John F. Jackson

Essential oils and waxes.

Olive Oil Analysis.- 1 Introduction.- 2 Quality Tests of Olive Oil-Determination of Acidity and Oxidation.- 2.1 Acidity.- 2.2 Oxidation.- 3 Sensory Evaluation of Olive Oil.- 4 Determination of Certain Constituents of Olive Oil.- 4.1 Chlorophyll Determination.- 4.2 Determination of Phenols.- 5 Moisture Determination.- 5.1 Moisture Determination by Infrared Balance.- 6 Determination of Soap Content.- 7 Olive Oil Adulteration - Adulteration and Genuineness Tests.- 7.1 Methods and Techniques of Detecting Adulteration.- 7.2 Adulteration Tests Based on Color Formation.- 7.3 Adulteration Tests Based on Residue or Clouding Formation.- 7.4 Detection of Oil Adulteration by a UV Lamp.- 7.5 Detection of Olive Oil Purity by Infrared Spectrophotometry.- References.- Analysis of Essential Oils of Tea.- 1 Introduction.- 2 Isolation of Essential Oils.- 2.1 Steam Distillation Under Reduced Pressure (SDR).- 2.2 Simultaneous Distillation and Extraction (SDE).- 2.3 Head Space Gas Analysis.- 3 Separation and Identification of Essential Oil Components from Tea.- 3.1 Gas Chromatography.- 3.2 Gas Chromatography-Mass Spectrometry (GC-MS).- 3.3 Gas Chromatography-Infrared Spectrometry-Mass Spectrometry (GC-IR-MS).- 4 Components of the Essential Oil.- 4.1 Comparison of the Main Components in Various Teas.- 4.2 Specific Components of the Essential Oils.- 5 Pattern Analyses of Gas Chromatograms.- References.- Special Methods for the Essential Oils of the Genus Thymus.- 1 Introduction.- 2 Plant Material.- 3 Extraction.- 4 Analytical Methodology.- 4.1 Qualitative Analysis.- 4.2 Quantitative Analysis.- 5 Conclusions.- References.- Chemical Races Within the Genus Mentha. L..- 1 Introduction.- 2 Biosynthesis of Mentha Essential Oils.- 3 Chemical Races.- 3.1 Oils Rich in Acyclic Compounds.- 3.2 Oils Rich in 2-Substituted Compounds.- 3.3 Oils Rich in 3-Substituted Compounds.- 4 Conclusions.- References.- Special Methods for the Essential Oil of Ginger.- 1 Introduction.- 1.1 Description and Use.- 1.2 Chemical Composition.- 1.3 Isolation, Separation and Quality Evaluation of Ginger Oil..- 2 Traditional Methods of Extraction, Separation, and Control.- 2.1 Traditional Isolation Methods.- 2.2 Traditional Separation Methods.- 2.3 Traditional Quality Control.- 3 Modern Methods of Extraction, Separation, and Identification.- 3.1 Introduction.- 3.2 Modern Methods of Isolation.- 3.3 Modern Methods of Separation.- 3.4 Modern Methods of Identification.- References.- GC-MS (EI, DCI, NCI, SIM) SPECMA Bank Analysis of Volatile Sulfur Compounds in Garlic Essential Oils.- 1 A Short Survey of the Chemistry of Garlic.- 2 Analytical Methods Used for Identification of Sulfur Compounds in Garlic Essential Oil.- 2.1 GC-MS (EI, PCI, NCI) of Garlic Essential Oils.- 2.2 Kovats Indices as Filters and Their Properties.- 2.3 The SPECMA Bank.- 3 GC-MS Analyses of Two Garlic Essential Oils Originating from France (Provence) and Mexico.- 3.1 Analyses and Composition.- 3.2 Mechanisms of Formation of Sulfide Derivatives.- 4 Conclusion.- References.- Analysis of Juniper and Other Forest Tree Oil.- 1 Introduction.- 2 Sample Collection.- 2.1 Sampling.- 2.2 Sample Sizes.- 2.3 Diurnal, Seasonal, and Ontogenetic Variation.- 3 Oil Extraction.- 4 Chemical Analysis.- 4.1 Gas Chromatography.- 5 Component Identification.- 5.1 GC/MC Computer Searches.- 6 Applications of Terpenoid Data.- 6.1 Analyses of Hybridization and Introgression.- 6.2 Studies of Geographic Variation.- 6.3 Taxon Level Differences and Evolutionary Studies.- References.- Cedar Wood Oil - Analyses and Properties.- 1 Introduction.- 2 Sample Collection.- 3 Oil Extraction.- 4 Chemical Analysis.- 4.1 Gas Chromatography.- 5 Identification.- 5.1 GC/MS.- 6 Properties.- 6.1 Antimicrobial Activities.- 6.2 Insecticidal Activities.- 6.3 Termiticidal Activities.- References.- Analysis of Croton Oil by Reversed-Phase Overpressure-Layer Chromatography.- 1 Introduction - Overpressure-Layer Chromatography as a Separatory Technique.- 2 Phorbol Ester Constituents of Croton Oil.- 3 Separation of the Phorbol Esters of Croton Oil.- 3.1 Two-Dimensional Thin Layer Chromatography.- 3.2 Reversed-Phase Overpressure Layer Chromatography.- 4 Summary and Conclusions.- References.- Rotation Locular Countercurrent Chromatography Analysis of Croton Oil.- 1 Introduction.- 2 Croton Oil, the Seed Oil of Croton tiglium.- 3 RLCC Analysis of Croton Oil.- 3.1 Introduction.- 3.2 Experimental Details and Discussion.- 4 Summary and Conclusion.- References.- Oils and Waxes of Eucalypts Vacuum Distillation Methodl for Essential Oils.- 1 Introduction.- 2 Chemical Composition of Eucalyptus Oils and Waxes.- 3 Methods of Analyses of Eucalyptus Waxes.- 4 Methods of Analysis of Eucalyptus Oils.- 5 Vacuum Distillation Method for Essential Oils.- 5.1 Preparation of Leaf Powder.- 5.2 Distillation.- 5.3 Notes.- References.- Analysis of Epicuticular Waxes.- 1 Introduction.- 2 Extraction of Epicuticular Wax.- 3 Fractionation of Wax Components.- 3.1 Column Chromatography.- 3.2 Thin Layer Chromatography (TLC).- 4 Analysis of Wax Components.- 4.1 Analysis of Hydrocarbon by Gas Liquid Chromatography (GLC).- 4.2 Analysis of Wax Esters.- 4.3 Analysis of Free Alcohols and Fatty Acids.- 4.4 Analysis of Aldehydes.- 4.5 Analysis of ?-Diketones.- 5 Conclusion.- References.- Analysis of Flower and Pollen Volatiles.- 1 Introduction.- 2 Flower Volatile Chemistry.- 3 Overview of Methodology.- 3.1 Volatile Collection.- 3.2 Volatile Analysis.- 3.3 Cautionary Notes.- 4 Details of Collection Methods.- 4.1 Extraction and Distillation.- 4.2 Headspace Cold-Trapping.- 4.3 Direct Headspace Sampling.- 4.4 Headspace Sorption.- 4.5 Passive Sorption.- References.- Bioactivities of Diterpenoids from Marine Algae.- 1 Introduction.- 2 Antimicrobial Activity.- 2.1 Background.- 2.2 Description of the Methods.- 2.3 Antimicrobial Diterpenoids from Seaweeds.- 3 Antialgal Activity.- 3.1 Background.- 3.2 Description of the Method.- 3.3 Antialgal Diterpenoids from Seaweeds.- 4 Cytotoxic Activity and Other Related Activities.- 4.1 Background.- 4.2 Description of the Methods.- 4.3 Cytotoxic and Antimitotic Diterpenoids from Seaweeds.- 5 Ichthyotoxicity and Other Defensive Bioactivities.- 5.1 Background.- 5.2 Description of the Methods.- 5.3 Ichthyotoxic and Other Defensive Diterpenoids from Seaweeds.- 6 Molluscicidal Activity.- 6.1 Background.- 6.2 Description of the Methods.- 6.3 Molluscicidal Diterpenoids from Seaweeds.- 7 Other Bioactivity Data on Diterpenoids from Seaweeds.- 8 Concluding Remarks.- References.- Determination of Waxes Causing Water Repellency in Sandy Soils.- 1 Introduction.- 2 Assessment of Water Repellency of Soils.- 2.1 Molarity of the Ethanol Droplet (MED) Method.- 2.2 Capillary Rise Technique.- 2.3 Other Test Methods.- 3 Extraction of Water-Repellent Waxes.- 4 Significance and Conclusions.- References.- Analysis of Monoterpene Hydrocarbons in the Atmosphere.- 1 Introduction.- 2 Sampling and Concentration.- 2.1 Adsorption Method.- 2.2 Grab Sampling.- 3 GC, GC/MS Method.- 3.1 Packed GC/MS (SIM).- 3.2 Capillary GC (FID).- 3.3 Capillary GC/MS.- 4 Calibration.- 5 Features of Atmospheric Monoterpenes.- References.- Evaluation of Antimicrobial Activity of Essential (Volatile) Oils.- 1 Introduction.- 2 Extraction of Plant Volatile Oil.- 3 Evaluation of Antimicrobial Properties of Volatile Oils.- 3.1 Antibacterial Testing.- 3.2 Antifungal Testing.- 4 Antimicrobial Activity of Volatile Oils.- 5 Future Developments in Volatile Oils.- References.- Organization of Rapid Analysis of Lipids in Many Individual Plants.- 1 Introduction.- 2 Analyses for Total Lipid Content.- 3 Analyses for Fatty Acid Composition.- 4 Analyses for Glyceride Structure.- 5 Analyses for Other Lipid Constituents.- 6 Analyses for Lipoxygenase.- References.

Phytic acid in pollen

Abstract Phytic acid has been identified by paper electrophoresis and NMR spectroscopy in extracts of pollen from Petunia hybrida . In this species pollen wa

Plant Cell Wall Analysis

Fractionation of Cell Wall Components.- 1 Introduction.- 2 Polysaccharides.- 2.1 Precipitation Reactions.- 2.1.1 Adjustment of pH.- 2.1.2 Precipitation with Organic Solvents.- 2.1.3 Precipitation with Inorganic Salts.- 2.1.4 Precipitation with Iodine.- 2.1.5 Precipitation with Ionic Detergents.- 2.2 Chromatography.- 2.2.1 Size Chromatography.- 2.2.2 Ion Exchange Chromatography.- 2.2.3 Affinity Chromatography.- 2.3 Electrophoresis.- 2.3.1 Moving Boundary Electrophoresis.- 2.3.2 Paper Electrophoresis.- 2.4 Miscellaneous Polysaccharide Methods.- 2.4.1 Cellulose.- 2.4.2 Polysaccharide Derivatives.- 3 Proteins and Glycoproteins.- 3.1 Precipitation Reactions.- 3.1.1 Precipitation with Ammonium Sulphate.- 3.1.2 Precipitation with Trichloroacetic Acid.- 3.2 Chromatography.- 3.2.1 Size Chromatography.- 3.2.2 Ion Exchange Chromatography.- 3.3 Electrophoresis.- 3.3.1 Sodium Dodecylsulphate-Polyacrylamide Gel Electrophoresis.- 3.3.2 Isoelectric Focusing.- 4 Lignins.- References.- Isolation and Analysis of Cell Wall Polymers from Olive Pulp.- 1 Introduction.- 2 Isolation of Cell Walls from Olive Pulp.- 2.1 Preparation and Use of Alcohol-Insoluble Residue (AIR) - General Considerations.- 2.2 Preparation of Cell Wall Material (CWM).- 2.2.1 Material Solubilized During the Preparation of CWM.- 3 Sequential Extraction of Cell Wall Polymers.- 3.1 General Considerations.- 3.2 Sequential Extraction.- 3.2.1 General Comments to the Method.- 4 Fractionation of the Extracted Cell Wall Polysaccharides.- 4.1 General Considerations.- 4.2 Graded Precipitation with Ethanol.- 4.3 Anion-Exchange Chromatography.- 4.3.1 Anion-Exchange Chromatography of Pectic Polysaccharides.- 4.3.2 Anion-Exchange Chromatography of Hemicellulosic Polysaccharides.- 4.4 Fractionation of Acidic Xylans.- 5 Chemical and Spectroscopic Analysis.- 5.1 Neutral Sugars.- 5.2 Uronic Acid.- 5.3 Hydroxyproline Estimation.- 5.4 Methylation Analysis.- 5.4.1 Hakomori Methylation.- 5.4.2 Ciucanu and Kerek Methylation.- 5.4.3 Carboxyl-Reduction of Methylated Polysaccharides.- 5.4.4 Comments on Results of Methylation Analysis.- 5.5 13C-NMR Studies on Cell Wall Polysaccharides.- 5.6 Fourier Transform Infrared Spectroscopy (FTIR).- 6 Concluding Remarks.- References.- Determination of Cell Wall Autolysis.- 1 Introduction.- 2 Factors Altering Cell Wall Isolation and Autolysis.- 2.1 Plant Material.- 2.2 Buffers.- 2.3 pH.- 2.4 Ionic Strength.- 3 Isolation of Active Cell Walls.- 3.1 Homogenization in Aqueous Medium.- 3.2 Filtration and Washes.- 4 Isolation of Inactive Cell Walls (Controls).- 4.1 Boiled in Hot Water.- 4.2 Boiled in Alcohol.- 4.3 Phenol-Acetic Acid-Water.- 4.4 Buffer Phenol at pH 7.- 4.5 Low Temperatures.- 5 Autolysis Incubations.- 5.1 Optimization of the Autolysis Reaction.- 5.2 General Procedure.- 6 Analysis of Autolysis Products.- 6.1 General Methods.- 6.2 Ethanol Precipitation.- 6.3 Gel Permeation Chromatography.- 6.4 Ion Exchange Chromatography.- 7 Conclusions.- References.- Cell Wall Porosity and Its Determination.- 1 Introduction.- 1.1 Biological Significance of Wall Porosity.- 1.2 Assumptions and Definitions.- 2 Microscopic Visualization of Wall Pores.- 3 Bulk Exclusion Techniques.- 3.1 Solute Exclusion.- 3.2 Long-Term-Exclusion of PEG (Polyethylenglycol).- 3.3 Gel Filtration.- 4 Tracer Techniques: Uptake of Molecules or Particles.- 4.1 Small Molecules.- 4.2 Macromolecules.- 4.3 Particles.- 5 Conclusions.- 5.1 Integration of Results from Different Methods.- 5.2 Pore Structure.- 5.3 Variations in Wall Porosity.- 5.4 Future Developments.- References.- Analysis of Chitin Biosynthesis.- 1 Introduction.- 2 Structure of Chitin.- 3 The Enzymatic Synthesis of Chitin.- 3.1 Assay of Chitin Synthase.- 3.2 Inhibition of Enzymatic Activity.- 4 Preparation of Chitin Synthase.- 5 Product Characterization of Chitin Synthase.- 5.1 Chemical Identification.- 5.2 Biophysical Identification of Chitin.- 5.2.1 Fourier Transform Infrared Spectroscopy.- 5.2.2 X-Ray Diffraction Analysis.- 5.2.3 Electron Microscopy and Electron Diffraction Analysis.- 6 Polymerization and Crystallization.- 7 Fungal Chitin Synthase Genes.- 8 Morphogenetic Roles of Chitin Synthases.- 9 Conclusions.- References.- Analysis of Plant-Substratum Adhesives.- 1 Introduction.- 1.1 Principles of Adhesion.- 1.2 Cell-Substratum Adhesion.- 1.2.1 Higher Plant-Substratum Adhesion.- 1.2.2 Adhesion of Fungal Phytopathogens to a Plant Substratum.- 1.2.3 Algal-Substratum Adhesion.- 2 Case Studies of Cell-Substratum Adhesion.- 2.1 Substrate Adhesion by the Fucus Zygote.- 2.2 Adhesion of Conidiospores of the Plant Pathogenic Fungus, Nectria haematococca.- 3 Methods for the Analysis of Cell-Substratum Adhesives.- 3.1 Adhesion Systems and Assays.- 3.2 Identification of Adhesive Components.- 3.2.1 Isolation of Adhesion Mutants.- 3.2.2 Correlation of Temporal/Spatial Development with Adhesion.- 3.2.3 Experimental Perturbation of Adhesion.- 3.3 Analysis of Adhesive Components.- 3.3.1 Extraction and Purification.- 3.3.2 Assays of Isolated Compounds for Adhesive Activity.- 4 Conclusions.- References.- Biochemical, Immunological and Molecular Analyses of Extensin.- 1 Introduction.- 2 Biochemical Characterization of Extensin.- 2.1 Preparation of Walls.- 2.2 Protein Purification.- 2.3 Biochemical Characterization.- 3 Immunological Detection of Extensin.- 3.1 In Vivo Localization of Extensin.- 3.2 Western Blots and Tissue Prints.- 4 Molecular Characterization of Extensin.- 4.1 Isolation of Genes Encoding Extensin.- 4.2 Extensin Expression Studies.- 4.3 Extensin Promoter Fusions with Reporter Genes.- 4.4 Generation of Extensin Mutants.- 5 Summary.- References.- Analysis of Pectin Structure by HPAEC-PAD.- 1 Introduction.- 2 Pectin HPLC Separations.- 2.1 GPC.- 2.2 Ion-Exchange and Ion-Pair RP.- 2.3 HPAEC-PAD.- 3 Pectin Analysis in Ripening Peach Fruit.- 3.1 Melting- and Nonmelting-Flesh Peaches.- 3.2 HPAEC-PAD System.- 3.3 Sample Preparation.- 3.4 HPAEC-PAD of Redskin and Suncling Peach Pectin.- 4 Conclusions and Future Directions.- References.- Characterization of Oligosaccharides Derived from Plant Cell Wall Polysaccharides by On-Line High-Performance Anion-Exchange Chromatography Thermospray Mass Spectrometry.- 1 Introduction.- 2 Methods.- 2.1 Apparatus.- 2.2 Isolation of Oligosaccharides from Plant Cell Wall Material.- 3 HPAEC in Oligosaccharide Analysis.- 4 General Experimental Considerations Related to HPAEC-MS.- 4.1 Desalting by AMMS.- 4.2 Ionization of Oligosaccharides.- 4.3 Data Interpretation.- 5 Application of HPAEC-MS in Oligosaccharide Characterization.- 6 Conclusions and Perspectives.- References.- Analysis of Pectin Methyl Esterases.- 1 Introduction.- 2 Estimation and Detection of PME Activities.- 2.1 Detection.- 2.2 Estimation.- 3 PME Localization.- 4 PME Extraction and Purification.- 5 PME Properties.- 5.1 Physicochemical Properties.- 5.2 Enzymic Properties.- 5.2.1 Action Pattern.- 5.2.2 Influence of pH on PME Activity.- 5.2.3 Influence of Cations.- 5.3 Structures.- 6 Roles of PMEs.- 6.1 Plant Pathogens.- 6.2 Fruit Maturation.- 6.3 Cell Elongation.- 7 Conclusions and Perspectives.- References.- Probing the Subunit Composition and Topology of Plasma Membrane-Bound (1,3)-?-Glucan (Callose) Synthases.- 1 Introduction.- 2 Membrane Isolation, Enzyme Assay, and Solubilization.- 2.1 Isolation of Crude Membrane Fractions.- 2.2 Plasma Membrane Isolation.- 2.3 Membranes of Defined Sidedness: Inside Out and Right-Side Out Vesicles.- 2.4 Callose Synthase Assay.- 2.5 Callose Synthase Solubilization.- 3 Callose Synthase Topology, Purification, and Subunit Composition.- 3.1 Polypeptide Depletion.- 3.2 Vectorial Proteolysis.- 3.3 Callose Synthase Purification.- 3.3.1 Glycerol Gradient Centrifugation.- 3.3.2 Product Entrapment.- 4 Biochemical Characterization of Integral Plant Plasma Membrane Proteins.- 4.1 Characterization of Disulfide-Linked Aggregate Formation.- 4.2 Recovery of Hydrophobic Plant-Derived Membrane Proteins for Sequencing and Antibody Production.- 4.3 Antibody Characterization.- 4.3.1 Immunoblotting.- 4.3.2 Affinity Purification of Anti-PMIP27.- 5 Summary.- References.

Analysis of taste and aroma

1 Molecular Biology of Taste and Aroma Receptors: Implications for Taste and Aroma of Plant Products.- 2 Use of DNA Microarrays in the Identification of Genes Involved in Strawberry Flavor Formation.- 3 Testing for Taste and Flavour of Beer.- 4 Taste Evaluation for Peptides in Protein Hydrolysates from Soybean and Other Plants.- 5 Hop Aroma Extraction and Analysis.- 6 Olfactometry and Aroma Extract Dilution Analysis of Wines.- 7 Analysis of Volatile Components of Citrus Fruit Essential Oils.- 8 Aroma Volatiles in Fruits in Which Ethylene Production Is Depressed by Antisense Technology.- 9 Detection of Physiologically Active Flower Volatiles Using Gas Chromatography Coupled with Electroantennography.- 10 Analysis of Rhythmic Emission of Volatile Compounds of Rose Flowers.- 11 Odour Intensity Evaluation in GC-Olfactometry by Finger Span Method.- 12 Solid Phase Microextraction Application in GC/Olfactometry Dilution Analysis.- 13 RNA Gel Blot Analysis to Determine Gene Expression of Floral Scents.

Pollen DNA repair after treatment with the mutagens 4-nitroquinoline-1-oxide, ultraviolet and near-ultraviolet irradiation, and boron dependence of rapair

SummaryIrradiation of dry, mature pollen from Petunia hybrida with near-ultraviolet light from an erythemal-sunlamp gave rise to a repair-like, unscheduled DNA synthesis during the early stages of in vitro germination. Like that brought about by farultraviolet light from a germicidal lamp, this DNA synthesis is enhanced by hydroxyurea added to the germination medium, and reduced by photoreactivating light given after ultraviolet irradiation and before germination begins. It is concluded that pollen, often receiving considerable exposure to sunlight, has, in addition to the protection afforded by the ultraviolet filtering effect of yellow pigments, also the capacity to repair ultraviolet produced changes in DNA, by both photoreactivation and dark repair processes.Because mature Petunia pollen is arrested at the G2 stage of the cell cycle, germinating pollen provides us with a highly synchronous plant tissue with a very low background of DNA replicative synthesis suitable for sensitive measurement of DNA repair synthesis. Thus we have shown that 4-nitroquinoline-1-oxide, at concentrations greater than 0.001 mM, gives rise to an unscheduled DNA synthesis which is enhanced by hydroxyurea. Like that induced by ultraviolet radiation, the chemical mutagen brings about DNA repair only during the early stages of pollen germination, and further it has been possible to show that repair ceases at about the time that generative cell division and pollen tube elongation begins.Boron addition enhances both ultraviolet and 4-nitroquinoline-1-oxide induced repair synthesis. By delaying the chemical mutagen initiation of repair until after germination has begun, we have been able to show that boron is most beneficial during the first hour of germination. It is postulated that this is achieved through an as yet unknown effect of boron on the supply of precursors before pollen cell metabolism is fully committed to pollen tube synthesis later in the germination period.

Plant toxin analysis.

Analytical Methods for Phytotoxins.- Quantitative Assays of Phytotoxins Using Plant Protoplasts and Isolated Cells.- Determination of Host-Selective Toxins.- Evaluating the Phototoxicity and Photogenotoxicity of Plant Secondary Compounds.- Toxic Extracellular Enzymes.- Analysis of Toxic Extracellular Polysaccharides.- Immunological Analysis of Mycotoxins.- Multi-Toxin TLC Methods for Aflatoxins, Ochratoxin A, Zearalenone and Sterigmatocystin in Foods.- Isolation and Characterization of Elicitors.- Identification and Characterization of Suppressors.- Screening for Plant Antioxidants.- Methods for the Analysis of Isoprene Emission from Leaves.- Analysis of Ecotoxic Agents Using Pollen Tests.- The Determination of the Allelopathic Potential of Pollen and Nectar.- Determination of Cyanide and Cyanogenic Glycosides from Plants.

Phytate metabolism in Petunia pollen

Abstract Phytic acid has been detected in the anthers of young flower buds of Petunia hybrida , the amount increasing slowly as the flower develops until anther dehydration, when there was a more rapid increase in phytic acid content. In mature pollen, the phytic acid content was found to be 2.0 % by weight, of which 90 % was water soluble, while free myo -inositol was a relatively low 0.06 % by weight. Breakdown of phytic acid was initiated soon after pollen germination began, and its degradation products, myo -inositol and inorganic phosphate, were rapidly mobilized for phospholipid and pectin biosynthesis. Both are in high demand during pollen tube elongation. Utilization of myo -[2- 3 H]inositol for phospholipid biosynthesis was about five times that for pectin synthesis during the first few hours of pollen germination. The label in the phospholipid was identified as the myo -inositol moiety of phosphaltidylinositol, while the pectin material contained predominantly labelled arabinose, with smaller amounts of label in galacturonic acid, glucose and xylose. A chase experiment showed that the myo -inositol moiety of phosphatidylinositol was subject to a relatively rapid turnover, while the label in pectin was not. Labelling germinating pollen with [ 32 P]orthophosphate gave label in phosphatidic acid, phosphatidylinositol, phosphatidylethanolamine and phosphatidylcholine of the phospholipids. Phosphatidylinositol contained 30 % of this label initially, a proportion which declined to 10 % over longer periods of germination.

Phosphatidylinositol phospholipase C activity in pollen of Lilium longiflorum

Abstract Homogenates from pollen of Lilium longiflorum (cv. Arai) contain phosphatidylinositol phospholipase activity, which increased during germination. Analysis of radioactive products resulting from incubation of phosphatidylinositol, labelled in the myo -inositol, phosphate or glycerol moiety, showed that cleavage had only taken place between glycerol and phosphate. The activity is therefore of a phospholipase C-type (EC 3.1.4.10). It was stimulated by several divalent cations; Ca 2+ was the most effective. Zn 2+ , Cu 2+ and EDTA are inhibitory. The activity was found in both the cytosol and particulate fractions.

DNA repair in pollen: Range of mutagens inducing repair, effect of replication inhibitors and changes in thymidine nucleotide metabolism during repair

SummaryPollen of Petunia hybrida carry out DNA repair during the first two hours of germination when certain mutagens are included in the germination medium. This repair, detected readily as unscheduled DNA synthesis, since there is no replicative DNA synthesis in Petunia pollen, can be induced by the chemical mutagens N-methyl-N′-nitro-N-nitrosoguanidine, 4-nitroquinoline-1-oxide, azaserine and methyl methanesulphonate. These compounds are all considered to be capable of direct covalent interaction with DNA. Mutagens requiring metabolic activation before interaction with DNA did not induce DNA repair synthesis in pollen. The practice of solubilizing water-insoluble chemical mutagens with dimethyl sulphoxide did not prove practical, due to the extremely harmful effects of dimethyl sulphoxide on pollen. Pretreatment of pollen before germination with pure ether, however, had no harmful effect on either repair or pollen germination. Therefore water-insoluble, ether-soluble mutagens were tested by pretreatment of the pollen with mutagens in ether solution. By this means it was shown that the ‘direct-acting’ mutagen, diethyl sulphate, would also bring about unscheduled DNA synthesis in pollen, while 2-acetylaminofluorence and dimethyl-p-aminobenzene, both requiring metabolic activation, did not do so. Inhibitors of DNA replicative synthesis, hydroxyurea, azaserine, azauridine and fluorodeoxyuridine did not inhibit unscheduled DNA synthesis brought about by N-methyl-N′-nitro-N-nitrosoguanidine. On the contrary, these compounds stimulated repair synthesis to varying degrees, hydroxyurea having the greatest effect. Pollen uptake of 3H-thymidine and the amount of radioactive label subsequently appearing in dTMP and dTDP+dTTP was increased by 4-nitroquinoline-1-oxide. Partial inhibition of these increases and of 4-nitroquinoline-1-oxide induced repair synthesis by 3′,5′-cyclic AMP suggested that thymidine:AMP phosphotransferase rather than thymidine kinase was responsible for thymidine phosphorylation in pollen. Enzyme assays on pollen extracts confirmed this.

Increased RNA labelling in boron-deficient root-tip segments

Abstract The rate of incorporation of radioactive precursors into RNA of root-tip segments has been shown to increase during the early stages of boron deficiency in 6- to 8-day-old Phaseolus aureus seedlings. This effect is observed well before morphological changes occur, and before both the decrease in level of total RNA and increase in ribonuclease activity can be detected. The nucleotide pool in root tips was too small to measure directly on the rapidly growing seedlings, although it was easily measurable in the slower growing 12- to 15-day-old plants. The available indirect evidence suggests, however, that the early effect is not due to changes within the total nucleotide pool.