Challenges and opportunities of light-emitting diode (Led) as key to modulate antioxidant compounds in plants. a review

Plant antioxidants are important compounds involved in plant defense, signaling, growth, and development. The quantity and quality of such compounds is genetically driven; nonetheless, light is one of the factors that strongly influence their synthesis and accumulation in plant tissues. Indeed, light quality affects the fitness of the plant, modulating its antioxidative profile, a key element to counteract the biotic and abiotic stresses. With this regard, light-emitting diodes (LEDs) are emerging as a powerful technology which allows the selection of specific wavelengths and intensities, and therefore the targeted accumulation of plant antioxidant compounds. Despite the unique advantages of such technology, LED application in the horticultural field is still at its early days and several aspects still need to be investigated. This review focused on the most recent outcomes of LED application to modulate the antioxidant compounds of plants, with particular regard to vitamin C, phenols, chlorophyll, carotenoids, and glucosinolates. Additionally, future challenges and opportunities in the use of LED technology in the growth and postharvest storage of fruits and vegetables were also addressed to give a comprehensive overview of the future applications and trends of research

Plant antioxidants for food safety and quality: Exploring new trends of research

Antioxidants are an heterogeneous group of compounds able to counteract cell oxidation by acting as reducing agents, as free radical scavengers, and quenchers of radical species and other pro-oxidants, such as metals [...]

Effects of postharvest light spectra on quality and health-related parameters in green Asparagus officinalis L

The monitoring of quality parameters in horticultural crops under artificial light during postharvest storage is important for controlling the shelf-life of the crops. In this work, white light, red light, blue light and dark conditions were used at various durations to evaluate the effects of different spectral properties of light on parameters related to physiological and biochemical processes in green asparagus, and on compounds related to human health. For this aim, the level of glucose, fructose and sucrose, as well as that of vitamin C and the levels of lignin, chlorophyll a and b, carotenoids and anthocyanins, were determined in apical and basal segments of the edible portion of green asparagus spears before and after light treatments. A dark control was stored at 4 C. The irradiance levels of the light treatments were 100, 117 and 116 mmol m2 s1, respectively for white, blue and red light. Before treatments, in the apical segments, the content of analysed components were higher than in the basal segments, except for soluble sugars and starch, of which the basal segment exhibited higher levels; these results exhibited different nutritional value of the two segments. After the light treatments, the analysed quality-related parameters were differently influenced in the apical and basal segments during postharvest storage. The increase in dry matter content in the apical segment after both white light and red light treatments was most likely attributable to the presence of physiological postharvest activity, rather than to increased transpiration. The results indicated that light with different spectral properties vs. dark-stored controls had small or no effects on the measured parameters. Both light and dark caused the starch levels to increase in both segments. A decrease in the sugar content in the basal part might be explained by translocation of hexoses from basal towards apical regions of the spear. White light primarily determined the lignin deposition in the apical part most likely due to the synergistic effect of red and blue light on lignin biosynthesis. The vitamin C, chlorophyll a and b and carotenoids decreased in light and dark treatments in both segments. Anthocyanins were induced by light in the basal part only, most so by blue light

The Arbuscular Mycorrhizal Fungus Glomus viscosum Improves the Tolerance to Verticillium Wilt in Artichoke by Modulating the Antioxidant Defense Systems

Verticillium wilt, caused by the fungal pathogen Verticillium dahliae, is the most severe disease that threatens artichoke (Cynara scolymus L.) plants. Arbuscular mycorrhizal fungi (AMF) may represent a useful biological control strategy against this pathogen attack, replacing chemical compounds that, up to now, have been not very effective. In this study, we evaluated the effect of the AMF Glomus viscosum Nicolson in enhancing the plant tolerance towards the pathogen V. dahliae. The role of the ascorbate-glutathione (ASC-GSH) cycle and other antioxidant systems involved in the complex network of the pathogen-fungi-plant interaction have been investigated. The results obtained showed that the AMF G. viscosum is able to enhance the defense antioxidant systems in artichoke plants affected by V. dahliae, alleviating the oxidative stress symptoms. AMF-inoculated plants exhibited significant increases in ascorbate peroxidase (APX), monodehydroascorbate reductase (MDHAR), and superoxide dismutase (SOD) activities, a higher content of ascorbate (ASC) and glutathione (GSH), and a decrease in the levels of lipid peroxidation and hydrogen peroxide (H2O2). Hence, G. viscosum may represent an effective strategy for mitigating V. dahliae pathogenicity in artichokes, enhancing the plant defense systems, and improving the nutritional values and benefit to human health

Effects of Darkness and Light Spectra on Nutrients and Pigments in Radish, Soybean, Mung Bean and Pumpkin Sprouts

Fresh sprouts are an important source of antioxidant compounds and contain useful phytonutrients in the human diet. Many factors, such as the time of germination and types of light, influence the physiological processes and biosynthetic pathways in sprouts. The effect of red, blue and white light vs. dark conditions on the quality parameters in different sprout species after 5 d of germination was evaluated. Total ascorbate, soluble proteins, sugars, phenolic compounds, and pigments, such as carotenoids, chlorophylls, and anthocyanins, were investigated in radishes, soybeans, mung beans, and pumpkin sprouts. The light treatments increased the contents of vitamin C and the various pigments in all sprouts, conversely, they increased the soluble proteins and sugars, includingd-glucose,d-fructose and sucrose, in soybeans and pumpkins, respectively. The dark treatment prevented the decrease in dry matter due to the lighting, while the red light induced an increase in polyphenols in soybean. These results suggest that the nutritional content of different sprouts grown under different light conditions depend on the dark or specific spectral wavelength used for their growth. The manuscript may increase the knowledge on light use for the industrialized food production aiming at preserving the phytonutrient content of vegetables, increasing the consumer health, or developing tailored diets for specific nutritional needs

Saranda: forma della natura e forma della città. Il progetto come sistema di istanze

La ricerca indaga il rapporto tra la forma della terra e dell’acqua e le forme urbane nell’area meridionale dell’Albania, del territorio di Saranda e della laguna di Butrinto. Essa affronta la necessità di definire opportune grammatiche per modelli insediativi in grado di interpretare la bellezza e l’articolazione topografica e capaci di stabilire una continuità con i principi fondativi delle città greche e romane, i cui resti testimoniano l’esistenza di una tradizione insediativa costruita sulla unicità e sul valore geografico del sito. La ricerca si divide in due parti; la prima parte si costituisce della lettura delle relazioni e del significato delle tracce stratigrafiche permanenti nel territorio, la seconda presenta l’esito della sperimentazione applicata al caso studio. La ricerca, effettuata mediante gli strumenti di morfologia urbana, è stata circoscritta all’area compresa tra due crinali che, paralleli alla costa, definiscono una vera e propria stanza territoriale. Tali promontori non soltanto rappresentano i confini geografici del sito ma raccolgono caratteri insediativi peculiari e omogenei (terrazzamenti, fortificazioni e torri, insediamenti rurali e di promontorio…). Dallo studio emergono le ragioni e i principi che presiedono le forme del costruito e spiegano gli esiti formali delle città e dei piccoli nuclei urbani integrati e coesi alla geografia del sito. I risultati orientano il progetto alla trasformazione della città e del territorio in accordo con quelli che sono i valori ambientali, storici e insediativi del luogo. Il progetto indirizza ad in sistema insediativo lineare, misura del territorio e sistema organico dei nuclei urbani, dei presidi del territorio, dei luoghi dell’antico, di quelli cospicui del paesaggio

Sarande: water, forma terrae and forma urbis

Ponència presentada a: Session 9: Diseño e Historia (modernidad y tradición) / Design and History (modernity and tradition

Sarande: water, forma terrae and forma urbis

Ponència presentada a: Session 9: Diseño e Historia (modernidad y tradición) / Design and History (modernity and tradition

Proximal-sensing-powered modelling of energy-water fluxes in a vineyard: A spatial resolution analysis

Spatial resolution is a key parameter in energy–water surface flux modelling. In this research, scale effects are analyzed on fluxes modelled with the FEST-EWB model, by upscaling both its inputs and outputs separately. The main questions are: (a) if high-resolution remote sensing images are necessary to accurately model a heterogeneous area; and (b) whether and to what extent low-resolution modelling provides worse/better results than the upscaled results of high-resolution modelling. The study area is an experimental vineyard field where proximal sensing images were obtained by an airborne platform and verification fluxes were measured via a flux tower. Modelled fluxes are in line with those from alternative energy-balance models, and quite accurate (NSE = 0.78) with respect to those measured in situ. Field-scale evapotranspiration has resulted in both the tested upscaling approaches (with relative error within ±30%), although fewer pixels available for low-resolution calibration may produce some differences. When working at low resolutions, the model has produced higher relative errors (20% on average), but is still within acceptable bounds. This means that the model can produce high-quality results, partially compensating for the loss in spatial heterogeneity associated with low-resolution images