CHARACTERIZATION OF BIOACTIVE COMPOUNDS AND QUALITY ATTRIBUTES IN VACCINIUM SPP. DURING DEVELOPMENT RIPENING AND STORAGE.

Blueberries belong to the genus Vaccinium , a widespread genus with over 200 species of evergreen and deciduous woody plants varying in size from dwarf shrubs to trees. Blueberry possesses one of the highest antioxidant capacities in berries due to the high contents of anthocyanin pigments; it is also a moderate source of ascorbic acid (AsA). It is accepted that the content of phenolics and ascorbic acid in berries is not only affected by genetic differences and pre-harvest environmental conditions, but also by the degree of maturity at harvest. In postharvest, different storage conditions may also strongly influence antioxidant capacity of this produce and there are many factors who contribute to improve fruit quality maintenance such as temperature, gas concentration and cultivar. The aim of these studies is to improve the product quality, by acquiring a better understanding about the evolution of bioactive compounds during maturation and storage and to define the optimal conditions to extend the shelf life of fresh produce while ensuring both commercial and nutraceutical quality. The work consists in the identification and evaluation of antioxidant compounds (such as phenolics and ascorbic acid) of potential use for their functional and bioactive properties during maturation and ripening and under different pre- and postharvest conditions in different blueberry cultivar and species. \uf0d8 Shelf-life trials were performed along three years in order to test different controlled atmosphere (C.A.) conditions on three blueberry varieties (\u2018Brigitta\u2019, \u2018Legacy\u2019 and \u2018Duke\u2019). Analyses on phenolic compounds and ascorbic acid content were performed, moreover, we performed analyses aiming to estimate the oxidative status of fruits during storage, by measuring the malondyhaldeide content expressed as TBARs equivalents. We have individuated the storage conditions that guarantee both the longest shelf life and the highest phenolic content during storage. Among the considered varieties, \u2018Brigitta\u2019 showed the best attitude to C.A. storage with the lowest degradation rate, and the highest quality keeping during the storage period. \uf0d8 Benzothiadiazole (BTH) is a functional analogue of salicylic acid that acts as an elicitor of the phenolic metabolism and of systemic acquired resistence (SAR). Pre-harvest treatments with BTH were performed on two different varieties (\u2018Duke\u2019 and \u2018Brigitta\u2019) during fruit development and ripening. We measured ascorbic acid content, total phenols, total anthocyanins and total flavonoids at four different stages of maturation and ripening. We also measured APX, DHAR, MDHAR and GR enzymatic specific activities. A substantial positive effect of BTH treatment on phenolics and ascorbic acid content was observed in blueberry with different behavior depending on the cultivar studied. A positive effect was also observed on the activity of the enzymes involved in ascorbate recycling. \uf0d8 Pre-harvest treatments using the phytohormone Methyl Jasmonate (MeJa) were performed. Plants from two cultivar (\u2018Blue Ray\u2019 and \u2018Duke\u2019) were treated with a MeJa solution. Berries nearly expanded after colour breaking were picked 3, 6, 9 and 24 hours after treatment for molecular analyses. After one week from the treatment all fruit from the plants were picked up and stored at -80\ub0C. The whole experimental plan was repeated for two growing seasons. Total RNA was extracted from tissues for gene expression analyses on key enzymes of the phenylpropanoid pathway. Our results showed that the treatment was effective in stimulating the expression of some of the key genes in phenylpropanoids metabolism (such as CHS and PAL). We measured the changes in levels of different classes of phenolic compounds by HPLC. Data obtained from transcripts and metabolite analyses resulted to be well-paralleled and allowed us to make comparisons and observe good correlations in the so called gene-to-metabolite networks for secondary metabolism in blueberry. However more detailed analyses, for example on the regulatory factors of this pathway remains to be performed as an interesting challenge for future analyses. \uf0d8 Ascorbic acid (AsA) accumulation and the expression of the genes encoding the enzymes of the main AsA biosynthetic and recycling routes as well as the activities of the enzymes involved in AsA recycling were investigated for the first time during the development and ripening of bilberry (Vaccinium Myrtillus) fruit. The results showed that the AsA level was highest in unripe green berries but decreased slightly during the maturation. This was supported by the expression data of the genes encoding the key enzymes in the main AsA biosynthetic route, particularly in the early ripening stages. Activities of the studied enzymes were mainly consistent with the AsA levels. In over-ripe berries, both AsA content and gene expression were markedly higher in skin than in pulp

Transcriptional Regulation in Rocket Leaves as Affected by Salinity

Salinity is one of the major abiotic stress causing yield losses and decreasing product quality. The beneficial effects of biostimulant products to enhance plant tolerance to abiotic stresses have been reported in several crops, but their mode of action is poorly understood. This work aims to better understand the effect of salt stress on wild rocket treated with a borage extract. The expression of some of the transcription factors (TFs) typically involved in salt stress response was studied within a 24 h period. Physiological parameters such as chlorophyll, chlorophyll a fluorescence, carotenoids, phenols, and anthocyanin were analyzed. Results obtained showed that salt stress induced a general increase in the expression levels of almost all TFs studied, whereas the treatment with the plant-base extract only induced an increase at specific time points. Moreover, the approach adopted allowed indagating the change in gene expression during time. Different pathways such as sugars metabolism, cuticular wax biosynthesis, and brassinosteroids signaling took part in plant responses

Postharvest application of hydrogen peroxide and salicylic acid differently affects the quality and vase life of cut rose (Rosa hybrida L.) petals and leaves

Rose represents an important product in the market of cut flowers. Its quality is related to visual appearance and is affected by oxidative stress and senescence. To maintain the quality and extend the product vase life, innovative technical solutions to be applied in postharvest are needed. In this work the effectiveness of hydrogen peroxide (H2O2) and salicylic acid (SA), was assessed on cut rose leaves and petals. Several physiological indicators of quality were studied, including chlorophyll content, chlorophyll a fluorescence, color, lipid peroxidation, phenolic compounds and anthocyanins. After 7 days of vase life 73.33% of untreated roses were not marketable anymore, while the percentage was lower in response to treatments (47.06% in SA and 25.53% in H2O2). The application of H2O2 induced a reduction in leaf chlorophyll and in the performance index which, at the end of the vase life decrease by 76% and 49% respectively. Consistently, the lipid peroxidation in leaves treated with H2O2 increased by a 53%. After 4 days of vase life, SA allowed maintaining higher levels of anthocyanins in petals compared to H2O2 and to controls. The results obtained allowed individuating different responses, depending on the treatment applied as well as on the plant organ

Effetto di trattamenti postraccolta sulla qualità e sulla vase life di rose (Rosa hybrida) recise

La rosa (Rosa hybrida) \ue8 tra le specie pi\uf9 importanti nel panorama mondiale dei fiori recisi. La sua vase life \ue8 abbastanza breve e varia da 6 a 10 giorni, a seconda delle condizioni di conservazione. La senescenza di fiori e foglie \ue8 il principale responsabile delle perdite di qualit\ue0 e influenza fortemente la commercializzazione di questa specie ornamentale. Lo scopo di questo lavoro \ue8 stato quello di valutare gli effetti dei diversi trattamenti sulla qualit\ue0 e durata postraccolta di rose recise. Le rose tagliate (fiori e foglie) sono state trattate per 24 ore con diverse classi di composti tra cui elicitori chimici (acido salicilico SA, benzotiadiazolo \u2013 BTH) e molecole di segnale (perossido di idrogeno). Durante la vase life, il colore dei fiori, i livelli di clorofilla e la fluorescenza della clorofilla a nelle foglie, sono stati monitorati in modo non distruttivo. Campionamenti di foglie e fiori sono stati effettuati alla raccolta (T0) e dopo 7 giorni (T7) di vase life a 25 \ub0 C (UR 55%) e su tali campioni sono stati misurati i livelli di perossidazione lipidica e di composti fenolici. I risultati preliminari hanno mostrato che i trattamenti con BTH hanno determinato una diminuzione pi\uf9 marcata del contenuto idrico e una lieve variazione nel colore del fiore. I trattamenti con BTH e SA hanno aumentato il contenuto di clorofilla nelle foglie dopo 7 giorni. Il perossido d\u2019idrogeno e l\u2019acido salicilico, hanno consentito di ottenere una minore percentuale di fiori danneggiati durante la vase life

Towards nutrition-sensitive agriculture : an evaluation of biocontrol effects, nutritional value, and ecological impact of bacterial inoculants

Nutrition-Sensitive Agriculture (NSA) is a novel concept in agriculture that considers not only yield, but also nutritional value of produce, sustainability of production, and ecological impact of agriculture. In accordance with its goals, NSA would benefit from applying microbial-based products as they are deemed more sustainable than their synthetic counterparts. This study characterized 3 plant-beneficial bacterial strains (Paenibacillus pasadenensis strain R16, Pseudomonas syringae strain 260-02, Bacillus amyloliquefaciens strain CC2) on their biocontrol activity and effect on nutritional and texture quality of romaine lettuce plants (Lactuca sativa) in greenhouse. The pathogens used in the trials are Rhizoctonia solani and Pythium ultimum. The obtained results indicate that strain R16 had a significant ability to cause a statistically significant reduction in the symptoms caused by both P. ultimum ( reduction of 32%) and R. solani (reduction of 42%), while the other two strains showed a less efficient biocontrol ability. Indices of the nutritional quality (content in phenols, carotenoids and chlorophyll) were unaffected by the treatments, indicating that the product was equivalent to that obtained without using the bacteria, while the texture of the leaves benefits from the biocontrol treatments. In particular, the mechanical resistance of the leaves was significantly higher in non-treated plants affected by R. solani but was restored to the values of healthy plants when the bacterial inoculants were present as well. The ecological impact was evaluated by characterizing the bacterial microbiota in bulk soil, rhizosphere, and root in the presence or absence of the inoculants. The composition of the microbiota, analyzed with a Unifrac model to describe beta-diversity, was radically different in the rhizosphere and the root endosphere among treatments, while the bulk soil formed a single cluster regardless of treatment, indicating that the use of these treatments did not have an ecological impact outside of the plant

Effect of Preharvest Abiotic Stresses on the Accumulation of Bioactive Compounds in Horticultural Produce

The quality of horticultural products is the result of the interaction of different factors, including grower\u2019s crop management ability, genotype, and environment. Sub-optimal environmental conditions during plant growth can induce abiotic stresses and reduce the crop performance with yield reduction and quality losses. However, abiotic stresses can induce several physiological, biochemical, and molecular responses in plants, aiming to cope with the stressful conditions. It is well known that these abiotic stresses are also elicitors of the biosynthesis of many metabolites in plants, including a wide range of bioactive compounds, which firstly serve as functional molecules for crop adaptation, but they have also a great interest for their beneficial effects on human health. Nowadays, the consumer is oriented to low-energy foods with low fat content, but at the same time, growing attention is paid to the presence of bioactive molecules, which are recognized as health-related compounds and concur to the nutraceutical value of plant-derived foods. In this context, fruit and vegetables play an important role as sources of bioactive ingredients in the diet. At the cultivation level, the understanding of crop responses to abiotic stresses and how they act in the biosynthesis/accumulation of these bioactive compounds is crucial. In fact, controlled abiotic stresses can be used as tools for improving the nutraceutical value of fruit and vegetables. This review focuses on the quality of vegetables and fruits as affected by preharvest abiotic stressors, with particular attention to the effect on the nutraceutical aspects

The effect of a complete fertilizer for leafy vegetables production in family and urban gardens

The home vegetables cultivation in family or urban gardens for self -consumption is mainly performed as a hobby but without following the good agricultural practices. Home gardening is often carried out by inexperienced people, which may lead to wrong fertilization. In this work, a fertilizer was evaluated for providing the mineral nutrients required from vegetables and stimulate the nutrient use efficiency in the plant. The commercial product ONE\uae, commercialized by Valagro S.p.A., was tested on two different leafy vegetables, Lactucasativa L. and Cichoriumendivia L. In order to discriminate the nutritional effect from the biostimulant effects, ONE\uae treatments were compared to a control added with the minimum crops requirements and to solutions containing the same concentrations of macro-nutrients as in ONE\uae. Results showed that ONE\uae treatments were able to speed up the growing rate of plants that reached the commercial maturity earlier. The chlorophyll content was higher in ONE\uae treatments, showing a positive effect on the visual appearance of the vegetables. Nitrate content in lettuce was below 500 mg/kg fresh weight, a value much lower than the commercialization law limits. Treatment caused a higher increase of reducing sugars in lettuce respect to endive. In lettuce the sucrose content was higher in outer leaves compared to the inner leaves, while opposite results were found for total sugars. In endive sucrose and total sugar were lower in ONE\uae treatments compared to control. In conclusion, considering yield and quality parameters, ONE\uae was effective in improving the quality of the leafy vegetables tested

Genetic and chemical comparison among Camelina sativa varieties

Camelina sativa (Camelina sativa L. Crantz.) belonging to the mustard family, typically contain about 40 % oil in the seeds, 90 % of which is made up of unsaturated fatty acids: about 30\u201340% fraction of alpha linolenic acid, 15\u201325% fraction of linoleic acid, 15% fraction of oleic acid and around 15% eicosenoic acid. Genetic studies of the genome of C. sativa suggest a polyploid structure being more probably a hexaploid species. In European countries and Russia, camelina was grown as an agricultural crop before the II World War; now the renewed interest on this crop is mainly due to the search for new sources of essential fatty acids, particularly n-3(omega-3) fatty acids to be used in human food and animal feed products. In this work we compared different varieties of camelina grown in different conditions: in experimental field, greenhouse and grow chamber. We characterized the genetic material by SSRs to assess the genetic diversity to assist future breeding programs. In particular we have set up a breeding program aimed at reducing the glucosinolate content in camelina seed because of its toxic effect when present at high levels in seeds used as feed. Glucosinolate are sulphur-containing glucosides, found mainly in Brassicaceae, involved in plant defense. In the last year these molecules have been studied also because of their activities as natural pesticides and their protective effects against cancer, heart disease and chronic inflammatory disease. We are now characterizing camelina seeds for glucosinolate content in order to develop a diagnostic marker based on the analytical determination of the sulfur isotopic signature (\uf06434S). Such a marker will allow to easily select genetic materials with different glucosinolate contents without the use of complex and expensive analytical techniques

Evaluation of borage extracts as potential biostimulant using a phenomic, agronomic, physiological and biochemical approach

Biostimulants are substances able to improve water and nutrient use efficiency and counteract stress factors by enhancing primary and secondary metabolism. Premise of the work was to exploit raw extracts from leaves (LE) or flowers (FE) of Borago officinalis L., to enhance yield and quality of Lactuca sativa ‘Longifolia,’ and to set up a protocol to assess their effects. To this aim, an integrated study on agronomic, physiological and biochemical aspects, including also a phenomic approach, has been adopted. Extracts were diluted to 1 or 10 mL L–1, sprayed onto lettuce plants at the middle of the growing cycle and 1 day before harvest. Control plants were treated with water. Non-destructive analyses were conducted to assess the effect of extracts on biomass with an innovative imaging technique, and on leaf photosynthetic efficiency (chlorophyll a fluorescence and leaf gas exchanges). At harvest, the levels of ethylene, photosynthetic pigments, nitrate, and primary (sucrose and total sugars) and secondary (total phenols and flavonoids) metabolites, including the activity and levels of phenylalanine ammonia lyase (PAL) were assessed. Moreover, a preliminary study of the effects during postharvest was performed. Borage extracts enhanced the primary metabolism by increasing leaf pigments and photosynthetic activity. Plant fresh weight increased upon treatments with 10 mL L–1 doses, as correctly estimated by multi-view angles images. Chlorophyll a fluorescence data showed that FEs were able to increase the number of active reaction centers per cross section; a similar trend was observed for the performance index. Ethylene was three-fold lower in FEs treatments. Nitrate and sugar levels did not change in response to the different treatments. Total flavonoids and phenols, as well as the total protein levels, the in vitro PAL specific activity, and the levels of PAL-like polypeptides were increased by all borage extracts, with particular regard to FEs. FEs also proved efficient in preventing degradation and inducing an increase in photosynthetic pigments during storage. In conclusion, borage extracts, with particular regard to the flower ones, appear to indeed exert biostimulant effects on lettuce; future work will be required to further investigate on their efficacy in different conditions and/or species

Short-term post-harvest stress that affects profiles of volatile organic compounds and gene expression in rocket salad during early post-harvest senescence

Once harvested, leaves undergo a process of senescence which shares some features with developmental senescence. These include changes in gene expression, metabolites, and loss of photosynthetic capacity. Of particular interest in fresh produce are changes in nutrient content and the aroma, which is dependent on the profile of volatile organic compounds (VOCs). Leafy salads are subjected to multiple stresses during and shortly after harvest, including mechanical damage, storage or transport under different temperature regimes, and low light. These are thought to impact on later shelf life performance by altering the progress of post-harvest senescence. Short term stresses in the first 24 h after harvest were simulated in wild rocket (Diplotaxis tenuifolia). These included dark (ambient temperature), dark and wounding (ambient temperature), and storage at 4 \ub0C in darkness. The effects of stresses were monitored immediately afterwards and after one week of storage at 10 \ub0C. Expression changes in two NAC transcription factors (orthologues of ANAC059 and ANAC019), and a gene involved in isothiocyanate production (thiocyanate methyltransferase, TMT) were evident immediately after stress treatments with some expression changes persisting following storage. Vitamin C loss and microbial growth on leaves were also affected by stress treatments. VOC profiles were differentially affected by stress treatments and the storage period. Overall, short term post-harvest stresses affected multiple aspects of rocket leaf senescence during chilled storage even after a week. However, different stress combinations elicited different responses