Growth,development, feeding preference,and food consumption and utilization by tobacco hornworm on tobacco mosaic virus-infected and non-infected tobacco leaves

Summary Plant disease may cause a variety of changes in plants which influence their suitability to insect herbivores. The reported physiological changes in tobacco due to infection by tobacco mosaic virus have the potential to influence the feeding, growth and behavior of the tobacco hornworm,Manduca sexta. However, feeding on foliage of systematically infected plants had no statistically significant effects on development time, mean pupal weight or the amount of foliage consumed by 4th instars. Although an initial preference was exhibited by larvae for healthy leaves after about 72 h no differences were observed. These results do not support the results of previous research on the influence of tobacco mosaic virus-infected plants on the tobacco hornworm.Scientific contribution No. 8130, article No. A-5071, of the Maryland Agricultural Experiment Station, Department of Entomology     

Effect of inhibitors of protein synthesis from plants on tobacco mosaic virus infection

Summary Ricin, abrin, modeccin, gelonin andMomordica charantia inhibitor, as well as crude extracts ofBryonia dioica seeds and ofDianthus caryophyllus leaves, each inhibit protein synthesis in a rabbit reticulocyte lysate and reduce local lesion production by tobacco mosaic virus, thus resembling the effects of the pokeweed antiviral peptide.     

Biological relationship of cucumis virus-3 and powdery mildew fungus in bottle gourd

Summary 2 kinds of interrelationship between cucumis virus-3 and powdery mildew fungus in bottle gourd were noted. The fungal conidia transmitted the mosaic virus infection from infected to healthy bottle gourd plants with ease. The transmission relation was found to be external. Powdery mildew symptoms were restricted on mosaic infected leaves and appeared late, while virus symptoms appeared precociously in mildew infected plants.     

The effect of actinomycin D on the production of viruses by the protoplasts of Chinese cabbage infected in vitro by the yellow mosaic virus of turnips]

Chinese Cabbage (Brassica sinensis L. var. Cantonner) protoplasts were infected by Turnip yellow mosaic virus (TYMV) and inoculated in the presence or absence of actinomycin D. Virus production was determined 40 hrs. after inoculation, the time required for the virus replication cycle to be terminated. While actinomycin D had no effect on TYMV production when present at a concentration of 1 microng/ml, a 50 to 80% inhibition of virus production was noticed at concentrations of the order of 5 to 10 microng/ml, and the inhibition reached 90% with 25 microng/ml.     

The spread of Tobacco mosaic virus infection: insights into the cellular mechanism of RNA transport

Interactions of plant cells with pathogens or other biotic or abiotic environmental factors can give rise to systemic defense responses that rely upon the cell-to-cell and systemic transport of specific signals. A novel type of systemic signaling was revealed by recent evidence indicating the existence of RNA species that travel cell to cell and through the vasculature. The most compelling evidence for intercellular and systemic transport of RNA in plants is provided by viroids and viruses that apparently use the endogenous transport machinery to spread infection. The cell to cell movement of plant viruses occurs through small pores in the cell wall known as plasmodesmata and depends on virus-encoded 'movement proteins'. This review summarizes current knowledge of Tobacco mosaic virus infection with emphasis on the mechanism by which this virus targets its RNA genome from sites of replication to plasmodesmata to achieve intercellular spread.     

Cone mosaic in a teleost retina: No difference between light and dark adapted states

Summary The mosaic arrangement of retinal cones in the eye of the African cichlid fish,Haplochromis burtoni, is the same in both light and dark adapted states. This is in contrast to Kunz' claim² that the retinal mosaic pattern changes from a square to a row type during dark adaptation, in the guppy (Poecelia reticulata). Kunz' histological procedure may account for this difference in results.Acknowledgments. This work was supported by grants from the Whitehall Foundation and NIH EY02284. I thank L. Shelton for expert histological assistance.     

Untersuchungen über die Nikotinbildung des Tabaks

Summary During germination the tobacco seedling produces nicotine from proteins accumulated in the seed. Later on the nicotine formation of the growing tobacco plant is dependent on the protein synthesis in its root. The comparison of theprotein production by the tobacco root with thenicotine content of the whole plant shows an interesting parallelism.     

Differential leaf resistance to insects of transgenic sweetgum (Liquidambar styraciflua) expressing tobacco anionic peroxidase

Leaves of transgenic sweetgum (Liquidambar styraciflua) trees that expressed tobacco anionic peroxidase were compared with leaves of L. styraciflua trees that did not express the tobacco enzyme. Leaves of the transgenic trees were generally more resistant to feeding by caterpillars and beetles than wild-type leaves. However, as for past studies with transgenic tobacco and tomato expressing the tobacco anionic peroxidase, the degree of relative resistance depended on the size of insect used and the maturity of the leaf. Decreased growth of gypsy moth larvae appeared mainly due to decreased consumption, and not changes in the nutritional quality of the foliage. Transgenic leaves were more susceptible to feeding by the corn earworm, Helicoverpa zea. Thus, it appears the tobacco anionic peroxidase can contribute to insect resistance, but its effects are more predictable when it is expressed in plant species more closely related to the original gene source. Received 4 March 1998; received after revision 27 April 1998; accepted 30 April 1998     

Characteristics of mosaic muscle growth in rainbow troutSalmo gairdneri

Summary There are 4 stages in the growth of mosaic (axial) muscle, which is the predominating tissue in trout; the stages are distinguishable by the modal values and range of their fibre diameters over the size range 2.3 to 50+cm fork length. Up to 50 cm, most of the increase in mosaic muscle is attributable to continuous recruitment of new fibers. Beyond 50 cm, further growth is a result of increase in diameter of existing fibers.     

Occurrence of a pheromone-producing gland in female tobacco beetles

Summary A pheromone-producing gland was discovered in the second abdominal segment of virgin female tobacco beetles,Lasioderma serricorne (Fabricius). The gland duct extends to an orifice below the genital pore and is supported by a rigid invagination of the integument. Hexane extracts of intact pheromone glands were found attractive to male tobacco beetles and also induced high receptor potentials in the olfactory sensilla of the antennae of maleL. serricorne. A surface extract of virgin females proved to be significantly more attractive than an extract of pheromone glands.     

Double cone mosaic pattern in the retina of larval and adult piranha,Serrasalmus spilopleura

The mosaic pattern of double cones of retinas in larval and adult piranha,Serrasalmus spilopleura, was examined. Samples from two habitats in the same reservoir, characterized by different light conditions, were examined. The same square pattern was found in all sampled retinas indicating that, for this species, there is no apparent relation between the patterns of double cone arrangement and environmental luminosity.     

Cone mosaics in a teleost retina: Changes during light and dark adaptation

Summary The square mosaic pattern of retinal cones in the guppy,Poecilia reticulata, changes during dark adaptation into a row mosaic. The functional significance of this change is discussed.Thanks are due to Dr A. Yacob, Biology Department, Mosul University, for supplying the photomicrograph for figure 2A, and to Dr C. Wise, Department of Zoology, University College, Dublin, and B. A. Collins, The Marine Biological Laboratory, Woods Hole, for technical assistance.     

Elektronenoptische Untersuchungen des Hauptstrom-Rauchkondensats der Partikelphase des Cigaretten- und Cigarrenrauchs

Summary Report on a method to produce, without refrigeration and solvents, a tobacco smoke condensate of the tobacco main-stream smoke of the particulate phase. Identification obtained by the electron fine beam diffraction of crystals in the sediment of the smoke condensate of cigarettes and cigars.

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Wissenschaftlicher Gast am Institut für Elektronenmikroskopie des Fritz-Haber-Instituts der Max-Planck-Gesellschaft.     

Satellite RNA (RNA3) of tomato black ring virus is found with one of the 2 major RNAs (RNA2) in a new capsid nucleoprotein]

Tomato Black Ring Virus (TBRV) like other NEPOviruses posseses two nucleoproteins M and B and two major RNAs, RNA1 and RNA2 respectively distributed in B and M. A new nucleoprotein has just been discovered and comprises one molecule of RNA2 associated with one molecule of RNA3. RNA3 is a small RNA of molecular weight 500,000 d considered to be a satellite RNA. Its level appears to depend on the infection stage, local or systemic. RNA3 is able to modify the relative proportions of nucleoproteins M and B and their respective RNAs. The satellite RNA, might be part of the genome and represent a monocistronic mRNA for protein capsid synthesis. However it seems perhaps more tempting to correlate TBRV-RNA3 with satellite RNA5 of certain strains of Cucumber mosaic virus.     

Arylpyridyl-thiosemicarbazones: A new class of anti-juvenile hormones active against Lepidoptera

Summary A new class of anti-juvenile hormone agents is described. Active anti-juvenile hormone compounds were either diazine thiosemicarbazones or aryl substituted pyridyl thiosemicarbazones, synthesized from substituted benzaldehydes. While many analogs in these classes showed feeding and growth inhibition in a variety of insects, a select group caused formation of precocious pupal characteristics inAgrotis ipsilon (black cutworm) andHeliothis virescens (tobacco budworm) and black cuticle and precocious pupae inManduca sexta (tobacco hornworm). They were active only by diet incorporation. The symptoms of precocious development could be reversed by co-administration of a juvenoid. One of the active compounds was shown to inhibit juvenile hormone biosynthesis in vitro by corpora allata of the cockroachDiploptera punctata. However, none of the compounds were active inhibitors of purified chicken liver prenyl transferase.     

Zur Frage des Vorkommens von N-Nitroso-Verbindungen im Tabakrauch

Summary Important facts in connection with the occurrence of N-Nitroso compounds in tobacco smoke have been summarized. This paper reports on analytical methods for the identification of N-Nitroso compounds. The figures known about nitrate content and volatile bases of tobacco, as well as the nitrogen oxides and volatile bases of tobacco smoke as precursors of N-Nitroso compounds, are summarized. The third order reaction of secondary amines with an equimolar mixture of nitric oxide and nitrogen dioxide is a precondition for the formation of N-Nitroso compounds in tobacco smoke. While examining tobacco smoke for N-Nitroso compounds, temperature and time conditions have to be adapted to the natural smoking process. The use of solvent as well as cold traps has to be avoided to exclude the formation of artifacts. Analyses completed under these conditions furnished results of 0.004µg of a mixture consisting of N-Nitroso-dimethylamine and N-Nitroso-pyrrolidine, calculated as N-NO per cigarette. A number of animalexperimental preconditions are still lacking, to judge the biological effects of these extraordinarily small amounts of N-Nitroso compounds.     

Heterozygote Zentrenfusion bei einer weissen Laborratte

Summary A centric fusion of 2 acrocentric chromosomes in a female laboratory rat is described. The phenotype was normal. The new chromosome is submetacentric. Other animals of the same group showed such new chromosomes only sporadically. No information is available of chromosome mosaic, fertility or genetics of this animal.     

Über die Aktivität der Tyrosinase in Tabaksamen

Summary Water or buffered extracts from tobacco seeds (Mont Calme brun) showed both cresolase and catecholase activity of tyrosinase, which was inhibited by 10^–2 M thiourea. No difference of activity could be observed in extracts from old and fresh seeds. Unexpectedly, chlorogenic acid is not oxidized by this tyrosinase.     

Hyperthermia-induced apoptosis and the inhibition of DNA laddering by zinc supplementation and withdrawal of calcium and magnesium in suspension culture of tobacco cells

In the present paper we report examination of stereotypic hallmarks of apoptosis in heat-treated tobacco cells. Hyperthermia (44 °C, 4 h) caused apoptosis in 53.6% of cells when assayed 24 h after heat treatment. The induction of apoptosis by heat treatment was confirmed by flow cytometric assay. Cytological observations revealed condensation of the cytoplasm and nucleus, as well as nuclear collapse. DNA ladders were observed in DNA extracted from heat-treated cells, whereas DNA from control cells remained undegraded. The terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) assay revealed that 51.8% of the heat-treated cells (44 °C, 4 h) show positive reaction after a 24-h recovery. When cells were cultured in a medium supplemented with 0.4–5.0 mM ZnSO₄, internucleosomal DNA fragmentation induced by heat shock was completely negated. Strikingly, when cells were cultured in Ca²⁺ and/or Mg²⁺ free medium for 44 h followed by heat treatment, DNA laddering was not observed. The results suggest hyperthermia-induced apoptosis and a correlation between the regula tion of endonucleases and heat shock signal in apoptotic tobacco cells. Received 17 September 1998; received after revision 4 January 1999; accepted 4 January 1999     

Kristalloide Strukturen im Zytoplasma von lymphatischen Zellen verschiedener Affen

Summary In the endoplasmic reticulum of cells of spleen and lymphnodes of different monkeys, crystalloid inclusions were often found. These inclusions show a pattern of small balls with a diameter of 250 Å, which are connected by 100 Å long bridges. It is supposed that these crystalloid inclusions are produced by the lymphatic cells as a reaction to virus infection, which remains clinically non-apparent, because the same pattern was observed in cells, which were experimentally infected with yellow fever virus, West Nile virus, and rubella virus.