L'Evoluzione Dei Cloroplasti Durante L'Inverdimento Sperimentale Di Frammenti di Tuberi di Topinambour (Helianthus Tuberosus)

Abstract

Lembotropis emeriflorus (Rchb.) Skali?ka in the Carnian Alps too.—Lembotropis (=Cytisus) emeriflorus, endemic species between the lakes of Lugano and Como, occurs also in the Southern Carnian Alps, where it grows either on gravelly habitats or on rocky slopes or under Austrian pine woods of the mountain zone. After this discovery its distributional pattern is now a typical bicentric one.     

Effetto Dell'attinomicina Sulla Crescita di Alcune Specie di Alghe

Abstract

Action of Actinomycin on the growth of Algae. — Actinomycin C inhibits the growth of two strains of Euglena gracilis, of Chlorella vulgaris, of Prototheca zopfii and of Scenedesmus sp. The growth inhibitory effect is evident on both autotrophically and heterotrophically grown cultures. DNA extracted from C. vulgaris appears to form a complex with Actinomycin C similar to that observed in the case of other organisms.     

Effetto della Presenza di Zuccheri Sull'attivita Esochinasica in Cotiledoni Germinanti di Ricino

Abstract

The effects of sugars on the development of hexokinase and fructokinase activities in isolated cotyledons from germinating castor bean seeds. — The possibility of an inductive effect of hexose concentration on the rate of synthesis of enzymes involved in the phosphorylation of sugars has been investigated. Cotyledons were removed from castor bean seeds germinated 48 h at 27 °C in the dark, and incubated 12 h in water or in 0,05–0,1 M glucose or fructose. The activities of hexokinase and of fructokinase (determined spectrophotometrically in the soluble fraction from cell free extracts) was found to increase, upon incubation, at a rate more than 100% higher for the cotyledons incubated in the presence of sugars than for those in water. The results suggest some specificity of the effect of fructose on fructokinase and of glucose on hexokinase. « Insoluble » hexokinase was not affected by the sugars. Protein synthesis inhibitors such as actinomycin D and puromycin inhibited any increase of kinase activities in the isolated cotyledons.     

Saggio di inoculazioni incrociate di funghi patogeni tra animali e piante

Summary Common frogs (Rana edulis) were inoculated intraperitoneally with the following fungi: 1) pathogenic for man and animals:Coccidioides immitis, Gilchristia dermatitidis, Paracoccidioides brasiliensis, Phialophora verrucosa andSporotrichum beurmanni; 2) pathogenic for man and plants:Sporotrichum poae; 3) pathogenic for plants:Botrytis cinerea. The fungi of the group 1) (and, to a lesser extent, the group 2) produced a localized granuloma, without (or almost without) dissemination, with a reduced, aspecific reaction, chiefly in the gastro-duodenal plica. The species of the group 3) is not pathogenic at all.On the contrary, for broad bean young plants (and, to a lesser extent, castor bean plants) the fungi of the group 1) were not pathogenic, while the fungus of the group 3) was fully pathogenic.S. poae appears to be of moderate pathogenicity; less pathogenic has beenS. beurmanni.

---

---

Un riassunto parziale di queste prove è stato presentato dai due Autori al Third International Congress for Microbiology, New York, 2–9 September 1939 (Sect. VI, Paper No. 5) e pubblicato nel 1940 (Redaelli P., Ciferri R. eBaldacci Blastomycosis, Sporotrichosis and Coccidioidal granuloma on animals and plants. Mycopathologia,II, 322–326 1940. Le esperienze furono quindi proseguite dai due Autori seniores, secondo una più vasta scala di ricerche, sinchè il sopraggiungere della guerra e le difficoltà di lavoro inerenti obbligarono a sospenderle. Ancora nell'intento di onorare la memoria del compianto amico e collaboratore Prof.P. Redaelli, ci decidiamo a dare alla luce queste note, ora pubblicate in esteso, completate con le prove eseguite dopo la presentazione della nota suddetta. R. C.     

Effetto dell'Irraggiamento X sulla Biosintesi degli Amminoacidi in Piante di Orzo

Abstract

The effects of irradiation on aminoacids biosynthesis in barley. — The effect of radiations on the biosynthesis of aminoacids in barley has been studied. Seeds have been irradiated with X-tays of 7.5 and seedlings with 7.5, 15 and 30 Kr. After 6–7 days of growth the control and irradiated seedlings, and the seedlings from control and irradiated seeds, have been supplied with 10–100 μC of C¹⁴O₂ in a closed chamber for 44–42 hours. The material was extracted with hot ethanol (85%–80% and 40%). Total radioactivity and the radioactivity of the basic fraction, eluted with HCl from Dowex 50, X-8′ (200–400 mesh, H^?) have been measured. It was observed that radiations increase the radioactivity of the aminoacid fraction, both in leaves and roots. A correlation between the decrease of fresh weight and increase of aminoacids radioactivity was shown. A possible explanation might be visualized in terms of the inhibition of growth and protein synthesis by radiations.     

Correlazioni tra organi di senso e centri nervosi in via di sviluppo

Zusammenfassung In FÄllen, wo beiLoligo-Embryonen infolge der Einwirkung von Lithiumchlorid die Augenentwicklung asymmetrisch gehemmt ist, entspricht der gehemmten Entwicklung der Augen immer eine solche des zugehörigen Augenganglions. In seltenen FÄllen kann man auch beobachten, da\ zu einem gehemmten Ganglion ein normales Auge gehört, aber niemals das umgekehrte. Diese Korrelationen sind nicht durch Lagebeziehungen bestimmt. Bringt man diese Tatsachen mit denen zusammen, die über diese VerhÄltnisse bei Vertebraten bekannt sind, so kommt man zu dem Schlusse, da\ höchstwahrscheinlich das Cephalopodenauge die Entwicklung des zugehörigen Augenganglions leitet.     

Morphogenesis in Helianthus Tuberosus: Genotypic Influence and Increased Totipotency in Previously Regenerated Plants

Leaf tissues of 38 genotypes, derived from four accessions, of the hexaploid species Helianthus tuberosus (2n=6x=102) responded to growth regulators (BA, NAA) chiefly by forming callus, while aventitious organogenesis or somatic embryogenesis were induced occasionally. A remarkable regeneration frequency (about 30 %) was achieved only from leaves of genotype HTPI-15. Explants of many regenerated plants of HTPI-15 subjected to a second culture cycle in vitro displayed a high morphogenetic potential (regeneration frequency > 90 %). White globular structures were initiated on the adaxial surface of these leaves without a callus phase. Somatic embryogenesis was asynchronous and embryoids, of different developmental stage, were simultaneously detected on each explant. Although many embryos developed single or malformed cotyledons or germinated precocciously, without the differentiation of a complete root system, phenotypically normal plants were regenerated after rooting on regulator-free half-strength MS medium. This revised version was published online in July 2006 with corrections to the Cover Date.     

Effetto della cocliobolina sul trasporto attivo del sodio nella pelle isolata di Rana esculenta

Abstract

INFLUENCE OF COCHLIOBOLIN ON ACTIVE TRANSFER OF SODIUM ACROSS THE ISOLATED FROG SKIN. — Previous papers reported the hypothesis that the first site of attack of cochliobolin on plant materials is probably the cell membrane. Indeed, an impairement of cell permeability, possibly disrupting the processes and the structures which regulate the active adsorption, appears as the common origin of all the phenomena observed. A study of the effects of cochliobolin on net active transfer of sodium across the isolated frog skin might therefore help to elucidate the mechanism of action of the toxin. Esperiments carried on with this aim, showed that over a range of cochliobolin concentration from 30 to 0,2 μg/ml, the net transfer of sodium is markedly promoted during the first 60–90 minutes. Moreover, with intermediate concentrations, a first increase of sodium transfer is followed by a second larger one. These informations cannot yet be readily rationalized; however they offer further evidence that an interference with active adsorption, presumably acting on the cell membrane activity, must be regarded as the first locus of cochliobolin mechanism of action.     

Epiphylly in a Variant of Helianthus Annuus x H. Tuberosus Induced by In vitro Tissue culture

A variant clone (EMB-2) derived by in vitro tissue culture of the interspecific hybrid Helianthus annuus x Helianthus tuberosus shows a particular deviation from the usual pattern of plant development in that it produces, both in vitro and in vivo, epiphyllous embryos and/or shootlike structures. Ectopic structures, which are usually arranged in clusters or rows along preexisting veins, originate asynchronously from epidermal cells of the adaxial surface of the leaf blade. Sometimes embryos and buds are also detected on the adaxial plane of the petioles and at the nodes of the stem. EMB-2 individual plants differ greatly in terms of the timing and extent of phenotypic expression of epiphylly. Leaves precociously affected by ectopic structures show a more drastic alteration in the differentiation process. Growth is arrested, the spongy parenchyma and air spaces are absent, and the mesophyll cells do not enlarge. Excluding the veins and epidermis, the leaves are wholly composed of isodiametric cells that are regularly arranged in parallel rows that have dense cytoplasm and prominent nuclei. Ectopic structures isolated from leaves and cultured in vitro mostly produce plantlets with the same phenotype as the original clones. In vivo, the EMB-2 plants are propagated by tubers. Often, the shoot-meristems that originate from tubers exhibit a teratological appearance and die without further development. However, several normal shoots grow and produce plants that display epiphyllous structures like those of the parent plants. Alterations of the endogenous hormonal levels or mutations in genes involved in the switch from indeterminate to determinate cell fate may be responsible for the ectopic development of shoots and embryos on leaves of EMB-2 variant.     

Purification,Characterization, and Inhibition of Tyrosinase from Jerusalem Artichoke (Helianthus Tuberosus L.) Tuber

Background:Because it tends to cause deterioration in the quality of food and appearance, food browning is unacceptable. Tyrosinase, which catalyzes the transformation of mono phenolic compounds into o-quinones, has been associated with this phenomenon. Natural anti-browning agents were used to help avoid the enzymatic browning that occurs in many foods.Methods:Tyrosinase of Jerusalem Artichoke tubers was purified through (NH4)2SO4 sedimentation, dialysis, chromatography, and finally gel electrophoresis. The purified enzyme was characterized and inhibited by rosemary extracts.Results:Purification of tyrosinase from Jerusalem Artichoke tuber were accomplished. The specific activity at the final step of purification increased to 14115.76 U/mg protein with purification fold 32.89 using CM-Cellulose chromatography. The molecular mass was evaluated by electrophoresis and found to be 62 KDa. Maximum tyrosinase activity was found at 30 °C, pH 7.2, and higher affinity towards L-tyrosine. Inhibition percentage of heated extracts for leaves and flowers on tyrosinase activity was better than nonheated with 29.65% and 23.75%, respectively. The kinetic analysis exposed uncompetitive inhibition by leaves and flowers heated extracts. Conclusion:In this study, we concluded the usage of natural anti-browning inhibitors like rosemary extract be able to be castoff to substitute the chemical agents which might be dangerous to social healthiness. Natural anti-browning agents can be used to prevent the browning of many foods.Key Words: Jerusalem artichoke, Rosemary, Tyrosinase     

Sull'uso della combinazione specifica caratteristica nei confronti tra i tipi di vegetazione

Abstract

On the use of characteristic specific combination to compare vegetational types. – A comparison between ordination and classification of phyto-sociological types using synthetic tables and characteristic specific combination of Raabe was made. The results of classification and ordination are very similar in both the cases, so that we can propose the characteristic specific combination of Raabe as a good method to limit the number of species when the vegetational types have to be classified.     

Transformation of Tobacco with Genes Encoding Helianthus Tuberosus Agglutinin (HTA) Confers Resistance to Peach-Potato Aphid (Myzus persicae)

The effects of the hta gene encoding Helianthus tuberosus agglutinin (HTA) on an insect in the order Homoptera were investigated. Homologous cDNAs of hta-a, hta-b, hta-c and hta-d with CaMV35S as promoter were introduced into tobacco via Agrobacterium tumefaciens. Southern blot results showed that the exogenous hta gene was inserted into the genome of host plants, and northern blot analysis confirmed that hta was expressed in transgenic plants. A bioassay with peach-potato aphid (Myzus persicae) demonstrated that transgenic plants had deleterious effects on the insect. The average population of aphids fed on transgenic T₀ plants during an 11-day assay decreased by 70%, compared controls. In transgenic plants of T₁ generation, aphid fecundity inhibitions were 53.0%(hta-b) and 64.6% (hta-c), respectively. The development of aphids was notably retarded. We conclude that hta could be a novel and promising candidate for plant transgenic engineering against homopteran insect pests.     

Effetto Della Colchicina Su Enzimi Solfidrilici

Abstract

The effect of colchicine on sulfhydryl enzymes. — The effect of colchicine has been tested on mithocondrial ATPase and rat-liver LDH. The colchicine inhibits ATPase for 40% and LDH for 100%, therefore its action is aspecific.     

Effetto del Prodotto Brachizzante “AMO-1618” sulla Crescita e sul Contenuto in Alcaloidi di Datura Stramonium L.

Abstract

The influence of the growth retarding chemical « AMO-1618 » on the growth and alkaloid content in DATURA STRAMONIUM L. — AMO-1618 (4-hydroxy-5-isopropyl-2-methylphenyl trimethylammonium chloride, 1-piperidine carboxylate) in concentration of 100 and 500 p.p.m. was applied as an aqueous spray, every day for a fortnight period, to the leaves and tops of Datura stramonium L.

The treated plants showed a reduction in growth only at the beginning, they looked, however, expecially the ones receiving the treatment with the highest concentration of the compound, more compact, sturdier and with leaves darker green and more thickened than the control. The plants were harvested four weeks following treatment. Fresh and dry weight data of leaves and roots indicated no significant change in stramonium plants treated with 100 p.p.m., while the ones treated with 500 p.p.m. showed an appreciable increase in leaves weights accompanied by a decrease in roots weights.

No significant difference, between treated and untreated plants, was observed in the concentration of total alkaloids in the leaves and in the roots.     

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.