Oxidation reactions are required to produce atranorin from acetate by alginate-immobilized cells of Cladonia verticillaris.

Atranorin, a p-depside of the b-orcinol series, is produced by several Cladonia species. Immobilized cells of Cladonia verticillaris in calcium alginate are able to produce atranorin when they are supplied with 1.0 mM acetate as a precursor. Production of the depside is enhanced by adding an oxidant agent (NAD+ or FMN) to the incubation media and its secretion to these media is facilitated by permeabilizing the immobilized cells with 2 % iso-propanol

Translational recoding as a feedback controller : systems approaches reveal polyamine-specific effects on the antizyme ribosomal frameshift

Peer reviewedPublisher PD

Acquisition and Evolution of Plant Pathogenesis–Associated Gene Clusters and Candidate Determinants of Tissue-Specificity in Xanthomonas

is a large genus of plant-associated and plant-pathogenic bacteria. Collectively, members cause diseases on over 392 plant species. Individually, they exhibit marked host- and tissue-specificity. The determinants of this specificity are unknown. lineage. genome and indicate that differentiation with respect to host- and tissue-specificity involved not major modifications or wholesale exchange of clusters, but subtle changes in a small number of genes or in non-coding sequences, and/or differences outside the clusters, potentially among regulatory targets or secretory substrates

Production of phenolics by immobilized cells of the lichen Pseudevernia furfuracea: the role of epiphytic bacteria

Immobilized lichen cells from the thalli of the lichen Pseudevernia furfuracea, supplied with acetate as the only source of carbon, continuously produced phenolic substances, atranorin and physodic acid, over 23 days. Epiphytic bacteria associated with the lichen thallus grew actively, probably using both acetate and reduced compounds supplied by lichen cells, since their active growth was avoided by including 10 μM 3,3′-dichlorophenyl-1,1′ dimethylurea in the bath solution. Penicillin largely impeded the growth of epiphytic bacteria and decreased phenolic production, which was recovered only at the end of the experimental period, just when the bacteria started a slow, but active growth. We suggest the cooperation of epiphytic bacteria in the biosynthesis of both atranotrin and physodic acid

Microscopic Analyses of Latent and Visible Monilinia fructicola Infections in Nectarines.

Little is known about the histologic features of a latent Monilinia fructicola infection and brown rot in infected fruit. This report informs on the results of an investigation whose aim was to analyze the microanatomy of nectarines with a latent and visible M. fructicola infection. Mature nectarines were inoculated with an M. fructicola isolate and incubated at 25°C for 0, 24, 48, 72, or 96 hours in the dark. For investigating the latent infection process, the inoculated nectarines were first incubated at 25°C for 24 hours in the dark and then incubated at 4°C for 72, 144, 216, and 288 hours in the dark. At the end of the incubation, samples of nectarine tissue were excised from the inoculation points and prepared for light and transmission electron microscopic examinations. No signs of disease were seen on the surface of nectarines with a latent infection over the 288-hour incubation period. When the tissue samples were microscopically examined, M. fructicola colonized the stomata and this stomatal colonization progressively increased over time and was associated with gradual collapse of the epidermal cells and colonization of the subepidermis. In nectarines with visible brown rot, the disease usually appeared after 24 hours on the surface and in the uppermost layers of epidermal cells, which began to collapse after 48 hours. Subsequently, the diseased tissues of the nectarines displayed (a) colonization of the epidermis and mesocarp by M. fructicola with thin and thick hyphae, (b) collapse and disruption of epidermal and mesocarpic cells, (c) lysogenic cavities in the subepidermis and mesocarp, (d) degradation of the cuticle and epidermis, and (e) M. fructicola sporulation. M. fructicola is active during latent infections because slow and progressive colonization of nectarine subcuticular cells by the fungus occurs