Yield Response and Physiological Adaptation of Green Bean to Photovoltaic Greenhouses.

The cultivation of the horticultural crops inside photovoltaic greenhouses (PVG) should be studied in relation to the shading cast by the photovoltaic (PV) panels on the roof. This work evaluated the green bean cultivation inside PVGs with a percentage of the greenhouse area covered with PV panels (PV cover ratio, PV R ) ranging from 25 to 100%. Three dwarf green bean cycles (Phaseolus vulgaris L., cv. Valentino) were conducted inside an iron-plastic PVG with a PV R of 50%. The average yield was 31% lower than a conventional greenhouse. Adverse effects on quality were noticed under the PV roof, including a reduction of pod weight, size, and caliber. Negative net photosynthetic assimilation rates were observed on the plants under the PV roof, which adapted by relocating more resources to the stems, increasing the specific leaf area (SLA), leaf area ratio (LAR), and the radiation use efficiency (RUE). The fresh yield increased by 0.44% for each additional 1% of cumulated PAR. Based on the linear regressions between measured yield and cumulated PAR, a limited yield reduction of 16% was calculated inside a PVG with maximum PV R of 25%, whereas an average yield loss of 52% can occur with a PV R of 100%. The economic trade-off between energy and green bean yield can be achieved with a PV R of 10%. The same experimental approach can be used as a decision support tool to identify other crops suitable for cultivation inside PVGs and assess the agricultural sustainability of the mixed system.

Emerging trends in the photodynamic inactivation (PDI) applied to the food decontamination.

The food and drink manufacturing industry is constantly seeking for alternative sanitation and disinfection systems that may achieve the same antimicrobial efficiency of conventional chemical sanitisers and at the same time be convenient in terms of energy and water savings. A candidate technology for this purpose is the use of light in combination with photosensitisers (PS) to generate a bioactive effect against microbial agents in a process defined as photodynamic inactivation (PDI). This technology can be applied to the food processing of different food matrices to reduce the microbial load of foodborne pathogens such as bacteria, fungi, viruses and protozoa. Also, the PDI can be exploited to increase the shelf-life period of food by inactivation of spoiling microbes. This review analyses new developments in the last five years for PDI systems applied to the food decontamination from foodborne pathogens. The photosensitisation mechanisms and methods are reported to introduce the applied technology against microbial targets in food matrices. Recent blue light emitting diodes (LED) lamp systems for the PDI mediated by endogenous PS are discussed as well PDI technologies with the use of exogenous PS from plant sources such as curcumin and porphyrin-based molecules. The updated overview of the most recent developments in the PDI technology both in wavelengths and employed PS will provide further points of analysis for the advancement of the research on new competitive and effective disinfection systems in the food industry.

Exogenous Application of Foliar Salicylic Acid and Propolis Enhances Antioxidant Defenses and Growth Parameters in Tomato Plants.

Salicylic acid (SA) and propolis (PR) are known to regulate the physiological process and to have a relevant role in bioactive compounds content. Our experiment was designed to evaluate the effect of SA and PR application on the growth, yield, and quality parameters of tomato grown for the fresh market in field conditions in Egypt. We studied the effect of twelve treatments where SA (0.50, 1.00, 1.50, 2.00, and 2.50 mM) and PR (1, 2, 10, 20, and 100 mg propolis mL-1) were applied at increasing doses as a sole agent or combined each other (1.50 mM + 10 mg mL-1 for SA and PR, respectively). An untreated control was also considered. Tomato plants treated with SA (0.50, 1.00, and 1.50 mM) showed a significant effect in all traits especially SA1 (0.50 mM) in growth parameters and SA2 (1.00 mM) in pigment and antioxidant content. Propolis foliar application was more effective than SA as it revealed that raising the concentration of aqueous extract enhanced the growth parameters and pigment in tomato. The best result was obtained by the 10 mg mL-1 treatment. The effect of propolis on antioxidant enzymes varied as the 10 mg mL-1 treatment was effective on peroxidases and superoxide dismutase, while 100 mg mL-1 was more effective on catalase. Salicylic acid and propolis have a positive effect on both preserving tomato plants and on nutrient supply, so the mixed intermediate concentration (1.50 mM + 10 mg mL-1) is considered very effective and results in an improvement of all plant traits.

Energy and environmental performances of hybrid photovoltaic irrigation systems in Mediterranean intensive and super-intensive olive orchards.

Over the last decades, traditional olive production has been converted to intensive and super-intensive cultivation systems, characterized by high plant density and irrigation. Although this conversion improves product quality and quantity, it requires a larger amount of energy input. The new contributions in this paper are, first, an analysis of the energy and environmental performance of two commercial-scale high peak-power hybrid photovoltaic irrigation systems (HPVIS) installed at intensive and super-intensive Mediterranean olive orchards; second, an analysis of PV hybrid solutions, comparing PV hybridization with the electric power grid and with diesel generators; and finally, a comparison of the environmental benefits of HPVIS with conventional power sources. Energy and environmental performances were assessed through energy and carbon payback times (EPBT and CPBT). The results show EPBT of 1.98 and 4.58 years and CPBT of 1.86 and 9.16 years for HPVIS in Morocco and Portugal, respectively. Moreover, the HPVIS were able to achieve low emission rates, corresponding to 48 and 103 g CO2e per kWh generated. The EPBT and CPBT obtained in this study were directly linked with the irrigation schedules of the olive orchards; therefore, weather conditions and irrigation management may modify the energy and environmental performances of HPVIS. The consumption of grid electricity and diesel fuel, before and after the implementation of HPVIS, was also analyzed. The results obtained show fossil energy savings of 67% for the Moroccan farm and 41% for the Portuguese installation. These savings suggest that the energy produced by HPVIS in olive orchards will avoid the emissions of a large amount of greenhouse gas and the exploitation of natural resources associated with fossil fuel production.

Climate change adaptation and water saving by innovative irrigation management applied on open field globe artichoke.

The setting up of innovative irrigation water management might contribute to the mitigation of negative issues related to climate change. Our hypothesis was that globe artichoke irrigated with a traditionally drip system could be converted to an innovative water management system based on precision irrigation techniques and on evaporative cooling application in order to improve crop physiological status with positive impacts on earliness, total heads yield and water saving. Over two experiments carried out at plot- and field-scale, two irrigation management systems, differing in type and application time, were compared: (i) conventional, and (ii) canopy-cooling. Plant physiological status at a weekly sampling interval and the head atrophy incidence (as the ratio of the total primary heads collected) were monitored. We also recorded and determined heads production, and yield components. In both experiments, throughout the application period of evaporative cooling (three months), canopy-cooling showed the lowest value of leaf temperature and the highest photosynthesis values compared with the conventional one (+3 °C and -30%, respectively). The physiological advantage gained by the crop with evaporative cooling has led to a higher production both in terms of total yield (+30%), and in terms of harvested first order heads that from an economic viewpoint are the most profitable for farmers. At farm-scale, the canopy-cooling treatment resulted in a higher earliness (35 days) and water productivity (+36%) compared with conventional one. Our findings show that by combining evaporative cooling practice with precision irrigation technique the heads yield can be optimized also leading to a relevant water saving (-34%). Moreover, the study proved that canopy-cooling set up might be a winning strategy in order to mitigate climatic changes and heat stress conditions.

Effects of alternative cropping systems on globe artichoke qualitative traits.

BACKGROUND: Traditionally, globe artichoke cultivation in the Mediterranean basin is based on monoculture and on use of high amounts of nitrogen fertiliser. This raises issues regarding its compatibility with sustainable agriculture. We studied the effect of one typical conventional (CONV) and two alternative cropping systems [globe artichoke in sequence with French bean (NCV1), or in biannual rotation (NCV2) with cauliflower and with a leguminous cover crop in inter-row spaces] on yield, polyphenol and mineral content of globe artichoke heads over two consecutive growing seasons. RESULTS: NCV2 showed statistical differences in terms of fresh product yield with respect to the monoculture systems. In addition, the dihydroxycinnamic acids and dicaffeoylquinic acids of non-conventional samples were one-fold significantly higher than the conventional one. All the samples reported good mineral content, although NCV2 achieved a higher Fe content than conventional throughout the two seasons. After two and three dates of sampling, the CONV samples showed the highest levels of K content. CONCLUSION: In our study, an acceptable commercial yield and quality of 'Spinoso sardo' were achieved by shifting the common conventional agronomic management to more sustainable ones, by means of an accurate choice of cover crop species and rotations introduced in the systems. © 2017 Society of Chemical Industry.

Organic carbon pools and soil biological fertility are affected by land use intensity in Mediterranean ecosystems of Sardinia, Italy.

Soil quality is mainly studied from the chemical and physical point of view, whereas soil biochemical and microbiological parameters are relatively more scarcely explored to assess the effect of management practices. This study aimed to evaluate soil organic carbon (SOC) and its pools; soil microbial activity parameters; and the Biological Fertility Index (BFI), in six land uses characteristics of the Mediterranean basin in north-eastern Sardinia. These land uses differed in management intensity and consisted of: tilled vineyard (TV), no tilled grassed vineyard (GV), former vineyards (FV), hay crop and pasture (HC and PA), cork oak forest (CO). Significant differences among ecosystems were found in most cases in (SOC), the related pools (total extractable carbon, humic and fulvic acids, not humified, not extractable), humification parameters (degree, rate and index of humification), and soil microbial activity (microbial carbon, respiration, metabolic quotient, and mineralization quotient). Pasture and cork oak forest showed in average a better soil quality for most biochemical and microbial parameters in comparison with the other ecosystems. The index of soil biological fertility (BFI) was higher under cork oak forest which is supposed to be the most sustainable ecosystem in the long term in this environment, able to maintain soil biological fertility and microbial diversity.

Soil bacterial community response to differences in agricultural management along with seasonal changes in a Mediterranean region.

Land-use change is considered likely to be one of main drivers of biodiversity changes in grassland ecosystems. To gain insight into the impact of land use on the underlying soil bacterial communities, we aimed at determining the effects of agricultural management, along with seasonal variations, on soil bacterial community in a Mediterranean ecosystem where different land-use and plant cover types led to the creation of a soil and vegetation gradient. A set of soils subjected to different anthropogenic impact in a typical Mediterranean landscape, dominated by Quercus suber L., was examined in spring and autumn: a natural cork-oak forest, a pasture, a managed meadow, and two vineyards (ploughed and grass covered). Land uses affected the chemical and structural composition of the most stabilised fractions of soil organic matter and reduced soil C stocks and labile organic matter at both sampling season. A significant effect of land uses on bacterial community structure as well as an interaction effect between land uses and season was revealed by the EP index. Cluster analysis of culture-dependent DGGE patterns showed a different seasonal distribution of soil bacterial populations with subgroups associated to different land uses, in agreement with culture-independent T-RFLP results. Soils subjected to low human inputs (cork-oak forest and pasture) showed a more stable bacterial community than those with high human input (vineyards and managed meadow). Phylogenetic analysis revealed the predominance of Proteobacteria, Actinobacteria, Bacteroidetes, and Firmicutes phyla with differences in class composition across the site, suggesting that the microbial composition changes in response to land uses. Taken altogether, our data suggest that soil bacterial communities were seasonally distinct and exhibited compositional shifts that tracked with changes in land use and soil management. These findings may contribute to future searches for bacterial bio-indicators of soil health and sustainable productivity.

Water deficit and induction of summer dormancy in perennial Mediterranean grasses.

BACKGROUND AND AIMS: Summer dormancy is a trait conferring superior drought survival in Mediterranean perennial grasses. As the respective roles of environmental factors and water deficit on induction of summer dormancy are unclear, the effect of intense drought were tested under contrasting day lengths in a range of forage and native grasses. METHODS: Plants of Poa bulbosa, Dactylis glomerata 'Kasbah' and Lolium arundinaceum 'Flecha' were grown in pots (a) from winter to summer in a glasshouse and subjected to either an early or a late-spring drought period followed by a summer water deficit and (b) in controlled conditions, with long days (LD, 16 h) or short days (SD, 9 h) and either full irrigation or water deficit followed by rehydration. Leaf elongation, senescence of aerial tissues and dehydration of basal tissues were measured to assess dormancy. Endogenous abscisic acid (ABA) in basal tissues was determined by monoclonal immunoassay analysis. KEY RESULTS: Even under irrigation, cessation of leaf elongation, senescence of lamina and relative dehydration of basal tissues were triggered only by a day length longer than 13 h 30 min (late spring and LD) in plants of Poa bulbosa and Dactylis glomerata 'Kasbah' which exhibit complete dormancy. Plants of Lolium arundinaceum 'Flecha' maintained leaf growth under irrigation irrespective of the day length since its dormancy is incomplete. ABA concentrations were not higher during late-spring drought than early, and could not be associated with spring dormancy induction. In summer, ABA concentration in bulbs of the desiccation-tolerant Poa were greater than in basal tissues of other species. CONCLUSIONS: The results of both experiments tend to invalidate the hypothesis that water deficit has a role in early summer-dormancy induction in the range of tested grasses. However, a late-spring drought tends to increase plant senescence and ABA accumulation in basal tissues of forage grasses which could enhance summer drought survival.

A proteomic characterization of water buffalo milk fractions describing PTM of major species and the identification of minor components involved in nutrient delivery and defense against pathogens.

Water buffalo has been studied in relation to the exclusive use of its milk for the manufacture of high-quality dairy products. Buffalo milk presents physicochemical features different from that of other ruminant species, such as a higher content of fatty acids and proteins. We report here a detailed proteomic analysis of buffalo skim milk, whey and milk fat globule membrane fractions. Notwithstanding the poor information available on buffalo genome, identification of protein isoforms corresponding to 72 genes was achieved by a combined approach based on 2-DE/MALDI-TOF PMF and 1-DE/muLC-ESI-IT-MS-MS. Major protein components, i.e. alpha(Sl)-, alpha(S2)-, beta-, kappa-caseins, alpha-lactalbumin and beta-lactoglobulin, were characterized for PTM, providing a scientific basis to coagulation/cheese making processes used in dairy productions. Minor proteins detected emphasized the multiple functions of milk, which besides affording nutrition to the newborn through its major components, also promotes development and digestive tract protection in the neonate, and ensures optimal mammary gland function in the mother. Defense against pathogens is guaranteed by an arsenal of antimicrobial/immunomodulatory proteins, which are directly released in milk or occur on the surface of secreted milk-lipid droplets. Proteins associated with cell signaling or membrane/protein trafficking functions were also identified, providing putative insights into major secretory pathways in mammary epithelial cells.

A widespread picture of the Streptococcus thermophilus proteome by cell lysate fractionation and gel-based/gel-free approaches.

Among the group of lactic acid bacteria, Streptococcus thermophilus has found a wide application in industrial processes used for the manufacture of dairy products. Taking advantage of different proteome extraction and subfractionation protocols, bacterial cytosolic and membrane proteins were isolated and resolved by independent gel-free and gel-based separation procedures. Whole cytosolic fraction and its acid, basic and low molecular mass protein components were separated by different resolutive 2-DE and tricine 1-DE gels and identified by MALDI-TOF PMF and/or microLC-ESI-IT-MS/MS. Membrane proteins were resolved by 2-DE and SDS-PAGE gels and similarly identified by PMF and TMS analysis. In parallel, whole extract was trypsinized and resulting peptides were identified by shotgun 2-D LC-ESI-IT-MS/MS analysis. Using this combined approach, expression products corresponding to 458 different genes were identified, which cover almost a third of the predicted vegetative proteome. Relative protein concentration and hydrophobicity affected protein detection. Broad recognition was obtained for enzymes involved in carbohydrate, fatty acid, amino acid and nucleotide metabolism, replication, transcription, translation, cell wall synthesis, as well as for proteins affecting bacterial functions important for industrial applications, i.e. milk sugar import and exopolysaccharide biosynthesis. By providing detailed reference electrophoretic/chromatographic maps to be used in future comparative proteomic investigations on bacteria grown under various experimental conditions or on different bacterial strains, our results will favour dedicated studies on S. thermophilus metabolism and its regulation or on detection of biomarkers for selection of optimal strains for industrial applications.

A study of Streptococcus thermophilus proteome by integrated analytical procedures and differential expression investigations.

Streptococcus thermophilus is a Gram-positive bacterium belonging to the group of lactic acid bacteria, among which several genera play an essential role in manufacture of food products. Recently, a genomic consortium sequenced and annotated its entire genome, which has been demonstrated to contain 1900 coding sequences. In this study, we have revealed the expression products of almost 200 different genes using a proteomic strategy combining 2-DE plus MALDI-TOF PMF and differential 1-DE plus muLC-ESI-IT-MS/MS. Thus, a number of cellular pathways related to important physiological processes were described at the proteomic level. Almost 50 genes were related to multiple electrophoretic species, whose heterogeneity was mainly due to variability in pI values. A 2-DE reference map obtained for lactose-grown cells was compared with those obtained after heat, cold, acid, oxidative and starvation stresses. Protein up/down-regulation measurements demonstrated that adaptation to different environmental challenges may involve the contribution of unique as well as combined physiological mechanisms. Common regulatory sites in the promoter region of genes whose expression was induced after stress were identified. These results provide a better comprehension of biochemical processes related to stress resistance in S. thermophilus, allowing defining the molecular bases of adaptative responses or markers for the identification of strains with potential industrial applications.

Comparative proteomic analysis of mammalian animal tissues and body fluids: bovine proteome database.

Characterizing the complete proteome of multicellular organisms is a challenging task using the currently available technologies. With the increasing degree of genetic complexity, animals acquire a broader repertoire of options to meet environmental challenges. Mammalian cells from different tissues/body fluids express different thousands of proteins with a predicted dynamic range of up to five to six orders of magnitude, thus necessitating the whole arsenal of dedicated analytical strategies for a detailed proteome characterization. Nevertheless, 2D-E analysis of whole cellular lysates still remains the most used initial approach for the proteomic description of specialized cells. It enables to obtain an overview of the main soluble protein components of a specific tissue/body fluid, allowing comparison between different cellular types and molecular description of organ specialization. Massive proteomic investigations have been reported mainly in the case of human, mouse and rat, allowing comparative analysis. For this reason, a research project focused on the 2D-E characterization of tissues and biological fluids from other domestic mammals has been undertaken in our laboratory. A number of high-resolution reference electrophoretic maps have been established for liver, kidney, muscle, plasma and red blood cells samples from Holstein Friesian bovine female individuals. Among the 1863 distinct protein features detected, 534 species were identified and associated to 209 different genes by a combination of MALDI-TOF mass fingerprint, capillary LC-ESI-IT-MS-MS and image gel matching procedures. Identified polypeptide species and differences in expression profiles between various tissues/fluids clearly reflected organ biochemical specialization. This experimental output allowed establishing a 2D-E bovine database accessible at the URL address for image comparison.

Differential proteomic analysis in the study of prokaryotes stress resistance.

Proteomic technologies are powerful tools to study the physiological response of bacteria to various environmental stress conditions. Complex protein toolkits coordinated by regulatory networks have evolved to accommodate bacterial survival under several stressing conditions, such as varying temperature or pH, and changes in nutrient availability. This manuscript provides an overview of the major achievements obtained by 2D gel based and non-gel based proteomic approaches for the study of adaptive response in bacteria. As an example, a study carried out on Streptococcus thermophilus response to various stresses is here reported. In this investigation, we used combined proteomic strategies to define proteomic maps useful to highlight protein profile variations following environmental challenges.

Proteins from bovine tissues and biological fluids: defining a reference electrophoresis map for liver, kidney, muscle, plasma and red blood cells.

A number of high resolution two-dimensional electrophoresis (2-DE) reference maps for bovine tissues and biological fluids have been determined for animals in basal state. Among the 1863 distinct protein features detected in samples of liver, kidney, muscle, plasma and red blood cells, 509 species were identified and associated to 209 different genes. Difficulties in the identification were related to the poorly characterized Bos taurus genome and were solved by a combined matrix-assisted laser desorption/ionisation-mass spectrometry and liquid chromatography-electrospray ionization tandem mass spectrometry approach. The experimental output allowed us to establish a 2-DE database accessible through the World Wide Web network at the URL address (http://www.iabbam.na.cnr.it/Biochem). These reference maps may serve as a tool in future veterinary medical studies aimed at the evaluation of changes in protein repertoire for altered animal physiological conditions and infectious diseases, to the definition of molecular markers for novel diagnostic kits and vaccines, as well as the characterization of protein modifications in bovine materials following technological processes used in the food industry.

Nuclear localization of Galectin-3 in transformed thyroid cells: a role in transcriptional regulation.

The differential proteomic approach (2D gel analysis coupled to MALDI-MS analysis) of nuclear proteins can provide an extremely useful tool to understand control of cell proliferation and differentiation. In order to identify possible markers of dedifferentiation between normal and cancerous thyroid cells, we used a differential proteomics approach by comparing nuclear extracts from the normal rat thyroid cell line FRTL-5 and the completely undifferentiated Ki-mol cell line, obtained by transformation with the Ki-ras oncogene. Galectin-3 (Gal-3) was identified as highly expressed, in the nuclear compartment, only in the transformed cell line. By using different human cancer cell lines, we showed that Gal-3 is maximally expressed in nuclei of papillary cancer cells. We focused on the functional relationship existing between Gal-3 and the thyroid-specific transcription factor TTF-1, whose expression is maintained in papillary cancer where it can contribute to the proliferating status. By using gel-retardation and transient tranfection assays, we demonstrate that Gal-3 upregulates the TTF-1 transcriptional activity. GST-pulldown experiments demonstrate the occurrence of interaction between Gal-3 and TTF-1 homeodomain. Since several lines of evidence suggest a role for Gal-3 in controlling proliferation and tumor progression in thyroid cancer, the stimulatory activity played by Gal-3 over TTF-1 would account for a possible molecular mechanism through which the galectin controls proliferation in thyroid cells.