Origin and rearrangement of ribosomal DNA repeats in natural allotetraploid Nicotiana tabacum are described. Comparative sequence analysis of the intergenic spacer (IGS) regions of Nicotiana tomentosiformis (the paternal diploid progenitor) and Nicotiana sylvestris (the maternal diploid progenitor) showed species-specific molecular features. These markers allowed us to trace the molecular evolu...

* Correspondence: [email protected]

RNA editing in plant organelles is mediated by site-specific, nuclear-encoded factors. Previous data suggested that the maintenance of these factors depends on the presence of their rapidly evolving cognate sites. The surprising ability of allotetraploid Nicotiana tabacum (tobacco) to edit a foreign site in the chloroplast ndhA messenger RNA was thought to be inherited from its diploid male anc...

Gesellschaft für Biotechnologische Forschung, Mascheroder Weg, D-3300 Braunschweig-Stöckheim, Bundesrepublik Deutschland Z. Naturforsch. 42c, 69—72 (1987); received August 21/September 22, 1986 Agrobacterium rhizogenes, Alkaloids, Nicotine, Cytisine, Nicotiana, Spartium The growth of root hairs from stems of Nicotiana tabacum and Spartium junceum was induced by Agrobacterium rhizogenes. Stem ro...

Using dual cultures of arbuscular mycorrhizal (AM) fungi and Medicago truncatula separated by a physical barrier, we demonstrate that hyphae from germinating spores produce a diffusible factor that is perceived by roots in the absence of direct physical contact. This AM factor elicits expression of the Nod factor-inducible gene MtENOD11, visualized using a pMtENOD11-gusA reporter. Transgene ind...

Two PCR primer pairs were designed to amplify rRNA genes (rDNA) from all four major phyla of fungi: Ascomycota, Basidiomycota, Chytridomycota, and Zygomycota. PCRs performed with these primers showed that both pairs amplify DNA from organisms representing the major taxonomic groups of fungi but not from nonfungal sources. To test the ability of the primers to amplify fungal rDNA from environmen...

For Nicotiana, with 75 naturally occurring species (40 diploids and 35 allopolyploids), we produced 4656bp of plastid DNA sequence for 87 accessions and various outgroups. The loci sequenced were trnL intron and trnL-F spacer, trnS-G spacer and two genes, ndhF and matK. Parsimony and Bayesian analyses yielded identical relationships for the diploids, and these are consistent with other data, pr...

Phytophthora species are plant pathogens responsible for many notable biological invasions in agricultural, forests, and natural ecosystems. Detection monitoring invasive introductions of spp. is time resource intensive. Development citizen science detection programs can aid these efforts focused on reducing Phythophthora impacts. There multiple methods detecting suitable approaches such as, le...