers were too low in the nodules for detection of the self-transfer of pM2 to occur. No pM2 transfer was detected in the inoculum. A comparison of the transfer frequencies for the various conjugation conditions revealed that pM2 transfer occurred as frequently in the nodules as in filter conjugations. These results indicate that the nodule creates conditions for gene transfer that are comparable to optimal laboratory conditions.

Journal Article↗