Studio dell'efficienza di fitoestrazione da parte della felce Pteris vittata L. in un terreno contaminato da arsenico

L’arsenico è un metalloide tossico, causa di avvelenamenti e responsabile di alterazioni cancerose della pelle, dei polmoni e della vescica. Sebbene normalmente diffuso nell’ambiente, le numerose attività antropiche, come la lavorazione dei metalli, la combustione del carbone, le attività minerarie, la produzione di sostanze coloranti di prodotti chimici e antiparassitari, hanno contribuito ad aumentarne i livelli specialmente nel suolo. È stato stimato che nell’ultimo decennio le immissioni di arsenico da parte dell’uomo si sono collocate tra 52000 a 112000 tonnellate/anno. La Phytoremediation è una tecnologia emergente basata sulla capacità di alcune piante di rimuovere particolari sostanze contaminanti da suoli e acque, che negli ultimi anni è oggetto di particolare attenzione da parte della comunità scientifica in virtù soprattutto dei bassi costi e del ridotto impatto ambientale. Uno dei meccanismi fisiologici, noto come iperaccumulo, riguarda la capacità di certe piante di assorbire grandi quantità di una sostanza inquinante (solitamente un metallo tossico) accumulandola all’interno delle cellule. In questo modo i contaminanti vengono progressivamente rimossi dal terreno eliminando le piante. Sebbene siano note numerose specie vegetali adatte alla rimozione di un’ampia varietà di elementi tossici nessuna pianta aveva dimostrato un comportamento come iperaccumulatrice di arsenico fino alla recente scoperta della felce Pteris vittata L. che ha aperto potenzialmente la porta alla phytoremediation di siti contaminati da arsenico. Nel presente lavoro, una volta ottimizzate le tecniche di coltivazione della felce, sono state allestite prove in idroponica e su terreni provenienti da un ex sito industriale contaminato da As. In idroponica le piante sono state esposte a soluzioni nutritive a concentrazioni crescenti di arsenato e arsenito di sodio e della combinazione di entrambi i sali. Per quanto riguarda le prove su terreno, è stata, in primo luogo, valutata la capacità di adattamento di P. vittata a suoli marginali di tipo industriale e successivamente, l’efficienza di fitoestrazione dell’arsenico. Per ciascuna prova, sono stati prelevati campioni di radici e fronde e sottoposti ad analisi mediante ICP-OES (Inductively Coupled Plasma-Optical Emission Spectrometry) per misurarne le quantità di arsenico accumulate. I risultati di questo studio dimostrano, oltre a sorprendenti potenzialità di adattamento a diverse situazioni ambientali, soprattutto la straordinaria abilità di P. vittata ad iperaccumulare elevate concentrazioni di As soprattutto nelle fronde rivelando una efficiente capacità di traslocazione dalle radici alla parte epigea

Internal aeration and respiration of submerged tomato hypocotyls is enhanced by ethylene‐mediated aerenchyma formation and hypertrophy

With the impending threat that climate change is imposing on all terrestrial ecosystems, plants ability to adjust to changing environments is, more than ever, a very desirable trait. Tomato (Solanum lycopersicum L.) plants display a number of responses that allow them to survive under different abiotic stresses such as flooding. We focused on understanding the mechanism that facilitates oxygen diffusion to submerged tissues and the impact it has on sustaining respiration levels. We observed that, as flooding stress progresses, stems increase their diameter and internal porosity. Ethylene triggers stem hypertrophy by inducing cell wall loosening genes, and aerenchyma formation seems to involve programmed cell death mediated by oxygen peroxide. We finally assessed whether these changes in stem morphology and anatomy are indeed effective to restore oxygen levels in submerged organs. We found that aerenchyma formation and hypertrophy not only increase oxygen diffusion towards the base of the plant but also result in an augmented respiration rate. We consider that this response is crucial to maintain adventitious root development under such conditions and, therefore, making it possible for the plant to survive when the original roots die.Fil: Mignolli, Francesco. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; ArgentinaFil: Todaro, Juan Santiago. Universidad Nacional del Nordeste. Facultad de Medicina; ArgentinaFil: Vidoz, María Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; Argentin

Gibberellins modulate auxin responses during tomato (Solanum lycopersicum L.) fruit development

In tomato, auxin and gibberellins (GAs) interact with each other to drive fruit growth and development. While the role of auxin in directing GA biosynthesis and signal is already known, very little information has been obtained about GA-mediated control of auxin signalling and response. Interestingly, we show that gibberellic acid (GA 3 ) is able to modify the expression of several auxin signalling genes in the partial auxin-insensitive diageotropica (dgt) mutant, suggesting that GAs may override the control of DGT on auxin signal. Procera (pro) mutation, which confers a constitutively active GA signal, enhances the effects of exogenous auxin, indicating that PRO may act as a negative effector of auxin responses in fruits. Indeed, transcript modulation of some auxin/indole acetic acid and auxin response factor genes in auxin-treated dgt/pro fruits suggests that PRO controls their expression possibly bypassing DGT. It was also shown that GA biosynthesis, in response to auxin treatment, is largely controlled by DGT. It is therefore conceivable that the DGT-mediated increase of active GAs in auxin-treated or pollinated fruits would promote PRO degradation, which in turn activates part of the auxin signalling cascade.Fil: Mignolli, Francesco. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; ArgentinaFil: Vidoz, María Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; ArgentinaFil: Picciarelli, Piero. Università degli Studi di Pisa; ItaliaFil: Mariotti, Lorenzo. Università degli Studi di Pisa; Itali

extraction and determination of ascorbate and dehydroascorbate from apoplastic fluid of stem of rooted and non rooted cuttings in relation to the rhizogenesis

Starting from semihardwood branches of peach and plum rootstocks (Prunus cerasifera E.) cv. MRS2/5, plum rootstocks (Prunus cerasifera × P. salicina) × (P. cerasifera × P. persica) cv. Ishtarà and olive tree (Olea europaea L.) cv. Frantoio, cuttings were collected and treated with 0 mg.L-1 and 2500 mg.L-1 of indolebutyric acid (IBA) by immersion in the base of the cuttings. After 60 days of planting, the cultivars MRS 2/5, Ishtarà and Frantoio presented a significative difference with relation to the rooting induction by application of the indolebutyric acid (27.5, 47.5 and 41.25 %, respectively), inducing a higher number of roots per cutting without at the same time significantly increasing the length of the roots themselves. The levels of ascorbate and dehydroascorbate in the rooted and non-rooted cuttings of the three cultivars were determined. These parameters varied in function of the consistency of the cuttings from each species, but showed a positive correlation between the increase of the rooting and the increase of the ascorbate in the reduced form

Maintenance of photosynthetic capacity in flooded tomato plants with reduced ethylene sensitivity

Ethylene is considered one of the most important plant hormones orchestrating plant responses to flooding stress. However, ethylene may induce deleterious effects on plants, especially when produced at high rates in response to stress. In this paper, we explored the effect of attenuated ethylene sensitivity in the Never ripe (Nr) mutant on leaf photosynthetic capacity of flooded tomato plants. We found out that reduced ethylene perception in Nr plants was associated with a more efficient photochemical and non-photochemical radiative energy dissipation capability in response to flooding. The data correlated with the retention of chlorophyll and carotenoids content in flooded Nr leaves. Moreover, leaf area and specific leaf area were higher in Nr, indicating that ethylene would exert a negative role in leaf growth and expansion under flooded conditions. Although stomatal conductance was hampered in flooded Nr plants, carboxylation activity was not affected by flooding in the mutant, suggesting that ethylene is responsible for inducing non-stomatal limitations to photosynthetic CO2 uptake. Upregulation of several cysteine protease genes and high protease activity led to Rubisco protein loss in response to ethylene under flooding. Reduction of Rubisco content would, at least in part, account for the reduction of its carboxylation efficiency in response to ethylene in flooded plants. Therefore, besides its role as a trigger of many adaptive responses, perception of ethylene entails limitations in light and dark photosynthetic reactions by speeding up the senescence process that leads to a progressive disassembly of the photosynthetic machinery in leaves of flooded tomato plants.Fil: de Pedro, Leandro Federico. Universidad Nacional de Formosa. Facultad de la Producción y El Medioambiente; ArgentinaFil: Mignolli, Francesco. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; ArgentinaFil: Scartazza, Andrea. Consiglio Nazionale delle Ricerche; ItaliaFil: Melana Colavita, Juan Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Básica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Básica y Aplicada del Nordeste Argentino; ArgentinaFil: Bouzo, Carlos Alberto. Universidad Nacional del Litoral; ArgentinaFil: Vidoz, María Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; Argentin

The hypoxic microenvironment induces stearoyl-coa desaturase-1 overexpression and lipidomic profile changes in clear cell renal cell carcinoma

Clear cell renal cell carcinoma (ccRCC) is the most common histological subtype of renal cell carcinoma (RCC). It is characterized by a high cell proliferation and the ability to store lipids. Previous studies have demonstrated the overexpression of enzymes associated with lipid metabolism, including stearoyl-CoA desaturase-1 (SCD-1), which increases the concentration of unsaturated fatty acids in tumor cells. In this work, we studied the expression of SCD-1 in primary ccRCC tumors, as well as in cell lines, to determine its influence on the tumor lipid composition and its role in cell proliferation. The lipidomic analyses of patient tumors showed that oleic acid (18:1n-9) is one of the major fatty acids, and it is particularly abundant in the neutral lipid fraction of the tumor core. Using a ccRCC cell line model and in vitro-generated chemical hypoxia, we show that SCD-1 is highly upregulated (up to 200-fold), and this causes an increase in the cellular level of 18:1n-9, which, in turn, accumulates in the neutral lipid fraction. The pharmacological inhibition of SCD-1 blocks 18:1n-9 synthesis and compromises the proliferation. The addition of exogenous 18:1n-9 to the cells reverses the effects of SCD-1 inhibition on cell proliferation. These data reinforce the role of SCD-1 as a possible therapeutic target.Fil: Melana Colavita, Juan Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Básica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Básica y Aplicada del Nordeste Argentino; ArgentinaFil: Mignolli, Francesco. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; ArgentinaFil: Stoyanoff, Tania Romina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Básica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Básica y Aplicada del Nordeste Argentino; ArgentinaFil: Aguirre, María Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Básica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Básica y Aplicada del Nordeste Argentino; ArgentinaFil: Balboa, María A.. Consejo Superior de Investigaciones Científicas; España. Universidad de Valladolid; EspañaFil: Balsinde Rodríguez, Jesús. Consejo Superior de Investigaciones Científicas; España. Universidad de Valladolid; EspañaFil: Rodríguez, Juan Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Básica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Básica y Aplicada del Nordeste Argentino; Argentin

Cultivo in vitro de embriones aislados a partir de semillas de frutos inmaduros de irupé (Victoria cruziana, Nymphaeaceae)

The irupé or water corn (Victoria cruziana A. D. Orb.) belongs to the Nymphaeaceae family and arouses interest mainly due to the beauty of its leaves and flowers. Obtaining seeds of this aquatic species in its natural environment is challenging, and it is also considered a recalcitrant species for in vitro culture. For this reason, the aim of this work was to establish a methodology for the conversion into plants of irupé embryos extracted from seeds of immature fruits and to obtain material to be used in micropropagation or in environmental restoration programs. Embryo culture of fruits in six growth stages was carried out up to a maximum of four weeks. Using Murashige & Skoog’s basal medium, twelve culture media with and without the addition of growth regulators (gibberellic acid, AG3 and thidiazuron, TDZ) were tested. Embryos converted into plants in all media diluted to 50% (½ MS) with 3% sucrose, while plants with developed roots were obtained in the medium with the addition of 10 mg/L of GA3 . Although the culture of embryos derived from seeds in early fruit stages did not allow plant regeneration, this was possible when explants derived from fruits in late developmental stages.El irupé o maíz de agua (Victoria cruziana A. D. Orb.) pertenece a la familia Nymphaeaceae y despierta interés, principalmente, por la belleza de sus hojas y flores. La obtención de semillas de esta especie acuática es dificultosa en su ambiente natural y además es considerada recalcitrante para el cultivo in vitro. Por este motivo, el objetivo de este trabajo fue el establecimiento de una metodología para la conversión a plantas de embriones de irupé extraídos de semillas de frutos inmaduros y la obtención de material para ser empleado en la micropropagación o en programas de restauración ambiental. Se realizó el cultivo de embriones de frutos con seis estadios de crecimiento, hasta un máximo de cuatro semanas. Empleando el medio basal de Murashige & Skoog, se probaron doce medios de cultivo con y sin el agregado de reguladores de crecimiento (ácido giberélico, AG3 y thidiazuron, TDZ). Los embriones se convirtieron en plantas en todos los medios diluidos al 50% (½ MS), manteniendo el 3% de sacarosa, mientras que en el medio adicionado con 10 mg/L de AG3 se obtuvieron plantas con raíces desarrolladas. Si bien el cultivo de embriones derivados de las semillas en los estadios tempranos del fruto no permitió la regeneración de plantas, esta fue posible cuando los explantes derivaron de frutos en estadios tardíos

Capacidad citocromo c oxidasa

Medición de oxigeno consumido por hipocótilos de plantas de tomate sometidas a condiciones control y de inundación luego de 3 días de tratamiento. Con el fin de calcular la capacidad máxima de la citocromo c oxidasas, el consumo de oxigeno se midió luego de haber mantenido las muestras en presencia y ausencia de cianuro de potasio.Fil: Mignolli, Francesco. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; ArgentinaFil: Vidoz, María Laura. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; Argentin

Test de tetrazolio en hipocótilos de plantas de tomate inundadas

Test con cloruro de tetrazolio en segmentos de hipocótilos de plantas de tomate sometidas a encharcamiento (waterlogging) y sumersión parcial (flooding). Las muestras fueron incubadas a 37C en la solución de TTC. Luego, el compuesto reducido del TTC fue extraído en etanol y cuantificado por espectrofotometría.Fil: Mignolli, Francesco. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; ArgentinaFil: Vidoz, María Laura. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; Argentin