scispace - formally typeset
Search or ask a question

Showing papers by "Tom J. Mabry published in 1994"


Journal ArticleDOI
TL;DR: It is demonstrated that PAP inactivates pokeweed ribosomes (and is therefore potentially toxic to pokeweed cells) and supports the local suicide model for PAP's in vivo antiviral mechanism.
Abstract: Pokeweed antiviral protein (PAP) and other ribosome-inactivating proteins (RIPs) had previously been thought to be incapable of attacking conspecific ribosomes, thus having no effect on endogenous processes. This assertion conflicts with a model for PAP's in vivo antiviral mechanism in which PAP (a cell wall protein) selectively enters virus-infected cells and disrupts protein synthesis, thus causing local suicide and preventing virus replication. We show here that pokeweed (Phytolacca americana) ribosomes, as well as endod (Phytolacca dodecandra) ribosomes, are indeed highly sensitive to inactivation by conspecific RIPs. Ribosomes isolated from RIP-free pokeweed and endod suspension culture cells were found to be highly active in vitro, as measured by poly(U)-directed polyphenylalanine synthesis. Phytolacca ribosomes challenged with conspecific RIPs generated dose-response curves (IC50 of 1 nM PAP or dodecandrin) very similar to those from wheat germ ribosomes. To determine if Phytolacca cells produce a cytosolic 'anti-RIP' protective element, ribosomes were combined with Phytolacca postribosomal supernatant factors from culture cells, then challenged with conspecific RIPs. Resulting IC50 values of 3-7 nM PAP, PAP-II, PAP-S or dodecandrin indicate that supernatants from these Phytolacca cells lack a ribosomal protective element. This research demonstrates that PAP inactivates pokeweed ribosomes (and is therefore potentially toxic to pokeweed cells) and supports the local suicide model for PAP's in vivo antiviral mechanism. The importance of spatial separation between PAP and ribosomes of cells producing this RIP is emphasized, particularly if crop plants are transformed with the PAP gene to confer antiviral protection.

79 citations


Book
01 Jan 1994
TL;DR: This chapter discusses the evolution of the Sieve-Element Plastids in the Caryophyllales and some of the relationships between these characters and those of the Families Sometimes Included in or Most Often Allied to the Order.
Abstract: Dedication to Arthur Cronquist.- 1 Nomenclatural and Taxonomic History.- 1.1 Introduction.- 1.2 Early History.- 1.3 Refinement of the Definition from Alexander Braun (1864) to the Present.- 1.4 Use of Characters Other Than Classical Morphology in Defining the Order.- 1.5 Inclusion or Exclusion of some Particular Families.- 1.6 Recent Developments.- 1.6.1 Families Now Generally Included in the Caryophyllales.- 1.6.2 Families Now Generally Excluded from the Caryophyllales, Although Sometimes Included by Past Authors.- 1.6.3 Summary of Our Present Knowledge of the Caryophyllales.- 1.6.4 Preferred Classification of Caryophyllales by Cronquist.- 1.6.5 Preferred Classification of Caryophyllales by Thorne.- 1.6.6 Relationships of the Caryophyllales.- References.- 2 Chromosome Numbers and Their Phyletic Interpretation.- 2.1 Introduction.- 2.2 Chromosome Numbers of Caryophyllales.- 2.3 Discussion and Conclusions.- References.- 3 Vascular Tissues.- 3.1 Introduction.- 3.2 Materials and Methods.- 3.3 Primary Vascular Systems.- 3.3.1 Procambial Differentiation in the Shoot.- 3.3.2 Sympodial Nature of Primary Shoot Vasculature.- 3.3.3 Differentiation Patterns of Bundles.- 3.3.3.1 Phytolacca dioica.- 3.3.3.2 Notable Variations in Other Centrosperms.- 3.3.4 Leaf Venation.- 3.4 Secondary Thickening.- 3.4.1 Occurrence of Normal and Anomalous Types.- 3.4.2 Nature of Anomalous Vascular Tissues.- 3.4.2.1 Bidirectionally-Dividing Supernumerary Cambium.- 3.4.2.2 Initiation and Progression of Vascular Cambia in Seedlings.- 3.4.2.3 Origin of Additional Supernumerary Cambia and Nature of Connections.- 3.4.3 Structure and Cell Types of Secondary Xylem.- 3.4.3.1 Portulacineae (Sensu Thorne 1983).- 3.4.3.2 Phytolaccaceous Alliance.- 3.4.3.3 Other Betalain-Containing Families.- 3.4.3.4 Anthocyanin-Containing Families.- 3.5 Extraxylary Sclerenchyma of Stems.- 3.6 Phylogenetic Analysis.- References.- 4 Epicutieular Wax Ultrastructure and Systematics.- 4.1 Introduction.- 4.2 Wax Ultrastructure of Caryophyllales.- 4.3 Relations Within the Order.- 4.4 Wax Ultrastructure and Position of the Order.- References.- 5 Sieve-Element Plastids: Their Significance for the Evolution and Systematics of the Order.- 5.1 Introduction.- 5.2 The Sieve-Element Plastid Characters.- 5.2.1 Forms and Types of Sieve-Element Plastids.- 5.2.2 Sizes of Sieve-Element Plastids.- 5.3 The Distinctive Characters of Sieve-Element Plastids in the Caryophyllales.- 5.4 The Distribution of Forms and Sizes of Sieve-Element Plastids in the Higher Taxa of the Caryophyllales.- 5.5 The Sieve-Element Plastids of the Families Sometimes Included in or Most Often Allied to the Caryophyllales.- 5.6 The Putative Evolution of the Sieve-Element Plastids in the Caryophyllales.- 5.7 Relationships of the Order Caryophyllales.- 5.8 Addendum: On Phytoferritin in Plastids of Phloem Cells.- References.- 6 Flower Morphology and Ontogeny.- 6.1 Introduction.- 6.1.1 Materials and Methods.- 6.1.2 What Groups Can Be Used as Homogeneous Units?.- 6.1.2.1 Commentary on Families.- 6.2 Results.- 6.2.1 Observations on some Individually Treated Genera.- 6.2.2 Ontogeny of the Flowers, Especially of the Androecium and Petals.- 6.2.2.1 Families with Centrifugally Originating Stamens.- 6.2.2.2 Comments on Families with Successively Originating Stamens.- 6.2.2.3 Flower Ontogeny of Gyrostemonaceae.- 6.2.3 Gynoecium.- 6.2.3.1 Types of Gynoecia.- 6.2.3.2 Ontogeny of Carpels.- 6.2.3.3 Stigmas, Styles, Pollen Tube Transmitting Tissue and "Free-Central Placenta".- 6.3 Conclusions.- References.- 7 Pollen Morphology and Exine Ultrastructure.- 7.1 Introduction.- 7.2 Materials and Methods.- 7.3 Results.- 7.3.1 Caryophyllales Pollen Description.- 7.3.2 Tectum.- 7.3.3 Apertures.- 7.3.4 Exine Structure.- 7.3.5 Pollen Descriptions of the Caryophyllales Families.- 7.4 Discussion.- 7.4.1 Pollen Data and Molecular Results.- 7.5 Summary.- References.- 8 Phylogenetic Relationships Using Restriction Site Variation of the Chloroplast DNA Inverted Repeat.- 8.1 Introduction.- 8.2 Materials and Methods.- 8.3 Results and Discussion.- 8.3.1 rpl2 Intron Loss.- 8.3.2 Phylogenetic Analysis of Inverted Repeat Restriction Site Mutations.- 8.3.3 Nepenthes and the Caryophyllales.- 8.4 Conclusions.- References.- 9 Gene Sequence Data.- 9.1 Introduction.- 9.2 Materials and Methods.- 9.2.1 Materials.- 9.2.2 DNA Extractions, Cloning, Amplification, and Sequencing.- 9.2.3 Analysis of Data.- 9.3 Results and Discussion.- 9.3.1 General.- 9.3.2 Clade I: Chenopodiaceae and Amaranthaceae.- 9.3.3 Clade II: Caryophyllaceae.- 9.3.4 Clade III: Basellaceae, Portulacaceae, Cactaceae, and Didiereaceae.- 9.3.5 Clade IV: Phytolaccaceae, Petiveriaceae, Nyctaginaceae, and Gisekia.- 9.4 Conclusions.- References.- 10 Chemical Review and Evolutionary Significance of the Betalains.- 10.1 Introduction.- 10.2 Biogenesis of Betalains.- 10.3 Evolutionary Significance of Betalains.- 10.4 Value of Chemotaxonomic Data in Studies of the Caryophyllales.- 10.5 Current and Future Studies.- References.- 11 Recent Advances in Betalain Analysis.- 11.1 Introduction.- 11.2 General Procedures.- 11.3 High Performance Liquid Chromatography.- 11.4 Nuclear Magnetic Resonance Spectroscopy.- 11.5 Mass Spectrometry.- References.- 12 Cladistic and Phenetic Studies.- 12.1 Summary.- 12.2 Introduction.- 12.3 Materials: Taxa.- 12.4 Materials: Characters.- 12.5 Methods.- 12.6 Results and Discussion.- 12.7 Conclusion.- Appendix A Characters, States, and Codings, with Notes on Literature Sources, Homology, Sampling, and Variability.- Appendix B Matrix of Coding Assignments.- References.- 13 Putative Origin and Relationships of the Order from the Viewpoint of Developmental Flower Morphology.- 13.1 Introduction.- 13.2 The Fascicled Centrifugal Androecium as a Basis of Argumentation Concerning the Origin of the Caryophyllales.- 13.3 The Gynoecium as a Basis of Argumentation Concerning the Relationships of the Caryophyllales.- 13.4 Conclusion.- References.- 14 A Note on the Relationships of the Order Within the Angiosperms.- References.- 15 Lyallia kerguelensis Hook. f. and Its Artificial Propagation.- 15.1 Introduction.- 15.2 Taxonomic Description.- 15.3 Geographical Distribution and Ecology.- 15.4 Material Examined.- 15.5 Artificial Propagation.- References.- Genera Index.

41 citations


Journal ArticleDOI
TL;DR: In this article, the most active antioxidant fraction from the organic extract of Zingiber cassumunar rhizomes was found to contain three potent antioxidants (Cassumunarin A, B, and C), which were shown by spectral methods to represent a new type of complex curcumin.

35 citations


Journal ArticleDOI
TL;DR: In this paper, 6,8-Dihydroxykaempferol 3-rutinoside, along with quercetin and its 3- O -rutino-7-glucoside, were isolated from the leaves of Withania somnifera.

33 citations


Journal ArticleDOI
TL;DR: The underground caudex of the cycad Stangeria eriopus is used extensively by several ethnic groups in South Africa, mainly as an ingredient in magical potions but also as an emetic, and high carbohydrate content with only small percentages of fat, protein, fibre and ash is given.

26 citations


Journal ArticleDOI
TL;DR: Temperature-programmed retention index sets as measured on DB-5 and DB-17 dual-capillary columns were characteristic of each amino acid and thus useful for the screening of amino acids by computer I matching.

25 citations


Journal ArticleDOI
TL;DR: Taxonomic implications of compound patterns in the species examined includes: incorporation of Dugaldia, Plummera and Macdougalia into a broader concept of Hymenoxys ; and recognition of Tetraneuris as a distinct genus.

21 citations


Journal ArticleDOI
TL;DR: The whole plant flavonoid chemistry was strikingly different from that found previously in chitin-treated cell suspension cultures of the same plant.

21 citations


Journal ArticleDOI
TL;DR: A new acylated flavone C-glycoside, apigenin 6-C-alpha-L-rhamnopyranoside-8-C, was isolated from rhizomes of Glycyrrhiza eurycarpa and its structure was established on the basis of spectroscopic data.

19 citations




Journal ArticleDOI
TL;DR: Hasakol, an inhibitor against Ba++-induced contraction of smooth muscles, has been synthesized in six steps starting from 7-O-geranylumbelliferone via an improved Claisen rearrangement as mentioned in this paper.
Abstract: Hasakol, an inhibitor against Ba++-induced contraction of smooth muscles, has been synthesized in six steps starting from 7-O-geranylumbelliferone via an improved Claisen rearrangement.