17 research outputs found
Effetti dell'impiego di residui solidi dell'industria agrumaria sulla fertilita' del suolo: influenza delle sostanze umiche e sulle attivita' microbiche ed enzimatiche
No full textDottorato di ricerca in chimica agraria. 12. ciclo. A.a. 1996-99. Tutore Adalgisa Belligno Coordinatore Giacomo GalvanoConsiglio Nazionale delle Ricerche - Biblioteca Centrale - P.le Aldo Moro, 7, Rome; Biblioteca Nazionale Centrale - Piazza Cavalleggeri, 1, Florence / CNR - Consiglio Nazionale delle RichercheSIGLEITItal
Interaction ammonium-nitrate: Response to oxidative stress in chicory plants
No full textThe aim of this work was to study, as a function of the different availability of nitrogen in the reduced form, mineral and organic, the induction of the synthesis of some ROS-scavenging molecules and the evolution of some enzymatic activities such as ascorbate peroxidase (APX) and polyphenoloxidase (PPO). 
Chicory seedlings were grown in nutritive solution for 35 days in controlled conditions. On the 14th day, one third of the plants was transferred into a nutritive solution containing (NH4)2SO4 60 mM, one third was transferred into a medium containing Urea 60 mM, and the remaining was let grow into the nutrition solution, as a control. Three samplings of leaves were performed, respectively after 21, 28 and 35 days of growth.
The urea and ammonium sulphate-treated samples showed higher ascorbic acid and polyphenol contents than the control, together with a lower anthocyanins content. APX showed the highest activity in the urea-treated samples, while the highest PPO activity was to refer to samples treated with ammonium sulphate.
The variations of the organic components showed the incidence of the nitrogen supply in the reduced form on the cell redox potential, confirming the importance of fertilization for obtaining high amounts of antioxidant molecules.

Influence of different iron availability on phosphoenolpiruvate carboxilase and malate dehydrogenase in roots of maize (Zea Mays L.) plants grown under iron deficiency
No full textThe effect of the different nitrate availability on some enzymatic activities has been evaluated in iron deficient and iron sufficient maize plants (Zea mays L.). In order to evaluate if the induction of sensitive to pH enzymatic activities is affected by the variation of the apoplast reaction due to the different nitrate availability, two experimental tests were done on maize plants grown in nutrient solution with different NO3- availability and with Fe-sufficiency (+Fe) (added with 80 uM Fe(III)-EDTA) and Fe-deficiency (-Fe) (added with 0.1 uM Fe(III)-EDTA).
As regards 0.4 mM NO3- (NS2), independently of iron availability, phosphoenolpiruvate carboxilase and malate dehydrogenase inductions are higher than those recorded for the experiment with 4.0 mM NO3-. The two activities, for the reaction determined in citosol by NO3- uptake, show different responses according to Fe availability. In NS1 the higher nitrate uptake and the contemporaneous H+ incoming cause in (+Fe) plants a decrease of PEP-carboxilase activation and, during the first 24 hours, of malate dehydrogenase. The shifting of the peak of maximum activity shows that iron deficiency conditions, interfering with e- transport, determinate a slowing down of the enzyme induction, independently of nitrate availability. In NS2, PEPcase is higher under Fe-deficiency and malate dehydrogenase is higher under Fe-sufficiency, both during the first 24 hours.
The different nitrate availability causes a different use of the acid content. In fact, in NS1 citric content, precursor of molecules for the production of phytosiderophores, increased in (-Fe) theses. On the contrary, low nitrate availabilities determined a decrease in acid contents, mostly in (-Fe) theses. This result justifies the higher energy demand to activate membrane carriers under stress conditions for the reduced nitrate availability.

Influence of different iron availability on phosphoenolpiruvate carboxilase and malate dehydrogenase in roots of maize (Zea Mays L.) plants grown under iron deficiency
No full textWheat Response to a Soil Previously Irrigated with Saline Water
No full textA research was conducted aimed at assessing the response of rainfed, lysimeter-grown wheat to various levels of soil salinity, in terms of dry mass production, inorganic and organic components, sucrose phosphate synthase (SPS) and sucrose synthase (SS) activity. One additional scope was the assessment of soil ability to recover from applied salts by means of winter precipitations. The results confirmed the relatively high salt tolerance of wheat, as demonstrated by the mechanisms enacted by plants to contrast salinity at root and leaf level. Some insight was gained in the relationships between salinity and the various inorganic and organic components, as well as with SPS and SS activity. It was demonstrated that in a year with precipitations well below the average values (305 mm vs 500) the leaching action of rain was sufficient to eliminate salts accumulated during summer irrigation with saline water
Preliminary Study on Bioactive Compounds of <i>Citrus</i> × <i>myrtifolia</i> <i>Rafinesque</i> (Chinotto) to Its Potential Application in Food Industry
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Shelf Life Study of Fresh Celery (Apium graveolens L.) Grown under Different Nitrogen Fertilization Treatments
No full textSalinity influence on soil microbial population metabolism and enzymatic activities in lysimeter-grown Olea europaea and Nicotiana glauca
No full textSeawater effects on antioxidant production in berries of three cultivars of tomato (Lycopersicon esculentum mill.)
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