Aroma profile of Fuji apples treated with gelatin edible coating during their storage

This study aimed to detect possible changes in the volatile organic compounds (VOCs) of Fuji apples induced by gelatin-based edible coating (EC), during 21 days of storage at room temperature. VOCs were analyzed by solid-phase micro extraction-gas chromatography-mass spectrometry. Data were analyzed by one-way ANOVA and principal component analysis. Control apples showed a greater presence of total aldehydes and acids at 7 and 14 days, respectively, while coated apples were characterized by higher proportions of alcohols (from 1.3- to 2-fold) at 7 day till the end of the storage. The higher ethanol proportions detected in coated apples (154-fold higher after 7 days) indicate a likely partial anaerobiosis, confirmed by the lower CO2 emission (reaching -68% after 21 days). Esters responsible of the varietal aroma of Fuji were identified also in coated fruits, suggesting that gelatin did not modify the typical aroma extensively. Acetate esters, normally increasing with maturity, were less concentrated in coated apples (-78% 2-methylbutyl acetate and -73% hexyl acetate, after 1 and 7 days respectively), suggesting a likely slowdown of the ripening due to the EC. Further investigation is needed to improve this storage technology considering that aroma is an important determinant of food quality

Physiological and Biochemical Adaptive Traits in Leaves of Four Citrus Species Grown in an Italian Charterhouse

Citrus trees are a very important crops that are cultivated worldwide, but not much knowledge is known about the ecophysiological responses to climatic changes in trees under natural conditions. The aim of this study was to investigate their adaptive capacity in response to seasonal phenological and environmental changes. The trial included Citrus trees (sweet orange, bitter orange, lemon, mandarin) growing under non-regular cropping conditions in a Monumental Charterhouse in Tuscany, in a subtropical Mediterranean climate with hot summer conditions. During a 1-year field trial, we determined the variations in chlorophyll fluorescence parameters and leaf biochemical traits (content of chlorophylls and carotenoids, total phenolic content (TPC), total antioxidant capacity (TAC), and total non-structural carbohydrates). In all Citrus spp., interspecific mean values of photochemical efficiency peaked during the summer, while a marked photoinhibition occurred in the winter in concomitance with higher interspecific mean values of leaf TPC, TAC, and non-structural carbohydrates. The trees showed the pivotal role played by photosynthetic acclimation as a survival strategy to tolerate abiotic stress in the climate change hotspot of Mediterranean environment. This study is included in a wider project aimed at a new valorization of Citrus trees as genetic resource and its by-products with added-value applications for innovative functional foods

De-inked paper sludge and mature compost as high-valuecomponents of soilless substrate to support tree growth

The recycled paper industry produces tons of waste whose disposal is a cost for industry and the environment. This research examines the suitability of de-inked paper sludge (DPS), after pelletization, as a sustainable alternative component to a peat-based growing media, creating ideal root conditions for tree development (e.g. high water storage, low compaction). DPS, tested on Lepidium sativum L. germination, did not show toxicity effects. Three species, Quercus ilex L., Lagerstroemia indica L. and Prunus serrulata “Kanzan”, were planted in 40 cm Ø pots filled with a control (peat, pumice and zeolite) and the experimental substrate (compost, DPS pellets, pumice and zeolite). After two years in the nursery, the trees were planted in situ. The physical and chemical properties of substrates were analyzed. Plant morphological and physiological parameters were monitored: trunk diameter, leaf dry matter, leaf nitrogen, chlorophyll, and photosynthetic efficiency. The new substrate showed higher Corg (+135%), total N (+73%) and easily available water (+19%), compared to the control substrate used in the nursery. In this new substrate, the trees showed similar radial growth values to the control in the nursery and after transplanting in situ improved their photosynthetic performance in terms of quantum yield of photosystem II (+36%, and +29% in P. serrulata and L. indica, respectively) and electron transport rate (+39%, +25%, and +32% in P. serrulata, Q. ilex and L. indica, respectively). Pelletization represents an attractive amendment for growing media, which enhances the plant’s physiological health status. This study proposes alternative recovery methods for paper industry waste with low environmental impact. As the process is developed locally, it should also contribute to reducing energy-related CO2 emissions from transport. Pelletization represents an attractive novelty in the use of DPS as amendment for growing media, which enhances the plant’s physiological health status. This study proposes alternative recovery methods for paper industry waste with low environmental impact. As the process is developed locally, it should also contribute to reducing energy-related CO2 emissions from transport

Physiological effects of short acute UVB treatments in Chenopodium quinoa Will

Increased ultraviolet B (UVB) radiation due to global change can affect plant growth and metabolism. Here, we evaluated the capacity of quinoa to resist under short acute UVB irradiation. Quinoa was daily exposed for 30 or 60 min to 1.69 W m−2 UVB. The results showed that 30 min exposure in 9 d-course did not cause severe alterations on photosynthetic pigments and flavonoids, but a significant increase of antioxidant capacity was observed. Otherwise, 60 min UVB in 5 d-course reduced almost all these parameters except for an increase in the de-epoxidation of xanthophyll cycle pigments and led to the death of the plants. Further studies of gas exchange and fluorescence measurements showed that 30 min UVB dramatically decrease stomatal conductance, probably associated to reactive oxygen species (ROS) production. Inhibition of photosynthetic electron transport was also observed, which could be a response to reduce ROS. Otherwise, irreversible damage to the photosynthetic apparatus was found with 60 min UVB probably due to severe ROS overproduction that decompensates the redox balance inducing UVB non-specific signaling. Moreover, 60 min UVB compromised Rubisco carboxylase activity and photosynthetic electron transport. Overall, these data suggest that quinoa modulates different response mechanisms depending on the UVB irradiation dosage

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

Physiological responses of maca (Lepidium meyenii Walp.) plants to UV radiation in its high-altitude mountain ecosystem

Ultraviolet (UV) radiation is a small fraction of the solar spectrum, which acts as a key environmental modulator of plant function affecting metabolic regulation and growth. Plant species endemic to the Andes are well adapted to the harsh features of high-altitude climate, including high UV radiation. Maca (Lepidium meyenii Walpers) is a member of Brassicaceae family native to the central Andes of Peru, which grows between 3500 and 4500 m of altitude, where only highland grasses and few hardy bushes can survive. Even though maca has been the focus of recent researches, mainly due to its nutraceutical properties, knowledge regarding its adaptation mechanisms to these particular natural environmental conditions is scarce. In this study, we manipulated solar UV radiation by using UV-transmitting (Control) or blocking (UV-block) filters under field conditions (4138 m above the sea level) in order to understand the impact of UV on morphological and physiological parameters of maca crops over a complete growing season. Compared to the UV-blocking filter, under control condition a significant increase of hypocotyl weight was observed during the vegetative phase together with a marked leaf turnover. Although parameters conferring photosynthetic performance were not altered by UV, carbohydrate allocation between above and underground organs was affected. Control condition did not influence the content of secondary metabolites such as glucosinolates and phenolic compounds in hypocotyls, while some differences were observed in the rosettes. These differences were mainly related to leaf turnover and the protection of new young leaves in control plants. Altogether, the data suggest that maca plants respond to strong UV radiation at high altitudes by a coordinated remobilization and relocation of metabolites between source and sink organs via a possible UV signaling pathway

Photosynthetic and Growth Responses of Arundo donax L. Plantlets Under Different Oxygen Deficiency Stresses and Reoxygenation

Promotion of nonfood species production to marginal, degraded lands abandoned by mainstream agriculture is affected by extremes of water availability (droughts and floods), which have increased in frequency and intensity and account for severe yield reduction. Arundo donax L., known as giant cane or giant reed, spontaneously grows in different kinds of environments with limitation to low temperature and is thus widespread in temperate and hot areas around the world. Moreover, this perennial rhizomatous grass has been recognized as a leading candidate crop in the Mediterranean for lignocellulosic feedstock due to its high C3 photosynthetic capacity, positive energy balance and low agroecological management demand. In this study, the photosynthetic performance and growth response of A. donax to waterlogging and submergence stress following a time course as well as their respective re-oxygenation were analyzed under reproducible and controlled environment conditions. Results of growth response showed that biomass production was strongly conditioned by the availability of oxygen. In fact, only waterlogged plants showed similar growth capacity to those under control conditions, while plants under submergence resulted in a dramatic reduction of this trait. The simultaneous measurements of both gas exchanges and chlorophyll fluorescence highlighted an alteration of both stomatal and non-stomatal photosynthetic behaviors during a short/medium period of oxygen deprivation and re-oxygenation. Photosynthetic CO2 uptake was strictly related to a combination of stomatal and mesophyll diffusional constrains, depending on the severity of the treatment and exposure time. Conditions of waterlogging and hypoxia revealed a slight growth plasticity of the species in response to prolonged stress conditions, followed by a fast recovery upon reoxygenation. Moreover, the rapid restoration of physiological functions after O2 deprivation testifies to the environmental plasticity of this species, although prolonged O2 shortage proved detrimental to A. donax by hampering growth and photosynthetic CO2 uptake

Salinity in Autumn-Winter Season and Fruit Quality of Tomato Landraces

Tomato landraces, originated by adaptive responses to local habitats, are considered a valuable resource for many traits of agronomic interest, including fruit nutritional quality. Primary and secondary metabolites are essential determinants of fruit organoleptic quality, and some of them, such as carotenoids and phenolics, have been associated with beneficial proprieties for human health. Landraces' fruit taste and flavour are often preferred by consumers compared to the commercial varieties' ones. In an autumn-winter greenhouse hydroponic experiment, the response of three Southern-Italy tomato landraces (Ciettaicale, Linosa and Corleone) and one commercial cultivar (UC-82B) to different concentrations of sodium chloride (0 mM, 60 mM or 120 mM NaCl) were evaluated. At harvest, no losses in marketable yield were noticed in any of the tested genotypes. However, under salt stress, fresh fruit yield as well as fruit calcium concentration were higher affected in the commercial cultivar than in the landraces. Furthermore, UC-82B showed a trend of decreasing lycopene and total antioxidant capacity with increasing salt concentration, whereas no changes in these parameters were observed in the landraces under 60 mM NaCl. Landraces under 120 mM NaCl accumulated more fructose and glucose in the fruits, while salt did not affect hexoses levels in UC-82B. Ultra-performance liquid chromatography-tandem mass spectrometry analysis revealed differential accumulation of glycoalkaloids, phenolic acids, flavonoids and their derivatives in the fruits of all genotypes under stress. Overall, the investigated Italian landraces showed a different behaviour compared to the commercial variety UC-82B under moderate salinity stress, showing a tolerable compromise between yield and quality attributes. Our results point to the feasible use of tomato landraces as a target to select interesting genetic traits to improve fruit quality under stress conditions

Ecophysiology of Yucca gloriosa in a Mediterranean sand dune environment

The C3–CAM (crassulacean acid metabolism) intermediate species Yucca gloriosa L. is invading coastal dunes in central Italy, causing a loss in biodiversity and habitat. In order to investigate its competitive success, a number of ecophysiological traits were analysed: CAM activity (through carbon isotope composition, δ13C, and cell acidification), photochemical efficiency of PSII (operating and maximum photosystem II quantum yield), stomatal conductance, relative water content, and succulence index (SI). Analyses were conducted over the course of one year, to assess yucca’s response to seasons and the shoreline-inland ecological gradient. The species displayed high physiological plasticity, a factor that might prove decisive in enhancing carbon fixation and water-use efficiency across the seasons, and accordingly its level of invasiveness. Temperature seemed crucial in controlling photosynthetic metabolism, a fact borne out by seasonal changes seen in δ13C and SI. Some stress symptoms appeared in winter, including a slight reduction of photochemical performance, and the shoreline–inland ecological gradient did not have any significant effects. All the plants analysed were intermediate C3–CAM: given that yucca cannot reproduce sexually in Europe, the entire population of the area studied might conceivably share the same carbon fixation pathway. The results obtained may help afford a better understanding of the ecophysiological features of Y. gloriosa in a Mediterranean dunal ecosystem, along with the dynamics of the invasion process, allowing a more efficient approach to be adopted in programmes for managing this environment