Spatial and temporal distribution of mineral nutrients and sugars throughout the lifespan of Hibiscus rosa-sinensis L. flower

Although the physiological and molecular mechanisms of flower development and senescence have been extensively investigated, a whole-flower partitioning study of mineral concentrations has not been carried out. In this work, the distribution of sucrose, total reducing sugars, dry and fresh weight and macro and micronutrients were analysed in Hibiscus rosa-sinensis L. petals, stylestigma including stamens and ovary at different developmental stages (bud, open and senescent flowers). Total reducing sugars showed the highest value in petals of bud flowers, then fell during the later stages of flower development whereas sucrose showed the highest value in petals of senescent flowers. In petals, nitrogen and phosphorus content increased during flower opening, then nitrogen level decreased in senescent flowers. The calcium, phosphorus and boron concentrations were highest in ovary tissues whatever the developmental stage. Overall, the data presented suggests that the high level of total reducing sugars prior the onset of flower opening contributes to support petal cells expansion, while the high amount of sucrose at the time of petal wilting may be viewed as a result of senescence. Furthermore, this study discusses how the accumulation of particular mineral nutrients can be considered in a tissue specific manner for the activation of processes directly connected with reproduction

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

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

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

UV-B Physiological Changes Under Conditions of Distress and Eustress in Sweet Basil

UV-B radiation has been previously reported to induce protective or deleterious effects on plants depending on the UV-B irradiation doses. To elucidate how these contrasting events are physiologically coordinated, we exposed sweet basil plants to two UV-B doses: low (8.5 kJ m-2 day-1, 30 min exposure) and high (68 kJ m-2 day-1, 4 h exposure), with the plants given both doses once continuously in a single day. Physiological tests during and after both UV-B exposures were performed by comparing the stress-induced damage and adverse effects on photosynthetic activity, the concentration and composition of photosynthetic and non-photosynthetic pigments, and stress-related hormones biosynthesis in basil plants. Our results showed that upon receiving a high UV-B dose, a severe inactivation of oxygen evolving complex (OEC) activity at the PSII donor side and irreversible PSII photodamage caused primarily by limitation of the acceptor side occurred, which overloaded protective mechanisms and finally led to the death of the plants. In contrast, low UV-B levels did not induce any signs of UV-B stress injuries. The OEC partial limitation and the inactivation of the electron transport chain allowed the activation of photoprotective mechanisms, avoiding irreversible damage to PSII. Overall results indicate the importance of a specific response mechanisms regulating photoprotection vs irreversible photoinhibition in basil that were modulated depending on the UV-B doses

Effects of Nonthermal Plasma (NTP) on the Growth and Quality of Baby Leaf Lettuce (Lactuca sativa var. acephala Alef.) Cultivated in an Indoor Hydroponic Growing System

The aim of this research was to develop an effective protocol for the application of nonther-mal plasma (NTP) technology to the hydroponic nutrient solution, and to investigate its effects on the growth and quality of baby leaf lettuce (Lactuca sativa var. acephala Alef.) grown in a hydroponic growing system (HGS) specifically designed for indoor home cultivation. Four HGSs were placed in separate growth chambers with temperature of 24 ± 1◦ C and relative humidity of 70 ± 5%). Lettuce plants were grown for nine days in nutrient solutions treated with NTP for 0 (control) to 120 s every hour. Results of the first experiments showed that the optimal operating time of NTP was 120 s h−1 . Fresh leaf biomass was increased by the 60 and 120 s NTP treatments compared to the control. Treating the nutrient solution with NTP also resulted in greater leaf content of total chloro-phylls, carotenoids, total phenols, and total antioxidant capacity. NTP also positively influenced chlorophyll a fluorescence in Photosystem I (PSI) and photosynthetic electron transport. These results revealed that the NTP treatment of the nutrient solution could improve the production and quality of hydroponically grown baby leaf lettuce

The residues of fruit and vegetable pro-cessing: From “waste” to “resource” of natural phytochemical compounds

The project of Sant’Anna School, in line with the Italian legislation on limiting waste and promoting the redistribution of surpluses and unused goods, aimed to study the potential healthy value of residues obtained from the trans-formation of fruit and vegetable products that represent a cost, as they must be handled, stored and disposed according to stringent actual regulations. Two “model” species (potato and apple) were considered to test the possibility of using industrial processing waste for food applications. The extracts, obtained with “green” methods from potato and apple peels, were evaluated as natural antioxidants in the preparation of minimally processed fresh­cut apple. Results suggest the possibility to use these novel byproduct extracts as valuable alter-native treatments to traditional chemical additives employed for minimally processed apples

Relations of power driving tropical deforestation: a case study from the Mau Forest (Kenya) = Relations de pouvoir entraînant la déforestation tropicale : une étude de cas dans la forêt Mau (Kenya)

The paper investigates the deforestation process in the Mau Forest (Kenya), highlighting the actors involved and the underlying relations of power. The proximate causes of the deforestation are three: agriculture, wood production and infrastructures. In this context of pressure on natural resources, local communities have developed different projects to reduce deforestation and promote alternative development strategies, especially through the Community Forest Associations (CFAs). These dynamics show that deforestation is a complex issue whose solutions lie primarily outside the forest itself and that it should be tackled with suitable policies on crucial issues such as land, agriculture, infrastructure and indigenous peoples.L\u2019article analyse le processus de d\ue9forestation dans la For\ueat Mau (Kenya) et met l\u2019accent sur les acteurs impliqu\ue9s et les relations de pouvoir sous-jacentes. Les causes directes de la d\ue9forestation sont trois : l'agriculture, la production de bois et les infrastructures. Dans ce contexte de pression sur les ressources naturelles, les communaut\ue9s locales ont d\ue9velopp\ue9 diff\ue9rents projets visant \ue0 r\ue9duire la d\ue9forestation et \ue0 promouvoir des strat\ue9gies de d\ue9veloppement alternatives, en particulier \ue0 travers l\u2019action des Associations Communautaires de gestion de la For\ueat (CFAs). Ces dynamiques montrent que la d\ue9forestation est une question complexe dont les solutions se situent principalement en dehors de la for\ueat et devraient \ueatre abord\ue9es \ue0 travers des politiques appropri\ue9es sur des questions cruciales telles que la terre, l'agriculture, les infrastructures et les peuples autochtones

Effect of vitamin E for preventing Leucospermum leaf dissection during transportation

Leucospermum plants are commercialized with complex immature floral structures that would normally be rapidly growing and strong sinks for nutrient influx. The source/sink properties of Leucospermum plants clearly do change during different developmental stage and are very critical to the optimal development of the whole plants during post-production stage. During storage and transport, Leucospermum flowering potted plants are often damaged and the quality compromised. In fact, these post-production stages are usually characterized by sub-optimal environmental conditions (in particular the temperature and the light) leading to impair the photosynthetic machinery and activating a progressive leaf desiccation disorder. The post-production performance of ornamental potted plants can be preserved using optimal environmental conditions and additionally by applying appropriate chemical preservative treatments. In the present study was established the effects of double pre-transport/post-transport applications of chitosan and vitamin E on quality and physiological traits of Leucospermum potted flowering plants during the recovery phase. Plants were stored in growth chamber at 14 \ub0C with 70\u201380% relative humidity in the dark for four days to simulate transport conditions. Subsequently, plants were transferred in greenhouse for recovery ability evaluation under natural environmental conditions. Flowering potted plants were treated twice with 100 \u3bcM vitamin E and chitosan, the first was performed the day before the simulation of transportation and the second ones were carried out as soon as the plants arrived to the greenhouse of retails. The experiment was carried on by including two different controls: non-treated plants-not exposed to the transport simulation, and non-treated plants-subjected to the transport simulation. The findings of this experiment show that vitamin E applications have a positive effect on postproduction quality in Leucospermum, even a better performance compared to the non-transported control plants. The effect of vitamin E is mainly due to the antioxidant ability and the preservation of membrane stability. In contrast, the use of chitosan coating by the application of an invisible sprayed-film throughout the whole plants accelerated the leaf desiccation disorder during the same recovery period