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While the ongoing global warming and the economic crisis threaten horticultural and ornamental products production in the Mediterranean region, new challenges and opportunities for renewing plant material occur. Pitaya has great potential as a new crop for Mediterranean growers: it consumes little water and it adapts well to the high temperatures present in the greenhouse. Moreover, the market shows increasing demand of new, healthy exotic fruits and the fruit of these crops are worldwide appreciated as a super fruits. The aim of this study was to investigate the potential of introducing a new type of product that in addition to the aesthetic value can combine functional nutritional characteristics, through a whole chain approach, in order to develop basic knowledges and technical information that may lead to the commercial production of pitaya by small-scale farmers in Italy. The results of this study report and discuss various aspects to support the establishment of pitaya cultivation, such as its propagation by cuttings and micropropagation, greenhouse cultivation practices (through the clarification of the sprouting and flowering phenology as well as the fruit maturation period), while providing also information on the sensory properties and the antioxidant levels which naturally occurring in these fruits.

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.

Potato is a source of different bioactive compounds, and the potato transformation industry produces conspicuous quantities of potato peels as waste. In this context, the objective of this research was twofold: (i) the evaluation of the recovery of bioactive compounds from organic potato byproducts through an innovative multistep green extraction process, (ii) to evaluate the preservation during storage of the main quality-physicochemical parameters of minimally processed apples treated with two different natural extracts obtained. The potato extracts were obtained by solid CO2 cryomaceration followed by solid/liquid extraction based on water or 10% ethanol/water solutions. The efficacy of potato extracts, with or without 1% of citric acid, was tested in comparison with traditional preserving compounds in minimally processed apple preparation. All the extracts were characterized by a high antioxidant power and were rich in phenol compounds, showing a good activity in keeping the qualitative parameters of fresh-cut apple. A significant anti-browning effect as well as a slowing down of the softening of fruits during storage were observed. The obtained results suggest the suitability of the potato extracts as antioxidant additives for fresh-cut fruits, thus avoiding the use of unsafe chemicals.

The in vitro rooting phase of Echinacea angustifolia DC. was studied through an unconventional approach, where micropropagated shoots from adult plants were grown under autotrophic conditions. The system employed artificial supports (cellulose plugs) soaked with a liquid sugar-less MS medium that contained 1 mg L−1 indole-3-butyric acid (microfloating). The culture vessels were provided with passive ventilation (PV) or forced ventilation (FV) by bubbling air into the liquid medium. Using this microfloating system, the E. angustifolia plantlets reached about 65% rooting capacity. The cultures were analyzed for their photosynthetic rates (PN), carbohydrate content and phytochemical profile. When the ventilation of the vessels was forced, the net photosynthetic rate was enhanced improving explant quality and survival during acclimatization, but the content of caffeic acid derivatives (CADs) was negatively affected. On the contrary, at the end of the multiplication phase in mixotrophic conditions, the photosynthesis was impaired and the production of CADs was improved. The mixotrophy or autotrophy status experienced by the E. angustifolia microplants during the micropropagation process can direct the cultures towards either the accumulation of active compounds or the production of good quality transplants suitable to undergo the acclimatization process.

Ultraviolet B (UV-B) radiation has been previously reported to induce changes in secondary metabolites such as phenolic compounds by improving, in particularly, the nutritional value of aromatic plants. This study aimed to evaluate the dynamic biological stress response of Ocimum basilicum L. plants exposed to different UV-B doses (8.5, 34, 68, 102 kJ m−2 day−1), delivered using three different experimental approaches (acute, sub-acute and sub-chronic), on phenolic compounds accumulation and chlorophyll a fluorescence parameters. Sweet basil plants were grown using a novel “in vivo-vitro system” in a closed-type plant production system that allowed the control of UV-B dose easily and accurately by switching on and off the supplemental UV-B lamps. Results suggest that the dynamic accumulation of phenolic compounds as well as the ability to maintain the structural organization of PSII and thus the leaf functionality were dependent on the biologically effective UV-B dose applied and the exposure-history of the plants. UV-B doses continuously (as a single exposure) applied significantly increased phenolics, but severely affected photosynthetic efficiency. Discontinuous UV-B-exposures either applied within a single day (sub-acute) or within 6 days (sub-chronic) yielded in general at the same dose, slightly amount of total phenolics but showed an improved potential to process light energy through PSII compared to continuous UV-B application. Our data suggest that an improved accumulation of phenolic compounds can be achieved when UV-B radiation is applied for long period, within six days, discontinuously, without affecting the efficiency of photosynthetic apparatus.

Iris spp. rhizomes are used in cosmetics and perfumery thanks to the presence of irones, violet-scented ketonic compounds. Between the several Iris species, Iris pallida Lam. is rich in irones and is the most valuable. In Tuscany, the cultivation of I. pallid is an integral part of the rural tradition. The aim of the research is to study the possibility of producing I. pallid plants by micropropagation and to overcome some critical factors of traditional cultivation. This study was based on the induction of somatic embryogenesis from flower buds and from leaf tissues of in vitro plantlets. Results demonstrated that the most suitable factors to begin the induction of embryogenic callus were the medium, a modified MS medium named i1B containing 0.1 mg L-1 Kinetin (Kin) and 1 mg L-1 2,4-dichlorophenoxy acetic acid (2,4-D), and the explant, the petal hafts (the base of the petals) of the flower buds. Another medium, named i1A, containing 1 mg L-1 Kin and 1 mg L-1 2,4-D was the most appropriate for the successive subcultures of the embryogenic callus among the tested ones. To induce and maintain embryo formation, an expression medium, named i2, containing a modified Knudson C macro elements, 1 mg L-1 Kin and 0.1 mg L-1 indole-3-butyric acid (IBA) was efficient. The protocol was subsequently improved with the use of in vitro microplant leaf tissues for the production of embryogenic callus. Transferring the embryos onto a modified MS medium named i3 with 0.1 mg L-1 of 6-benzyladenine (BA) and ?-naphthaleneacetic acid (NAA), allowed us to obtain microplants to acclimatize ex vitro. As regards the presence of irones precursors, the HPLC chromatographic profile of the rhizomes from micropropagated I. pallida plants after acclimatization in open field, was comparable to that of rhizomes from mother plants cultivated in the place of origin.

Ludwigia palustris (L.) Ell. is an aquatic perennial herb present in several regions of Italy, which is one of its native countries. In this research, micropropagation and encapsulation protocols were established from axillary buds of L. palustris. Shoots proliferated on half-strength Murashige and Skoog medium without growth regulators. Different culture vessels were tested. Shoots in GROWTEK bioreactor showed the highest fresh and dry weight and total length while the plantlets grown in the RITA bioreactor showed the highest shoot number per explant. Encapsulation of L. palustris microcuttings with sodium alginate formed small and whitish beads which were stored for 14 or 28 days at 7° or 25°C. Storage for 14 days at both temperatures gave the best results but prolonged storage at 25°C decreased the shoot viability to 73%. After 4 weeks of recovery, all the plantlets showed the typical features of the species. Even though the latest Italian IUCN Red List does not mention L. palustris, conservation measu...

The response of plants to salt stress involves dynamic changes in growth and signaling leading to successful adaptation or death. To elucidate how these opposed events are coordinated we identified a salt-tolerant (obesifruticosa) and a salt-sensitive (aestiva) Antirrhinum majus mutants using shoots as sensitive indicator of stress magnitude. A series of physiological tests were performed that compared the response after 6 h and 3 days of these contrasting mutants grown in agar under a single (200 mM) NaCl concentration, including shoot area, root length, relative water content, plant height, and overall biomass accumulation. Additional measurements of ABA content, chlorophyll degradation, ethylene production, net photosynthesis rates and Na+, K+, Ca2+, and Mg2+ content were also reported. RNA-seq analysis was performed on the two mutants after 6 h and 3 days under 200 mM NaCl. A total of 9199 transcripts were found to be differentially expressed in response to NaCl treatment in the two mutants. A large collection of known genes, including MAPKs, CDKs, CDPKs, CIPKs, various transcription factors, various ion transport proteins, and various genes involved in ABA and ethylene signaling pathways were described in detail that displayed differential expression profiles. Overall these data provided evidences of a putative osmotic tolerance sensing and signaling mechanism through a better integration and transduction of environmental cues into growth programs. The reprogramming of calcium-signaling components, generates specific stress signatures affecting differentially the salinity tolerance traits, such as tissue tolerance and anion exclusion. Interestingly, the hormones ABA and ethylene may action as a positive regulators of salt acclimation by the modulation of their signal transduction pathway.

There is a tremendous growing interest both in various industrial sectors and among people worldwide, towards the use of natural compounds from plant origin. The natural compounds obtained from plants have been more and more employed by cosmetic, food and pharmaceutical industries and could represent potential alternatives to synthetic chemicals. In the Lamiaceae family there are herbs with enormous socio-economic value, including several species of horticultural and ornamental interest, many used as culinary herbs, and with diversified industrial applications essentially due to their high content in valuable phenolic compounds. This review focuses on the wide spectrum of bioactive phenolic compounds in several species in the Lamiaceae , which possess known pharmacological properties and are used by humans for therapeutic purposes. It also reports other challenging and innovative industrial applications of these compounds as potential alternatives to conventional synthetic chemicals, because natural phenols would have lesser environmental and human health impacts than most of the conventional ingredients used in cosmetic, pesticides and food additives-preservatives industries. Finally, the review considers how an enhanced understanding of the effects of elicitation could be applied to increase and/or modify tissue content of active principles. Chemical or physical elicitors can activate the stress-signaling pathways leading to enhance the content of bioactive secondary metabolites, thus representing a new perspective for sustainable production of industrial crops.

The aim of the study was to examine the possibility of propagating in vitro four of the most common cultivars in Tuscany (central Italy): Terom, Violetto di Toscana, Chiusure and Empolese. The first three belong to the “Violetti” group, while cv Empolese belongs to the “Romaneschi” group. Explants were cultured on an induction medium (IM), which is a modified MS medium consisting of nitrate concentrations reduced by one quarter, 0.8 mg L−1 6-benzylaminopurine (BA) and 0.2 mg L−1 3-indole butyric acid (IBA). Explants were then transferred to a proliferation medium (PM) consisting of the same basal medium together with 0.03 mg L−1 BA and 0.05 mg L−1 gibberellic acid (GA3). A rooting double-phase was then established. The pre-rooting medium (PRM), consisting of a basal MS medium with half strength nitrate concentrations, 0.5 mg L−1 indole-3-acetic acid (IAA) and 1 mg L−1 paclobutrazol (PBZ) was used for two weeks. Over the next four weeks, a rooting medium (MR) was used, consisting of a basal MS medium with 2 mg L−1 β-cyclodextrin and 2 mg L−1 α-naphthaleneacetic acid sodium salt (NAA). The cv Empolese provided the highest number of proliferated explants and rooted plantlets using the method described.

The accumulation of selected caffeic acid derivatives (CADs), in particular rosmarinic acid (RA), was investigated in different tissues (leaves, roots and plantlet shoots) of sweet basil (Ocimum basilicum L.) plants grown either in vitro or in hydroponic culture (floating system) under greenhouse conditions. Two cultivars with green leaves (Genovese and Superbo) and one with purple leaves (Dark Opal) were tested. The content of CADs in HCl-methanol extracts was determined by HPLC. LC-MS and LC-MS-MS were used to confirm the identification of the metabolites of interest. Apart from rosmarinic acid (RA) and a methylated form of this substance, no other CADs were detected at significant level in any of the analyzed samples. The content of RA ranged approximately from 4 to 63 mg/g DW, depending on the growing system. The highest RA content was found during the in vitro multiplication, in the acclimatized plants and in the roots of hydroponically-grown seedlings at full bloom. In vitro, 6-benzyladenine reduced the accumulation of RA in purple-leaf Dark Opal cultivar, but an opposite effect of this growth regulator was observed in the green-leaf genotypes. Our findings suggest the possibility to scale-up RA production by means of in vitro or hydroponic culture of sweet basil.

The effects of different growth conditions (ventilated and closed vessels, medium with 0, 15 and 30 g dm−3 sucrose) during proliferation of donor quince (Cydonia oblonga Mill.) shoots (stage I) on net photosynthetic rate and soluble sugars content were evaluated. In order to assess the influence of these physiological parameters on morphogenesis, leaf explants harvested from donor shoots were induced to form somatic embryos and adventitious roots under ventilated and closed Petri dishes (stage II). Natural ventilation and low sucrose contents (0–15 g dm−3) promoted the photosynthetic rate of quince shoots whereas biomass accumulation was the highest in those shoots cultured with 30 g dm−3 sucrose in both vessel types and 15 g dm−3 sucrose under natural ventilation. Increasing sucrose content in the medium induced greater accumulation of sucrose in leaf tissues of donor shoots. The content of reducing sugars was higher than that of sucrose, and it appeared to be higher in shoots cultured under natural ventilation compared to those in closed vessels. Somatic embryogenesis and root regeneration were influenced by stage I and II treatments. A significant correlation between sucrose content in the leaves of donor shoots and the number of somatic embryos regenerated was found, suggesting that identification of biochemical and physiological characteristics of donor shoots associated with increased regeneration ability might be helpful for improving morphogenesis in plant tissue culture.

Cytisus aeolicus Guss. ex Lindl. (Fabaceae family, subfamily Faboideae) is an endangered endemic species of the Aeolian Islands, Sicily. In vitro multiplication of C. aeolicus shoots was described in this work and cell cultures were established from cotyledons and hypocotyls to investigate their potential production of isoflavones. Aseptically germinated seeds, cultivated on LS modified basal medium, gave the initial explants used both to induce axillary propagation and callus cultures. The LS (Linsmaier and Skoog) basal medium, supplemented with 0.1 mg L−1 of 6-benzylaminopurine were used to induce axillary propagation. The callus induction was performed using the basal medium added with 5 mg L−1 2,4-dichlorophenoxy acetic acid and 5 mg L−1 kinetin (control medium). Basal medium was also added with 2000 mg L−1 casein hydrolysate (CH) or 900 mg L−1myo-inositol (MI). C. aeolicus callus cultures on CH and MI media produced an unique compound, the isoflavone genistein 7-O-ß-D-glucopyranoside (genistin), which has not previously been isolated from wild plants. Callus cultures grown on the medium containing myo-inositol produced the greatest amount of genistin. C. aeolicus tissue culture procedures could provide suitable plant material both for germplasm preservation (by micropropagation) and for biotechnological selective isoflavone production (by callus culture).

In this work in vitro culture conditions for three species belonging to the Labiatae family were studied. In particular, a micropropagation protocol of Lavandino cv Grosso (Lavandula officinalis Chaix × Lavandula latifolia Villars) was developed. As regards this species it was verified that the hyperhydricity symptoms of axillary shoots were related to the agar concentration in the culture medium. Moreover, a reproducible in vitro propagation procedure was established for Mentha piperita L.. The results demonstrated that the method of supplying cytokinins affected the proliferation percentage. Moreover, studies concerning the influence of gravity on shoot formation showed that the perturbation of the explant orientation modified BA absorption inducing shoot hyperhydricity. Explants from wild plants of Ajuga reptans L. were micropropagated giving the source of material to start callus production: different callus proliferation and qualities were observed in dark and light conditions. The results from the experiments on the three species suggest that the interaction among physical- chemical factors may affect tissue cultured plants and it might often mask or give unexpected results generating mistakes in data evaluation.

Five in vitro culture systems with different ventilation rates were used to investigate the influence of vessel environment on photosynthesis, dark respiration, ethylene evolution, and rosmarinic acid (RA) production in sweet basil (Ocimum basilicum L.) micropropagated shoots. The systems under comparison were two bioreactors with either temporary (RITA™) or stationary (Growtek™) immersion, and three types of vessels (Magenta™, Microbox ECO 2 ™, and PCCV25™) that are largely used for plant micropropagation. Shoots of green-leaved cv. Genovese and purple-leaved cv. Dark Opal were cultured on a modified Murashige and Skoog medium containing 0.25 mg dm−3 6-benzylaminopurine. The instantaneous rates of photosynthesis, dark respiration, and ethylene production were determined by gas chromatography measuring CO2 and ethylene concentrations in vessel headspaces. The tissue RA content was determined by HPLC in HCl-methanol extracts. The explant growth and morphology were significantly affected by culture conditions and cultivars. The largest biomass production was observed under the photomixotrophic culture conditions provided by Growtek™, whereas the highest RA content in shoot tissues was found in the RITA™ photomixotrophic system, where ethylene accumulated to the greatest extent.

This chapter provides a short discussion about the opportunity to cultivate in vitro plant tissue of species which synthesize secondary metabolites of nutraceutical interest. The introduction of species of particular interest in cultivation and domestication, can be an alternative to the harvest of wild species. In vitro culture techniques are a useful tool to improve production and marketing nutraceutical species which allows to make a rapid clonal propagation of plants selected for their active principles. The techniques of tissue culture are described in detail. In particular, it is underlined the necessity to clone selected plants and produce true-type plants when standardized plant products are the main goal. This can be reached by conventional micropropagation protocols culturing plants in vitro through the five culture phases. Another approach consists in applying unconventional systems in the last phase of in vitro culture which permit to develop autotrophy of the explants. Autotrophic growth improves the quality of the multiplied shoots and facilitates the acclimatization of the plantlets.

The Iris genus includes about 300 species. Iris spp. rhizomes are used in cosmetics and perfumery thanks to the presence of irones, violet-sciented ketonic compounds. The rhizomes of the Italian Iris are much appreciated and requested by the perfume and cosmetics industries and are often preferred to those of other origins (Morocco, India, China). Among the different species of Iris, Iris pallida Lam. is the species most valuable and rich in irones. In Tuscany, the typical areas of cultivation of I. pallida are located on the hills of Chianti (Firenze) and Pratomagno (Arezzo). The technique of micropropagation, increasing the plant production for the Iris cultivation in the region of origin, might allow to obtain a greater amount of rhizomes to the extraction of aromatic essences. This study is based on the induction of somatic embryogenesis from tissues of I. pallida adult plants harvested in the endemic area of Pratomagno (Arezzo). In this work we have developed different types of sterilization procedures for I. pallida explants (rhizomes or immature flower buds). These explants were tested for different types of media to induce embryogenetic callus and the development of somatic embryos.

This chapter provides a short discussion about the opportunity to cultivate in vitro plant tissue of species which synthesize secondary metabolites of nutraceutical interest. The introduction of species of particular interest in cultivation and domestication, can be an alternative to the harvest of wild species. In vitro culture techniques are a useful tool to improve production and marketing nutraceutical species which allows to make a rapid clonal propagation of plants selected for their active principles. The techniques of tissue culture are described in detail. In particular, it is underlined the necessity to clone selected plants and produce true-type plants when standardized plant products are the main goal. This can be reached by conventional micropropagation protocols culturing plants in vitro through the five culture phases. Another approach consists in applying unconventional systems in the last phase of in vitro culture which permit to develop autotrophy of the explants. Autotrophic growth improves the quality of the multiplied shoots and facilitates the acclimatization of the plantlets.

The regeneration of shoots of Echinacea angustifolia DC. in vitro, using sections of flower stalks of open field E. angustifolia adult plants, was achieved. These sections produced the formation of shoots directly or from morphogenetic callus on a modified MS culture basal medium, named CH, supplemented with 0.5 mg L -1 6benzilamminopurine (BA). The in vitro proliferation was carried out using the same basal medium after two previous subcultures with 0.25 mg L -1 BA and active charcoal (5 mg L -1 ) without plant growth regulators. Callus cultures were also obtained from leaf segments cultured on CH basal medium with 3 mg L -1 BA and 0.5 mg L -1 indole-3butyric acid (IBA). The secondary metabolite content of the different plant material obtained from the in vitro cultures was defined. Caffeic acid derivatives (chlorogenic, caffeic, caftaric, cichoric acids and echinacoside) and alkamide [dodeca-2E,4E, 8Z,10E-tetraenoic acid isobuthylamide] (chosen as representative for the alkamides) were considered as markers for the quali-quantitative LC-DAD-ESI-MS analysis. In vitro shoots in different growth phases showed significant differences in the production of alkamides or caffeolquinic acid derivatives giving the possibility to select the plant material on the basis of its secondary metabolite content.

Tamarix gallica L. was micropropagated from four-to six-node explants taken from mature trees. Shoot proliferation was induced on Linsmaier and Skoog medium containing 30 g l-1 sucrose, 7 g l-1 agar, 200 mg l-1 reduced glutathione (basal medium) and supplemented with 3.3 μM benzyladenine. Adding 0.5 or 1.0 μM indole-3-butyric acid (IBA) to the basal medium increased lateral shoot formation and ease of rooting. Microcuttings repeatedly subcultured on 1.0 μM IBA produced well-developed roots, a high number of axillary shoots and could be acclimatized in the greenhouse.

The behaviour of myrtle (Myrtus communis L.) plantlets during the last phase of in vitro culture before transplanting was studied. Myrtle plants were sampled from Mediterranean shrubland vegetation. In vitro growth of myrtle microcuttings was evaluated during the rooting phase using 500 cm3 containers fitted with two different types of closures. The number of gas exchanges and time in which aerated and closed vessels lose half of their gas content were calculated. Both types of vessel closure allowed photosynthetic activity in myrtle cultures even though the higher aeration rate induced higher net photosynthetic rate (PN) during all the culture. In vitro morphogenetic and rooting of myrtle microcuttings were affected by the different environment conditions inside the culture vessels: plantlet growth and root formation of myrtle explants increased in aerated vessels in comparison with closed ones. The well developed root system, the higher PN and dry mass accumulation during the pre-acclimatization phase in aerated vessels induced a better ability to face the transplant stress.

The water relations and gas exchange parameters of Arbutus unedo, Cistus monspeliensis, Erica arborea, Myrtus communis, Phillyrea latifolia, Pistacia lentiscus, and Quercus ilex growing in the shrubland vegetation at the Parco Naturale della Maremma (Italy), were studied over two consecutive years. At high leaf water potentials, photosynthetic rates and stomatal conductance were relatively low in all species but C. monspeliensis. Stomatal conductance remained relatively high in C. monspeliensis leaves as soil moisture was depleted, whereas A. unedo, E. arborea, M. communis, and P. lentiscus were more conservative in water use. P. latifolia and Q. ilex showed a drought-tolerant behaviour.

The in vitro rooting of myrtle (Myrtus communis L.) plantlets was performed in containers with gas permeable (V) and non-permeable (C) closures characterized by a different number of gas exchanges (1.4 and 0.3 h− 1, respectively). The rooting was induced on Perlite, soaked with half strength Murashige and Skoog (MS) medium with 0.5 mg dm−3 IBA, either with and without 15 g dm−3 of sucrose. During the rooting phase, it was demonstrated that C cultures without sucrose (C−) negatively affect the growth of myrtle plantlets. The net photosynthetic rate and the starch content showed the lowest values in C cultures with and without sucrose (C+ and C−) while chlorophyll a content did not vary among treatments, therefore it could not be considered an indicative parameter to evaluate the autotrophic metabolism in myrtle plantlets. Electron microscopy and image analysis were employed to evaluate the leaf ultrastructure at three sample dates. Plantlet rooted in vented vessels with and without sucrose (V+ and V−) showed chloroplasts with numerous starch inclusions, while several osmiophilic plastoglobules (frequently related with leaf senescence) were found in chloroplast of leaf cells of C− myrtle plantlets.