F.R. Whatley

From extracellular to intracellular: the establishment of mitochondria and chloroplasts.

Paracoccus and Rhodopseudomonas are unusual among bacteria in having a majority of the biochemical features of mitochondria; blue-green algae have many of the features of chloroplasts. The theory of serial endo-symbiosis proposes that a primitive eukaryote successively took up bacteria and blue-green algae to yield mitochondria and chloroplasts respectively. Possible characteristics of transitional forms are indicated both by the primitive amoeba, Pelomyxa, which lacks mitochondria but contains a permanent population of endosymbiotic bacteria, and by several anomalous eukaryotic algae, e. g. Cyanophora, which contain cyanelles instead of chloroplasts. Blue-green algae appear to be obvious precursors of red algal chloroplasts but the ancestry of other chloroplasts is less certain, though the epizoic symbiont, Prochloron, may resemble the ancestral green algal chloroplast. We speculate that the chloroplasts of the remaining algae may have had a eukaryotic origin. The evolution of organelles from endosymbiotic precursors would involve their integration with the host cell biochemically, structurally and numerically.

The analysis of bud exudate of Populus x euramericana, and of propolis, by gas chromatography-mass spectrometry

Propolis and bud exudate of Populus x euramericana have been analysed by high-resolution gas chromatography–mass spectrometry; 104 compounds have been identified, including 26 not previously identified in propolis or bud exudate. The compounds identified in propolis are derived from three sources: plant exudate collected by bees, wax secreted by bees, and materials such as sugars, which are probably introduced accidentally either during propolis manufacture or during subsequent passage of bees over the propolis. Previous observations that bees use bud exudate from Populus as a primary source for propolis manufacture are confirmed.

4,4′-Dihydroxytruxillic acid as a component of cell walls of Lolium multiflorum

Abstract 4,4′-Dihydroxytruxillic acid was released from the cell walls of Lolium multiflorum by treatment with sodium hydroxide. Combined gas chromatography-mass spectrometry indicated that other similar dimers, probably resulting from the photodimerization of p-coumaric acid or ferulic acid, were also released from the cell walls. The possible role of the dimers in cross-linking cell wall heteroxylans is discussed.

Flavonoid aglycones identified by gas chromatography-mass spectrometry in bud exudate of Populus balsamifera

We here identify five chalcones and six dihydrochalcones. Of these, three chalcones and five dihydrochalcones have not, we believe, been previously identified in Populus bud exudate. The technique of GC-MS has not been previously applied successfully to the resolution of such a complex mixture

Analysis of phenolics of Populus trichocarpa bud exudate by GC-MS

Abstract Analysis by GC-MS identified 57 phenolic compounds in the bud exudate of Populus trichocarpa. Of these 11 have not been previously identified in poplar bud exudate. The bulk of the exudate was composed of acetophenones, substituted benzoic acids and their esters, cinnamic acid and its esters, dihydrochalcones, terpenoids and hydrocarbons.

Resolution of complex mixtures of phenolics in poplar bud exudate by analysis of gas chromatography-mass spectrometry data.

Abstract The complex mixture of phenolic compounds which is present in the bud exudate of many poplars may be resolved by single ion reconstructions of gas chromatography-mass spectrometry data. The prominent [M − 15]+ ions of the trimethylsilyl derivatives of chalcones, dihydrochalcones, flavones and flavanones render them particularly suitable for location by single ion reconstructions.

Analysis of phenolics in the bud exudates of Populus deltoides, P. fremontii, P. sargentii and P. Wislizenii by GC-MS

Abstract Analysis of bud exudates of Populus deltoides , P. fremontii , P. sargentii and P. wislizenii (Section Aigeiros ) by GC-MS identified a total of 78 components, of which 58 were phenolics. The composition of the bud exudate of all four species was highly similar, the most abundant components being pinocembrin and its chalcone, pinobanksin and its 3-methyl ether, pinobanksin-3-acetate and galangin.

Analysis of phenolics of bud exudate of Populus sieboldii by GC-MS

Abstract Analysis by GC-MS separated 50 components of bud exudate from P. sieboldii (Section Leuce ) of which 36 were phenolics. The bulk of the bud exudate (66.7%) was composed of the flavanone naringenin and its methyl ethers sakuranetin and isosakuranetin, together with their corresponding chalcones. These flavanones are minor components (

The metabolism of [1-13C]-glucose by Paracoccus denitrificans, investigated by gas chromatography-mass spectrometry

The metabolism of Paracoccus denitrificans, grown on [1-13C]-glucose as the sole carbon source, was investigated by using gas chromatographymass spectrometry and metabolic profiling. The distribution of label in a wide range of metabolites (42 in total) showed that the EmbdenMeyerhoff pathway did not operate in vivo whereas both the EntnerDoudoroff and pentose phosphate pathways were operative under the specified growth conditions. It was calculated that 31% of the [1-13C]-glucose was metabolized by the Entner-Doudoroff pathway and 69% by the pentose phosphate pathway.

Phenolic analysis of bud exudate of Populus lasiocarpa by GC/MS

Abstract The summer bud exudate of two plants of P. lasiocarpa analysed by GC/MS lacked the flavonoid aglycones and substituted benzoic and phenolic acid esters characteristic of other poplar species. Other compounds, such as syringaldehyde, syringic acid and shikimic acid, not previously identified in bud exudate of other poplar species were found, as were catechin, catechol, quinic acid and salicin, compounds not normally present in poplar bud exudate. The exudates from the two sources differed considerably in detailed composition.