I prodotti di demolizione dei nucleoproteidi quali stimolanti l'accrescimento della cellula vegetale

Riassunto

L'A. ha osservato la comparsa di sostanze stimolanti l'accrescimento della cellula vegetale in liquidi animali, ricchi di nucleoproteidi, in seguito a decomposizione batterica.

Nei liquidi attivi ha riscontrato oltre eteroauxina abbondante acido urico.

L'attività dell'acido urico sintetico e l'attività dei liquidi sperimentati anche dopo semplice digestione enzimatica, suggeriscono l'ipotesi che i composti (amino e sopratutto ossi-purinici) derivanti dal metabolismo nucleo-proteico possano avere valore come sostanze di accrescimento.     

Identificazione di alcuni lieviti isolati da pasta di legno

Summary Several species of yeasts isolated from wood-pulp used for paper manufacture were studied. A few species were previously found also as parasitic of men; one (Mycotorula mucinosa) is new for the science.     

I prodotti di demolizione dei nucleoproteidi quali stimolanti la divisione della cellula vegetale

Riassunto

L'A. ha studiato l'azione di ammonio lattato, asparagina, nucleinato sodico, adenina, guanina, ipoxantina, xantina ed acido urico sulla moltiplicazione cellulare di Mucor, Saccharomyces, Clorella, formazioni callose di carote, germinazione di semi di Cattleya. Di tutte queste sostanze si sono rivelate attive, per azione stimolante, soltanto i prodotti a più netto significato catabolico : xantina ed acido urico.

Rimane quindi confermata l'ipotesi che gli stessi prodotti di scadimento del metabolismo nucle-proteico possano avere valore di sostanze regolatrici non solo della distensione, ma anche della motiplicazione cellulare ed in base a questo reprto si prospetta l'ipotesi che il meccanismo stimolazione della distensione e della moltiplicazione cellulare sia fondamentalmente lo stesso.     

Studio preliminare sulla tipologia della vegetazione sommersa del Canale di Sicilia e isole vicine

Abstract

Preliminary studies on the marine phythobenthic communities in the Straits of Sicily and adjacent islands. — The results of algological researches carried out by the Gruppo di Algologia of the S.B.I. in the Straits of Sicily and adjacent islands are reported. 288 species have been collected, 275 of which have been identified: 160 were Rhodophyta, 62 Phaeophyta, 32 Chlorophyta, 16 Cyanophyta and 2 Angiospermae. The vegetational research leads to the following conclusions: 1 - the harbour areas (Pantelleria, Malta: loc. 1 and 11) show a nitrophile vegetation, particulary near La Valletta where an almost pure population of Pterocladia pinnata is found; 2 - there are important biogeographical differences between Pelagie islands (Lampedusa, Linosa) and Pantelleria. In fact the former ones have an algal flora composed mostly of eastern mediterranean species, whilst the latter shows strong affinities with the north-african basin, as is demonstrated by the rich well developed belt of Cystoseira sedoides; 3 - several species of atlantic origin, such as Callophyllis laciniata, Peyssonnelia coriacea, P. inamoena and Castagnea chordariaeformis, have been found on the banks (loc. 3, 6, 7).     

Effetti del trattamento In Vivo con auxlna di internodi di pisello sulla fosforilazione ossidativa dei mitocondri In Vitro

Abstract

EFFECT OF TREATMENT WITH IAA OF PEA INTERNODE SECTIONS ON THE OXIDATIVE PHOSPHORYLATION OF THEIR MITOCHONDRIA. — It was previously shown that auxin treatment raises the level of ATP in pea stem sections, under the conditions where the hormone stimulates growth (MARRé AND FORTI). It is also known that under the same conditions auxin stimulates oxygen uptake (MARRé, FORTI e ARRIGONI; MARRÉ and FORTI), and that the auxin induced respiration is most probably mediated by cytochrome oxidase (MARRÉ, FORTI and GAUR).

However, auxin has no effect when added to isolated mitochondria. In this paper, the effect of auxin treatment of the tissue on the activity of mitochondria isolated after the hormone treatment has been studied. It has been found that oxidative phosphorylation of mitochondria from the auxin treated pea stem sections is 13% higher than that of controi sections. The auxin effect is significant at 96% probabilities. There is no effect of the hormone on the P/O ratio.     

Aspetti Enzimatici Della Maturazione e Germinazione dei Semi di Ricino

Abstract

Enzyme levels during ripening and germination of castor bean seeds. — During the development of the endosperm of castor bean seeds two distinct phases can be recognized: pre-maturation and germination. The former is characterized, metabolically, by the rapid conversion of carbohydrates into lipids, and storage proteins. The latter is characterized by the reconversion of these storage materials into sugars. Both these processes are dependent upon the activity of the glycolytic pathway; for this reason the behaviour of some enzymes of this pathway and, in general, of the carbohydrate metabolism have been studied during the two phases. The changes (during the evolution of the seeds) of the following enzymes have been studied:

Gl-6-P-dehydrogenase, 6-P-gluconate dehydrogenase, P-glucomutase, Hexokinase Hexoseisomerase, Aldolase, alcaline and acid Phosphatase, Pyrophosphatase and ATP-ase.

All these activities have been measured in the 20.000 × g supernatant fraction of cell homogenates.

The results show that all the enzymes activities measured increase rapidly during the period of accumulation of storage materials. In the following period all of these activities decrease until the stage of ripeness of the seed. During the first few days of germination the activities increase again rapidly. A particular behaviour is the one of Fr-1-6-P-phosphatase (the enzyme cleaving the phosphate bond in C ¹ position). This enzyme reaches during germination a level much higher than the maximal observed during the ripening process. This might be an important fact correlated with the inversion of the glycolytic reactions during germination.     

Effetto della rimozione dei fiori sulla crescita delle piante e sul contenuto in leghemoglobina dei tubercoli radicali di pisello e fava

Abstract

Observations on vegetative growth and leghemoglobin contents of root nodules of pea and bean plants after flower bud removal. — These studies found their origin in the papers by MATTIROLO (1899) on the effect of the removal of flowers as they formed in bean plants; he observed that deflowering resulted in extraordinary plant growth, stem branching and flower buds formation as well as in a delayed root nodule senescence. In the light of modern knowledge of the leghemoglobin role in symbiotic nitrogen fixation, the aim of the present research was to ascertain any possible relation between flower bud removal and haeme pigment contents in the root nodules. The experiments were carried out during two growing seasons (1966 and 1970) using Vicia faba L. cv. Regina and Pisum sativum L. cv. Senatore during 1966 and cv. Vittoria in 1970. In both control and test plants the seasonal trends of average plant height, fresh and dry weight of vegetative portions, fresh and dry weight of root system, fresh weight of nodules, root nodule leghemoglobin concentration and total leghemoglobin content per plant, were determined. The data obtained are quoted in Table 2 and reported in Figures 1, 2, and 3. The removal of flower buds caused in both species: an increased plant growth, a marked stem branching, a longer blooming period, an increased flower number, an increased root nodule number and a certain delay in root nodule reabsorption. Deflowering did not significantly extend — at least in the species studied — life span (senescence was delayed only of one week). On the basis of these and of other Authors' results, we conclude that deflowering may actually delay senescence; the size of this delay, however, depends on the plant species considered and is fairly negligible both in pea and bean. The different effects of deflowering and of preventing floral induction on life span extension, are discussed, and these facts lead to consider floral induction as the onset of a chain of processes leading annual plants toward senescence in a more or less delayable, but definitive way. After having stressed the generally accepted importance of leghemoglobin concentration as an index of nodule nitrogen fixing ability, a correlation between biomass increase of test plants and number and total weight increase of root nodules, is put in evidence. No correlation between test plant biomass and the leghemoglobin concentration in root nodules, was however observed. Leghemoglobin concentration in root nodules is known to change in connection with various factors depending either on host plants and on Rhizobium strains and also in connection with several environmental conditions. Any prevented flower onset (ROPONEN and VIRTANEN, 1968) and deflowering (our data) however exerted no significant influence. The effects of flower bud removal were therefore the following: increased stem, leaf and root weights and increased root nodule number; no difference between control and test plants was however observed as regards size and leghemoglobin concentration of root nodules and hence probably no difference as regards their nitrogen fixing ability.     

Osservazioni istoanatomiche e sperimentali sulla innervazione dell'esofago di alcuni mammiferi

Zusammenfassung Die Versuche wurden ausgeführt, um weitere Beiträge zur Morphologie der Vagusfasern in der Speiseröhre zu liefern und zwecks Analyse der neurosynaptischen Verhältnisse zwischen Vagus und Sympathicus. In Speiseröhren von kleinen Säugetieren gelang es, die Verzweigungen des Vagus bis zu deren Endausbreitung zu verfolgen. Es wurden Kontrollen mit morpho-experimentellen Versuchen von Vagotomie ausgeführt.In den Ästen des Vagus der Speiseröhre befinden sich: Parasympathische präganglionäre Fasern, gemischte Fasern (heteromorphe: präganglionäre und motorische Fasern), sensitive Fasern und sehr dünne Fasern des Orthosympathicus.Viele präganglionäre Fasern breiten sich in mehr oder weniger ausgedehnten retikulären Bildungen (präneuronodales Retikulum) aus, bevor sie zu dem Ganglion, für welches sie bestimmt sind, gelangen. Im Ganglion platten sich einige präganglionäre Fasern ab und werden blattförmig. Andere wieder verbreitern sich zu fibrillären Bildungen retikulärer Struktur. In Präparaten mit feinerer Imprägnation bilden die präganglionären Fasern des Vagus keine synaptischen, perizellulären-Apparate des klassischen Typus sondern breiten sich in ein überaus dünnes Retikulum (terminalreticolo vagale pregangliare) im Ganglion aus.Dieses Retikulum umhüllt nicht bloß die nervösen Zellen, sondern breitet sich über alle Teile des Ganglions aus. Die als motorisch erkennbaren Fasern des Vagus liefern alle motorischen Endigungen, die traubenförmigen einbegriffen. Ich habe besondere, charakteristische, motorische, knäuelförmige Endapparate bemerkt. Diese und auch jene als Endbüschel (Lawrentjew) benannten Bildungen können ultraterminalen Fasern, die sich in gewöhnlichen Plättchen ausdehnen, den Ursprung geben oder das Ende traubenförmiger Ausdehnungen darstellen.Die gemischten Fasern (heteromorphe: präganglionäre und motorische) sind in überwiegender Weise motorische Vagusfasern, die einen kollateralen Ast liefern, der sich entweder auf die alleinstehenden Ganglienzellen ausdehnt oder im Ganglion sich mit den intraganglionären Fasern vermischt.Die rezeptorischen Fasern des Vagus bilden die Schlingenterritorien (Stöhr, Harting) oder die knäuelförmigen Bildungen von Greving. Manchmal schließen sich den sensitiven Vagusfasern zahlreiche, sehr dünne, wahrscheinlich metasympathische Fasern an.Ein Teil des metasympathischen Anteiles bildet einen Komplex von Fasern oder kleinen Strängen, welche die präganglionären, motorischen, gemischten und sensitiven Bestandteile des Vagus begleiten; diese metasympathischen Fasern bilden insbesondere in der Nähe der Ganglien sehr feine Retikula in enger Verbindung mit den parasympathischen Elementen.Im distalen Teil der Speiseröhre ist der sympathische Bestandteil überwiegend; es finden sich hier kleine Ringe oder kleine knöpfchenartige Bildungen, die von den motorischen Fasern des Vagus ausgehen, an dem glatten Muskelgewebe vor, es finden sich außerdem einige Nervenzellen mit perizellulären Apparaten, die jedoch von den obengenannten präganglionären Vagusendigungen verschieden und wahrscheinlich sympathischer Natur sind. Die anatomischen Eigenheiten im distalen Teil der Speiseröhre stellen wahrscheinlich die morphologische Grundlage für den Automatismus jenes Teiles der Speiseröhre dar.     

Azione della Cinetina sulla Degradazione della Clorofilla in Foglie di Orzo Irradiate

Abstract

The effects of kinetin on chlorophyll breakdown in irradiated barley leaves. — Kinetin is shown to inhibit the breakdown of chlorophyll in isolated barley leaves. Moreover the kinetin is shown to inhibit, even if with lower effect, the chlorophyll breakdown in irradiated barley leaves. This possible correlation of these observations, with kinetin promoted protein synthesis is suggested.     

contributo alla conoscenza della flora microbica di alcuni formaggi italiani

Zusammenfassung Es wurden aus einigen Sorten italienischer Weichkäse Hefen isoliert und untersucht.In der vorliegenden Note sind nur einige sporogene Formen beschrieben, Zygosaccharomyces casei sp. n., Saccharomyces fragilis Joergensen, S. cartilaginosus Lindner und eine neue Varietät dieser Form, S. cartilaginosus var. italica var. n. genannt.Diese Hefen wurden auch auf ihre Resistenz der Temperatur, der Milchsäure und dem Kochsalz gegenüber untersucht.     

Ulteriori osservazioni ed esperienze sulla monoginia dei Formicidi: Saggio di un'analisi del comportamento inLeptothorax exilis Em.

Riassunto L'autore riassume le attuali conoscenze sulla monoginia dei formicidi e discute dell'opportunità di adottare questo termine in luogo di altri preesistenti nella letteratura. Vengono inoltre riferite alcune esperienze in base alle quali è lecito concludere che ilLeptothorax exilis Em. è specie monogina e che questa condizione, nel caso di fusione tra colonie giovani, è assicurata dall'intervento delle operaie. L'aggressività delle operaie nei confronti delle regine estranee non può essere spiegata solo in base alla diversità dell'odore caratteristico del formicaio ed è in stretta correlazione con la presenza della regina madre od anche solo del suo cadavere. Vengono inoltre schematizzati i diversi metodi con cui le formiche si assicurano la monoginia della colonia.

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Summary The autor summarizes present knowledge about the monogyny of Formicidae and considers the appropriateness of this term in preference to those hitherto in use. The A. also reports some experiences that lead to the conclusion thatLeptothorax exilis Em. is a monogynic species, a condition which in case of the fusion of young colonies is assured by the intervention of the workers. The aggressive behaviour of the workers toward foreign queens cannot be explained solely by the diversity of the odor characteristic of each colony. It is also in direct relationship with the presence of the queen mother or even just her corpse. The A. outlines the various methods by which ants assure the monogyny of the colony.

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Résumé L'auteur résume les connaissances actuelles sur la monogynie des fourmis et discute l'opportunité d'adopter ce terme au lieu des autres préexistants dans la littérature. Il rapporte en outre quelques expériences qui lui permettent de conclure queLeptothorax exilis Em. est une espèce monogyne et que cette condition, en cas de fusion entre jeunes colonies, est assurée par l'intervention des ouvrières. L'hostilité des ouvrières contre les reines étrangères ne peut pas être expliquée par la seule diversité de l'odeur caractéristique du nid et est strictement liée à la présence de la reine mère ou même seulement à celle de morceaux de son cadavre. On fournit enfin un schéma des différentes méthodes avec lesquelles les fourmis assurent la monogynie de la colonie.

     

L'impostazione dello studio di alcuni funghi parassiti e patogeni dell'uomo (A proposito di una pubblicazione su Histoplasma)

Summary A recent paper on Histoplasma affinities with the Genera Sepedonium and others is briefly examined. The outstanding objections is the unilateral point of view in systematic study of highly parasitic, pathogenic Fungi, as observed only during the saprophytic stage (in culture media). The sterility of this method of study is clearly demonstrated, e.g., by comparative observations of the morphology of Coccidioides in vitro and in vivo.

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Zusammenfassung Eine kurze Prüfung einer neuerschienenen Veröffentlichung über Histoplasma, welche trotz der schönen Beobachtungen, keine weiteren Vorschritt den vorgangenen Kenntnissen liefert, gibt die Veranlassung zu bemerken, dass die für den Menschen hoch spezialisierten Pilze, welche in vivo" ihre grössten Tätigkeiten besitzen, müssen auch auf die lebenden Geweben empfänglicher Tiere untersucht werden, sonst wird die Beobachtung bei der kulturellen saprophytischen Phase den systematisch weniger bedeutenden Formen begrenzt.