Morpho-colorimetric characterization by image analysis to identify diaspores of wild plant species

Digital images of ex situ germplasm stored in the Sardinian Germplasm Bank (BG-SAR) were used for the application of image analysis techniques at the Stazione Sperimentale di Granicoltura per la Sicilia. The analysed accessions refer to 148 taxonomic units belonging to 102 genera and 47 families, typical of the Sardinian flora, and of the Mediterranean basin in general.The images of diaspores were acquired by a flatbed scanner and elaborated with a macro specially developed for the morphometric and colorimetric measurements. This method allowed carrying out a database for the characterization of autochthonous germplasm in entry to the bank and the realization of statistic classifiers for the discrimination of genera and species within the following families: Apiaceae, Boraginaceae, Caryophyllaceae, Cistaceae, Fabaceae and Scrophulariaceae. Such classifiers, based on the linear discriminant analysis (LDA) technique and checked by cross-validation, showed a performance included between 74.3% and 96.4%.In addition, for the genus Astragalus, it was possible to elaborate a classifier able to identify very similar taxa of a species complex, obtaining a performance between 83.7% and 100%. Such analysis proved the validity of the methodology also from the taxonomic point of view.Suggestions for subsequent methodological progress, which could offer applications in other research issues, such as ecological analysis, soil seed bank and archaeological botany are proposed.     

Intrauterine programming of ageing

Ageing is an unavoidable corollary to being alive; the most intuitive interpretation of ageing being that it is the consequence of progressive body degeneration. In agreement with this, current models propose that ageing occurs through a stepwise accumulation of DNA damage, which ultimately limits the regenerative capacity of tissues. On the other hand, there is increasing evidence that fetal distress can influence the development of disease in adult life, a phenomenon known as ‘intrauterine programming’. The extent to which an intrauterine exposure to DNA damage can compromise lifespan remains unclear. My group has recently generated a murine model of a human syndrome linked to defective DNA repair and observed that these animals age prematurely, but the accumulation of DNA damage is restricted mostly to the embryonic period. Here, I discuss the implications of this finding and propose that ageing can be influenced by fetal distress.     

Conformation of 4-thio-l-lyxono-1,4-lactone in solution and in the crystalline state

The conformation in ²H₂O of 4-thio-l-lyxono-1,4-lactone (1) was studied by nuclear magnetic resonance spectroscopy, by means of homonuclear (J_1H,1H) and heteronuclear (J_1H,13C) coupling constants. The couplings were directly measured by a two-dimensional heteronucleus-coupled ω₁ hetero-half-filtered proton-proton correlation (HETLOC) experiment, which does not require ¹³C isotopic enrichment. In solution, the thiolactone ring of 1 adopts preferentially the E₃ conformation, and its hydroxymethyl group populates mainly the gt rotamer. The X-ray diffraction data of a single crystal of 1 indicates that also in the solid state the thiolactone ring adopts an E₃ conformation, with a puckering somewhat larger than that observed for aldono-1,4-lactones and furanose rings. The molecules are linked by hydrogen bonds, which form chains. Particularly, O-5 is fully engaged as donor and acceptor in hydrogen bonding and the rotameric conformation of the hydroxymethyl group of 1 is fixed in the tg form.     

ISOLATION AND PROPERTIES OF A CELL FROM LIVER CHARACTERIZED BY LIPID-RICH PARTICLES

A cell has been isolated from explanted rabbit liver which contains, during all phases of its growth in culture, hundreds of lipid-rich particles with a distinct limiting membrane. The cell grows logarithmically with a generation time of 19 to 20 hours and during mitosis the particles are distributed between the daughter cells. Associated with the particles is the high total lipid content of the rabbit liver cell as compared with a rat liver cell, which contains few, if any, lipid-rich particles. This difference in lipid content between the two cells is due primarily to an increase in the triglyceride fraction, in contradistinction to small differences in the polar lipid and sterol ester fractions. The lipid-rich particles have been isolated and found to contain 90 per cent triglyceride on a dry weight basis. The "genetic" factors responsible for the high concentration of lipid-rich particles and triglycerides in the rabbit liver cell require for their full expression one or more factors which are present in much higher effective concentrations in rabbit serum than in horse serum. The hypothesis is advanced that the lipid-rich particles represent a normal state of the non-structural cell lipid. A procedure is described for the quantitative isolation of the lipid of cultured cells.     

Ultraviolet light sensitivity of carotene-and cytochrome-c-accumulating strains of the smut fungusUstilago violacea

White, pink, orange, and yellow strains ofUstilago violacea containing high and low levels of cytochrome c and various carotenes were exposed to ultraviolet light. The survival curves for all strains were of exponential decay form, but the carotene-accumulating strains were generally more resistant to UV than those strains with no carotenes at all. The UV exposure time leading to 90% loss in viability, LD₉₀, was quantitatively related to the carotene content in the form of a power function, where LD₉₀ increased as the fifth root of the total carotene content per cell. We also determined that the ratio of total carotenes to total cytochrome c per cell was quantitatively related to the rate of viability loss during UV exposure.     

Bicyclo[3,2,1]octanoid,neolignans from Aniba simulans

Six bicyclo[3,2,1]octanoid neolignans, isolated from the benzene extract of Aniba simulans Allen (Lauraceae) trunk wood, are shown to derive from two basic structures: 1-allyl-8-hydroxy-6-(3′-methoxy-4′,5′-methylenedioxyphenyl)-7-methyl-3-oxobicyclo[3,2,1]octane, substituted by 4-hydroxy, 4-hydroxy-5-methoxy, 4-methoxy or 4,5-dimethoxy groups; and 1-allyl-8-hydroxy-6-(3′-methoxy-4′,5′-methylenedioxyphenyl)-7-methyl-4-oxobicyclo[3,2,1]oct-2-ene, substituted by 3-hydroxy or 3-hydroxy-5-methoxy groups. The structural proposals are based on spectral data, interconversions synthesis of a derivative from the known (2R,3S,3aS)-3a-allyl-5-methoxy-2-(3′-methoxy,4′,5′-methylenedioxyphenyl)-3-methyl-2,3,3a,6-tetrahydro-6-oxobenzofuran.