Properties of a new strain of tobacco streak virus from Clematis vitalba (Ranunculaceae)

A distinct strain of tobacco streak virus (TS V/Cle), isolated in Yugoslavia from wild Clematis vitalba showing chlorotic spots or yellow netting of the leaves and from many symptomless shrubs, is described. TSV/Cle was seed transmitted in C. vitalba (70%), and in the experimental hosts Chenopodium quinoa (80%), Nicotiana benthamiana and N. megalosiphon. It was also detected in the pollen of infected C. quinoa. Purified virus preparations mostly contained quasi-spherical particles measuring 24–26 × 28, 26–28 × 28–30 and 28–31 × 32–36 mn, and sedimented in sucrose density gradient and analytical centrifugation as three components with sedimentation coefficients of 76S, 87S and 98S. The virus contained a single polypeptide species of mol. wt of c. 25 000. Unfractionated TSV/Cle preparations contained four RNA species with mol. wts, estimated by gel electrophoresis in agarose, of 1.1 × 10⁶, 0.9 × 10⁶, 0.7 × 10⁶ and 0.3 × 10⁶. In comparative experiments, TSV/Cle differed from four reference strains of TSV (TSV/B, TSV/HF, TSV/RN, and TSV/Ro) in host range and in symptoms induced in some common hosts. In agar gel double diffusion tests it was more closely related to TSV/B and TSV/M (SDI = 5) than to TSV/HF (SDI = 7), TSV/RN (SDI = 7) or TSV/Ro (SDI = 5–8). Immunoelectrophoresis experiments clearly distinguished TSV/Cle from the reference strains. TSV/Cle strain was detected in C. vitalba plants from distant and climatically different regions in Yugoslavia.     

Type specimens of G. E. Post in Beirut and The Natural History Museum,London

The Flora of Syria, Palestine and Sinai, a pioneer Flora of the region, was published in 1896 by George Edward Post (1838–1909). Lesser known are his series of Diagnoses plantarum novarum orientalium, published in the Journal of the Linnean Society Botany, and 10 papers, Plantae Postianae, which appeared in Swiss journals from 1890 to 1900. A greatly expanded second edition of the Flora was prepared by John Edward Dinsmore and published in Beirut in 1932 and 1933. Post's plant collection is part of the Post Herbarium (BEI), with about 63 000 specimens, that has been well maintained, despite civil war and inadequate staffing. This work involves the identification of around 150 types in BEI and BM, and improvement of the accessibility of the specimens. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 159 , 315–321.     

Inhibition by α-Amanitin of Adenovirus 12 Replication in Human Embryo Kidney Cells and of Adenovirus Transformation of Hamster Cells

ADENOVIRUS infection of human embryonic kidney (HEK) cultures seems to induce cellular RNA synthesis, which is preceded by a transient increase in the activities of the Mg²⁺-activated and Mn²⁺-(NH₄)₂SO₄-activated DNA dependent RNA polymerases and in the rate of histone acetylation¹. The two polymerase reactions, assayed in isolated cell nuclei, apparently reflect the activities of distinct nucleolar and nucleo-plasmic RNA polymerases^2,3. We were therefore prompted to test the effect of a specific inhibitor of the mammalian DNA-dependent RNA polymerase function, α-amanitin, on the multiplication of adenovirus. α-Amanitin is a bicyclic octapeptide isolated from the poisonous mushroom Amanita phalloides⁴ and which blocks RNA synthesis in intact animals^5,6. Nuclei isolated from the livers of such animals show a reduced activity of the RNA polymerases associated with nucleoplasm^5,6 and the nucleolus⁶.     

Effect of Rifampicin on the Development of Tumours induced by Adenovirus in Male Hamsters

INITIAL in vitro studies established that rifampicin, one of a group of rifamycin SV derivatives^1,2, prohibits bacterial growth and phage replication by binding to a polypeptide component of the microbial DNA-dependent RNA polymerase^3–7. The trachoma agent and related psittacosis-lymphogranuloma agents are also inhibited in vitro and in embryonated eggs by this drug⁸. Further studies have shown that rifampicin is active against a number of bacteria in vivo, both after parenteral and oral administration^1,9,10. It also inhibits malaria in mice¹¹ and trachoma in monkeys^12,13 and is of special value in the treatment of human tuberculosis^14–16. The low toxicity of the rifamycins in mammals¹⁷ has been attributed to the observed relative insensitivity of mammalian RNA polymerase to the rifamycins in vitro^3,18.     

Phenetic analysis of Anemone coronaria (Ranunculaceae) and related species

This study clarifies the taxonomic status of Anemone coronaria and segregates the species and A. coronaria infraspecific variants using morphological and morphometric analyses. Principal component analysis of the coronaria group was performed on 25 quantitative and qualitative characters, and morphometric analysis of the A. coronaria infraspecific variants was performed on 21 quantitative and qualitative characters. The results showed that the A. coronaria group clustered into four major groups: A. coronaria L., A. biflora DC, A. bucharica (Regel) Juz.ex Komarov, and a final group including A. eranthioides Regel and A. tschernjaewii Regel. The data on the A. coronaria infraspecific variants clustered into six groups: A. coronaria L. var. coronaria L., var. cyanea Ard., var. albiflora Rouy & Fouc., var. parviflora Regel, var. ventreana Ard., and var. rissoana Ard.  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 153 , 417–438.