Correlation of cotylenol with the aglycone of fusicoccin

The stereostructure of cotylenol, the aglycone of the cotylenins, has been confirmed by chemical correlation with the aglycone of fusicoccin A.     

Biosynthesis of 1α,2α,3β-trihydroxy-p-menthane by Fusicoccum amygdali

Measurement of isotope ratios in 1α,2α,3β-trihydroxy-p-menthane, which has been biosynthesized in Fusicoccum amygdali from ³H- and ¹⁴C-labelled mevalonate and in its degradation product diosphenol indicates that: (a) four tritium atoms arising from [5-³H₂, 2-¹⁴C]MVA are retained, one more than suggested from the hydroxylation pattern, (b) menth-2-ene-1-ol is generated from an α-terpinyl cation through a 1,3-hydride shift and (c) trans-cleavage of an α-epoxide by hydrolysis gives 1α,2α,3β-trihydroxy-p-menthane.     

La Marana di Ciminiera (Foggia)

Summary

A «marana» of the Foggia Plain (Puglie) is a depression where water accumulates from the surrounding higher ground, and, very often, springs from the undersoil where the clay layer curves upwards. The soil is generally saline. It is not tillled but is grazed by herds of water-buffaloes. In the Marana di Ciminiera the auth. has found a mosaic of highly saline soils (with Salicornia fruticosa, Suaeda fruticosa, etc.), subsaline meadows (with Juncus acutus, Althaea officinalis, etc.), and fairly deep bogs, mostly drying up in summer (with Iris Pseudo-Acorus, Typha angustifolia, Phragmites communis, etc.).

A dense stand of Inula Helenium, one of Ligustrum vulgare, Lonicera etrusca, Crataegus Oxyacantha, Thalictrum flavum, Schoenus nigricans, and the general aspect of Lago della Contessa are described. Plants collected in the «marana» are listed.     

Effects of ophiobolin B on cell enlargement and H+/K+ exchange in maize coleoptile tissues

Ophiobolin B (OPH B), a sesterpene metabolite of Helminthosporium oryzae, inhibits proton extrusion from maize coleoptiles. Moreover OPH B counteracts the biological activity of fusicoccin (FC), another terpenoid toxin produced by Fusicoccum amygdali having a similar basic chemical structure: OPH B inhibits FC-promoted proton extrusion, potassium uptake and cell enlargement.The findings suggest that the effect of OPH B in stimulating electrolites, glucose and aminoacid leakage, reported in a previous paper, can be explained by the capacity of the toxin to inhibit proton extrusion.Abbreviations FC fusicoccin - OPH B ophiobolin B     

Accrescimento del pericarpo,seme, endosperma ed embrione in prunus Amygdalus stokes

Abstract

GROWTH OF PERICARP, SEED, ENDOSPERM, AND EMBRYO IN PRUNUS AMYGDALUS STOKES. — The fruits of an almond-tree growing at Bari were collected weekly from February 22nd to July 11th and on August 16th 1960. The material was kept in fixative; the growth of the various organs was studied both from a morphological and a quantitative point of view. Special attention was given to growth of the endosperm, especially during the nuclear stage and at the beginning of cellularisation (Figg. 1-14), and to the developement of the embryo until it reaches the « heart-shaped » stage (Figg. 15–22). From a quantitative point of view, the volume and main diameters of pericarp and seed, and whenever possible endosperm and embryo, were measured for each fruit. Most of the data are given in Tables I to V and Figg. 23 and 24.

If reference is made to the 3 phases of fruit growth established for other species (notably peaches and cherries), the main conclusions are that:

1. phase I (growth of pericarp, testa and nucellus) is clearly recognisable; it ends after the micropylar portion of the endosperm has become cellular and the embryo heart shaped;

2. phase II is also present: during this phase most of the growth of endosperm and embryo takes place; while the seed has reached its definite size at the end of phase I, the pericarp undergoes a period of greatly reduced growth;

3. two weeks after the beginning of phase II the pericarp seems to resume growth just for a very short period, judging at least by the weekly values of the ratio pericarp volume to seed volume (see Fig. 23); this seems to indicate the existence of a new phase, that is phase III, which in fleshy fruits of the genus Prunus corresponds to a much longer and important process of pericarp growth than in the almond;

4. as in the peaches and cherries therefore a crisis in pericarp growth occurs during the period of maximum rate of growth of the cellular endosperm and embryo;

5. the sequence: cellularisation of the endosperm, growth of endosperm and embryo, ceasing of seed growth, and reduction in pericarp growth is very clear, particularly if we take into account growth in length rather than in volume; both morphological and quantitative data would indicate the importance of the endosperm not only for the beginning of embryo development, but also for the control of pericarp growth.

     

A cytokinin from the culture filtrate of Pseudomonas syringae pv. savastanoi

The structure of a new cytokinin, isolated from the culture filtrate of Pseudomonas syringae pv. savastanoi, is assigned on the basis of spectroscopic data including its tetracetyl derivative and comparison with related adenine derivatives. It was identified as 6-(4-hydroxy-1,3-dimethylbut-trans-2-enylamino-9-β-D-ribofuranosyl)purine.     

Ultrastructure of the stylar canal cells ofCitrus limon (Rutaceae)

The ultrastructure of the canal cells and the canal filling substance ofCitrus limon have been studied. At maturity the canal cells are very rich in cytoplasm. Their inner tangential walls lining the canal are much thickened and formed by two layers: the outer corresponds to the original wall, the inner is formed by subsequent deposition of abundant materials of different origin. This thickening occurs at the same time as the filling of the stylar canal. Both events are paralleled by considerable dictyosomic activity, the formation of a large amount of rough endoplasmic reticulum, and the incorporation of small cytoplasmic masses into the cell wall, due to plasmalemma evaginations. — The material in the stylar canal has a heterogeneous ultrastructure aspect and consists of polysaccharides, proteins and lipids; it presumably provides nutrients for the growing pollen tubes.Research performed under CNR program Biology of Reproduction.     

Ricerche Sulla Flora Infestante Delle Culture in Italia

Summary

Studies on the weeds of cultivated land in italy

I. - bibliographical and methodological introduction

In the 1rst part of this paper the Author outlines the weed problem, discusses the meaning of the term “weed”, agrees with Korsmo (1930) in considering weeds as constituing a biological group characterised by certain adaptments to life.

After a short survey of the chief European and American books on weeds, he gives a more detailed account of the Italian literature which is not, the Author thinks, very rich on this subject.

In the 2nd part the Author discusses several aspects and some methodological questions of the study of weeds.

After dealing briefly with the floristic and quantitative analysis of weed floras, he goes on to outline the problem concerning the origin of the weed species of a given district; these can be considered as belonging to two main groups: local species which were present in that station before the soil was tilled, and exotic species introduced, often unwillingly, by man through his commercial and industrial activities. The line between the two groups is hard to draw, especially in countries of ancient civilization ad extensively cultivated, where in very few places the local flora has been left undisturbed. It is perhaps easier to distinguish the two main groups of species according to their geographic area of distribution and to the type of stations preferred within that area.

The study of weeds dissemination is strictly connected with the one of their origin.

The next main field of study is the ecological one: having shown the main ecological effects of agricultural technique, which also acts as a levelling agent for the vegetation of the earth, the Author agrees with E. P. Evans (1928) in stating that it is not easy “to draw any but very general conclusions” owing to the undeterminate and variable nature of the human biotic factors, which, together with natural ones, control weed growth. A great amount of research has been carried out on ecological problems a swell as sinecological and mainly agricultural ones concerning weeds. Examples are given, with reference to several Authors.

Lastly the Author stresses the importance of the biological study of weeds and describes at length the biological classification employed by Korsmo (1930), who devides weeds in three main groups, namely: “seed”, “stationary”, and “wandering” plants.

The bibliography is meant to give an useful list of references for the student, but is far from being complete, except as far as Italian literature is concerned.     

Binding of CD157 Protein to Fibronectin Regulates Cell Adhesion and Spreading

CD157/BST-1 behaves both as an ectoenzyme and signaling receptor and is an important regulator of leukocyte trafficking and ovarian cancer progression. However, the molecular interactions underpinning the role of CD157 in these processes remain obscure. The biological functions of CD157 and its partnership with members of the integrin family prompted us to assume the existence of a direct interaction between CD157 and an unknown component of the extracellular matrix. Using solid-phase binding assays and surface plasmon resonance analysis, we demonstrated that CD157 binds fibronectin with high affinity within its heparin-binding domains 1 and 2. Furthermore, we found that CD157 binds to other extracellular matrix proteins containing heparin-binding domains. Finally, we proved that the CD157-fibronectin interaction occurs with living cells, where it elicits CD157-mediated cell responses. Indeed, knockdown of CD157 in Met-5A mesothelial cells changed their morphology and cytoskeleton organization and attenuated the activation of intracellular signaling pathways triggered by fibronectin. This led to impaired cell spreading and adhesion to selected extracellular matrix proteins. Collectively, these findings indicate a central role of CD157 in cell-extracellular matrix interactions and make CD157 an attractive therapeutic target in inflammation and cancer.