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The intensive application of agro-chemicals, and in particular of copper (Cu)-based compounds, causes increasing pollution of agricultural land, with serious risks for human health. Aromatic plants used for purposes other than food, can be considered for the exploitation and/or remediation of metal-polluted substrates, since contamination of the essential oils by these metals was not significant. Myrtle (Myrtus communis L.) is a Mediterranean evergreen shrub whose essential oil has many commercial applications. In this work, the effect of an excess of Cu in respect to control conditions was assessed on M. communis growth and foliar terpene composition. Metal accumulation in roots and shoots was also evaluated for the possible use of this species in phytoremediation. The amount of Cu applied in our experiments minimally affected the terpene profiles of in vitro grown plants, whereas no variations were detected in in vivo plants. The presence of the metal in the soil did not significantly impair plant growth, thus allowing its cultivation on polluted substrates. On the other hand, the amount of Cu in the plant was not enough to result in a significant reduction of Cu levels in the soil. Therefore, myrtle plants proved to be good candidates for the re-vegetation of Cu-contaminated lands.

The characterization of behavioural cues involved in the location of a host-plant by a phytophagous insect allows the elaboration of tools that can be exploited in the sustainable protection of cultivated plants. In this context, the identification of the blend of Volatile Organic Compounds (VOCs) released by a host plant can be profitably used for diverting pest insects away from it and towards specific targets (plants, traps). Philaenus spumarius, the main vector of Xylella fastidiosa, i.e., the pathogen bacterium responsible for the Olive Quick Decline Syndrome (OQDS), moves to olive trees when the grass cover dries up. To date, the possible role of chemical cues regulating this passage is not known. Moreover, it is still to be tested whether VOCs are involved in the resistance to the bacterium recorded in two olive varieties, namely FS-17 and Leccino. To verify these hypotheses, we characterized the behavioural response of P. spumarius towards the two resistant (Leccino, FS-17) and three common susceptible olive trees varieties (Ogliarola, Frantoio and Rotondella) in olfactometer bioassays. The response of P. spumarius towards olive varieties was sex-dependent: males were totally unresponsive whilst females were attracted by Ogliarola, Rotondella and Frantoio, and repelled by FS-17. No preference was recorded when testing females against Leccino and clean air. The characterization and the quantification of the VOCs released by the olive varieties tested supported the behavioural observations and paved the way to discuss their possible role in the elaboration of integrated protocols for the sustainable protection of olive trees from the deadly expansion of X. fastidiosa.

Main conclusion Dissimilar patterns of variants affecting genes involved in response to herbivory, including those leading to difference in VOC production, were identified in tomato lines with contrasting response to Tuta absoluta. Abstract Tuta absoluta is one of the most destructive insect pest affecting tomato production, causing important yield losses both in open field and greenhouse. The selection of tolerant varieties to T. absoluta is one of the sustainable approaches to control this invasive leafminer. In this study, the genomic diversity of two tomato varieties, one tolerant and the other susceptible to T. absoluta infestation was explored, allowing us to identify chromosome regions with highly dissimilar pattern. Genes affected by potential functional variants were involved in several processes, including response to herbivory and secondary metabolism. A metabolic analysis for volatile organic compounds (VOCs) was also performed, highlighting a difference in several classes of chemicals in the two genotypes. Taken together, these findings can aid tomato breeding programs aiming to develop tolerant plants to T. absoluta.

Essential oils (EOs) and oleoresins are complex mixtures mainly made up of terpenes, synthesized by a wide variety of plants. Individual terpenes may show broad-spectrum activity against different plant pathogens, and their combination into EO and oleoresin mixtures enhances plant chemical defense. The interest in EOs has significantly increased due to the trend of using natural products as herbicides, insecticidal and antimicrobial agents. In addition, the use of plant mixtures is an emerging approach to face the problem of antimicrobial resistance in agriculture. This chapter reports guidelines about plant sample collection for the production of EOs and provides protocols to test their activity as antimicrobial agents against bacteria and fungi. It also describes a solvent-free method for the inclusion of EOs into β-cyclodextrins. This type of formulate is prepared to turn liquid EOs into easily manageable water-soluble powders, and to control the release of volatile compounds, aiming to increase EOs' applications in agriculture.

This study aimed at determining the cadmium phytoextraction potential of three Populus alba L. clones cultivated in the presence of increasing sodium chloride concentrations. Plantlets of a commercial and two autochthonous poplar clones were grown in perlite with nutrient solution enriched in CdSO4 (50 and 100 μM) and NaCl (25 and 50 mM), administered either alone or in combination. The three clones showed significant variation not only in cadmium and salt tolerance, accumulation and content, but also in the effect of the interaction between the two elements on these parameters. The toxic effect of Cd and salt excess on plants was mutually exacerbated by the presence of both. Even though the outcome of the joint treatment was always a decrease in shoot Cd or Na accumulation, the three clones showed variation in the extent of such reduction. Evaluating the total element content per plant shoot, the fast-growing commercial clone displayed the highest phytoextraction potential for Cd and Na, either alone or in mixture. Our results demonstrated for the first time that the Cd response in presence of salt can vary in the different clones.

This paper describes the antigerminant capacity of water extracts of silver fir needles created by means of hydrodynamic cavitation processes. Fir needles (2 kg fresh weight) collected in the winter were blended and crushed in ice, poured in water only (120 L) and processed in a controlled hydrodynamic cavitation device based on a fixed Venturi-shaped reactor. The A. alba water extract (AWE), comprising an oil-in-water emulsion of silver fir needles’ essential oil (100% AWE), was diluted in distilled water to 75% and 50% AWE, and all aqueous solutions were tested as antigerminant against four weeds and four horticultural species and compared to control (distilled water). This study shows the effective inhibitory effect of pure AWE on germination, which mainly contains limonene (15.99 ng/mL) and α-pinene (11.87 ng/mL). Seeds showed delayed germination and inhibition but also a reduction in radicle elongation in AWE treatments as compared to control. This combined effect was particularly evident in three weeds (C. canadensis, C. album and A. retrofllexus) while horticultural species showed mainly effects on the radicle elongation as found in L. sativa, P. crispum and S. lycospermum, which showed on average 58%, 32% and 28%, respectively, shorter radicles than in the control. P. sativum was not affected by AWE, thus raising the hypothesis that seed characteristics and nutrition reserve might play a role in the resistance to terpenes inhibitory effect.

Several factors influence the yield of rosemary essential oil obtained by steam distillation (ST) and hydro distillation (HY). This study proposes to identify and analyse them, in order to maximise essential oil yield and reducing consumptions. First, a Plackett–Burman design (PBD) was applied to test the simultaneous effect of several factors involved in the extraction process, and understand their relative influence on yield. The following factors were tested: extraction method (HY and ST), extraction time (30 min and 120 min), cooling water flow rate (1 L/m and 5 L/m), heating power (600 W and 2000 W), ratio of rosemary leaves to deionised water (solid/ liquid ratio 1:2 and 1:6). Two leaf pre-treatments were also considered: grinding and blast freezing. The PBD results identified two significant factors (extraction time and extraction method) that were subsequently validated in a full factorial experiment. Two extraction methods and four extraction times were tested. Analysis of variance results showed that maximum yield was obtained by ST with an extraction time of 120 min. Finally, chemical and physical analyses were conducted to evaluate qualitative aspects of the obtained essential oils.

Plants produce considerable amounts of volatile organic compounds (VOCs) with several biological functions, including protection against biotic agents such as viruses and their vectors. In citrus species, these metabolites can be related with their different susceptibility/tolerance toward the Tristeza virus (CTV), one of the main biotic constraints for the citrus industry. The objective of this study was to compare the VOCs pattern from the leaves of a CTV-susceptible citrus variety such as Citrus aurantium and from three CTV-tolerant varieties: Citrus volkameriana, Carrizo citrange, and Forner-Alcaide no. 5. The VOCs emitted were analyzed via the headspace SPME method, while plant metabolites sequestered in the leaves were analyzed by heptane extraction followed by GC-MS. The results indicated that the majority of the VOCs emitted and sequestered in the leaves of the varieties tolerant and susceptible to CTV are constituted mainly by volatile terpenes (VTs) that exhibit strong qualitative/quantitative differences among the profiles of the four citrus species. In detail, the VOC emission indicated different patterns between C. aurantium and C. volkameriana and from both of them in comparison with Forner-Alcaide no. 5 and Carrizo citrange that exhibited more similarities, with the last two characterized by a higher presence of sesquiterpenes. The data obtained from the analysis of the VOCs sequestered in leaf tissues of the CTV-tolerant varieties indicated a higher presence of monoterpenes such as limonene, α-pinene, and p-cymene, known to be the main components of several plant extracts showing deterrent properties toward viruses and insect vectors. As VOC evaluation is a fast and noninvasive measure of phenotypic dynamics, allowing the association of plant phenotypes in accordance to plant disease resistance and/or stress tolerance, the possible implications of such differences in terms of tolerance grade to CTV and/or its related vectors are discussed.

Le industrie farmaceutiche, agro-alimentari ed erboristiche, i laboratori galenici, la grande distribuzione ecc., esigono fitoderivati con caratteristiche e composizione chimica sempre più uniformate, nonché corredati di quelle informazioni che ne consentano un rapido indirizzo in funzione del settore finale di destinazione. Due anni di sperimentazioni condotte su oli essenziali ed idrolati di Monarda spp. per affrontare il tema della variabilità nella composizione chimica e, quindi, della standardizzazione.

Ceratocystis platani causes canker stain of plane trees, and it represents a serious disease of Platanus spp. both in the United States and Europe. Current chemical or biological controls do not effectively manage C. platani, so new preventive methods need to be developed in order to limit this pathogen spreading. In this work, we have characterized the main volatile organic compounds (VOC) emitted in vitro from pure cultures of C. platani and other common pathogenic fungal species of hosts plants growing in the same ecosystems as plane trees. We found that C. platani emitted a similar blend of VOC compared with phylogenetically similar species C. populicola. In particular, C. platani was characterized by emission of isoamyl acetate and isobutyl acetate while C. populicola by ethyl acetate and isobutyl acetate, which were not released by any of the other out-group fungal species grown on the same medium. Moreover, following a targeted approach based on the main VOC found in vitro, we have successfully validated in vivo that VOC uniquely emitted by C. platani (i.e. isobutyl acetate along with isoamyl alcohol) were released from the bark of plane trees following C. platani inoculation. Our results highlight the possibility to exploit VOC emitted specifically by C. platani as biomarkers to recognize Platanus x acerifolia plants infected by this pathogen.

Heterobasidion irregulare is a causal agent of root and butt-rot disease in conifers, and is native to North America. In 1944 it was introduced in central Italy in a Pinus pinea stand, where it shares the same niche with the native species Heterobasidion annosum. The introduction of a non-native pathogen may have significant negative effects on a naive host tree and the ecosystem in which it resides, requiring a better understanding of the system. We compared the spatio-temporal phenotypic, transcriptional and metabolic host responses to inoculation with the two Heterobasidion species in a large experiment with P. pinea seedlings. Differences in length of lesions at the inoculation site (IS), expression of host genes involved in lignin pathway and in cell rescue and defence, and analysis of terpenes at both IS and 12 cm above the IS (distal site, DS), were assessed at 3, 14 and 35 days post inoculation (dpi). Results clearly showed that both species elicit similar physiological and biochemical responses in P. pinea seedlings. The analysis of host transcripts and total terpenes showed differences between inoculation sites and between pathogen and mock inoculated plants. Both pathogen and mock inoculations induced antimicrobial peptide and phenylalanine ammonia-lyase overexpression at IS beginning at 3 dpi; while at DS all the analysed genes, except for peroxidase, were overexpressed at 14 dpi. A significantly higher accumulation of terpenoids was observed at 14 dpi at IS, and at 35 dpi at DS. The terpene blend at IS showed significant variation among treatments and sampling times, while no significant differences were ever observed in DS tissues. Based on our results, H. irregulare does not seem to have competitive advantages over the native species H. annosum in terms of pathogenicity towards P. pinea trees; this may explain why the non-native species has not widely spread over the 73 years since its putative year of introduction into central Italy.

BACKGROUND: Nowadays the preference of the consumers turned towards the consumption of functional food, and the reduction of chemical preservatives for food conservation. Moreover, the antimicrobial property and the human health promoting quality of plant secondary metabolites are well known. Due to the forecasted climate changes and increasing population, agricultural practices for saving water have become a concern. In the present study, the physiological responses of curly kale Brassica oleracea L. convar. acephala (DC) var. sabellica to drought stress and the impact of water limitation on the concentration of selected secondary metabolites were investigated in laboratory-controlled conditions. RESULTS: Results indicated that drought stress increased the content of trans-2-hexenal, phytol, as well as ? tocopherol, and decreased chlorophyll content. Moreover, drought stress increased the antioxidant capacity the expression of AOP2, a gene associated with the biosynthesis of aliphatic alkenyl glucosinolates and of three genes, TGG1, TGGE and PEN2, encoding for myrosinases, the enzymes involved in glucosinolate breakdown. CONCLUSION: The present study shows that water limitation during the growing phase might be exploited as a sustainable practice for producing curly kale with a high concentration of nutritionally important health-promoting bioactive metabolites. This article is protected by copyright. All rights reserved.

The massive use of traditional pesticides represents a worldwide problem that can no longer be postponed, due to the serious impact that these agrochemicals display on the environment. Possible strategies to lower their use include the development of natural antimicrobial agents and the improvement of their delivery efficacy. In this study, nanovectors composed of lipids extracted from the marine microalga Nannochloropsis sp. were fabricated, structurally characterized, and loaded with thymol. These nanovectors were tested as antibacterial agents against the plant pathogen Xanthomonas campestris pv. vesicatoria. The mean size of the nanoparticles was below 150 nm, with a polydispersity index ranging from 0.12 and 0.33 and a slightly negative surface charge (-4.74 to -1.19 mV). Their “backbone” was mainly made of neutral lipids, representing 76% of the lipid fraction. Concerning the loading ratio, more than 70% of thymol was uploaded into the carriers. In vitro tests showed marked bactericidal effect of the thymol-delivering nanovectors at the concentration of 250 ppm. Similar results were obtained from standard liposomes made of purified soybean phosphatidylcholine, thus encouraging further investigation on the potentialities of this algae-derived nanoformulation as novel drug delivery system.

Molti degli studi che riguardano gli o.e. hanno messo in evidenza proprietà particolarmente interessanti soprattutto nelle piante appartenenti alla vasta famiglia delle Lamiaceae, fra cui la lavanda (Lavandula spp.). Gli o.e. del genere Lavandula sono utilizzati soprattutto nell’industria alimentare (aromatizzanti), dei profumi e della cosmetica, oltre ad essere molto usati in aromaterapia. Gli oli della lavanda e dei suoi ibridi (noti come lavandini, ottenuti da Lavandula angustifolia Miller x L. latifoglia Medikus) hanno rivelato diverse proprietà, come attività antispasmodica, acaricida, antibatterica, antifungina ed antiossidante. Recentemente è stato suggerito anche un impiego come biofitofarmaco (Gonzalez-Coloma et al., 2006). Gli o.e. derivati da ibridi di lavanda appartenenti alle cvs: "Abrialis”, “Alba”, “Rinaldi Ceroni” e "Sumiens” (Figura 1), coltivati nel Giardino delle Erbe “Augusto Rinaldi Ceroni” di Casola Valsenio (Ravenna), non sono mai stati studiati per le loro proprietà antifungine. Scopo della presente ricerca è stato lo studio di nuovi o.e. derivati dalle quattro cvs di lavandino prima citate (“Abrialis”, “Alba”, “Rinaldi Ceroni” e “Sumiens”): gli oli essenziali derivati da questi lavandini sono stati caratterizzati dal punto di vista chimico e sono stati saggiati per la loro attività antifungina verso 5 specie di Candida.

Thymus spp. serve as a natural source of essential oils, fresh and dried herbs, extensively used all around the world both in medicine and in cosmetic and alimentary industries. Essential oils of T. vulgaris have been reported to be among the top 10 essential oils. Objective of this preliminary investigation was to characterize different clones of T. vulgaris in vitro shoot cultures based on their volatile terpene composition. For this purpose, in vitro shoot cultures were established by transferring the excised shoot tips of in vitro germinated seedlings on semi-solid MS medium, supplemented with 1 mg/L kinetin and 0.3 mg/L gibberellic acid and subculturing in four-week intervals to the fresh medium of the same composition. Volatile terpene composition was determined by means of capillary gas chromatography. Variations in the terpene profiles were observed between the clones that were classified into two different chemotypes. Moreover, the use of the enantiomers of α-pinene was helpful to distinguish between the different clones. These data warrants further studies in order to compare the terpene composition of in vitro and in vivo plants and to establish the utility of micropropagation techniques to propagate selected chemotypes for industrial purposes.

Rosmarinus officinalis L. is a plant of relevant commercial interest because of its volatile fraction and also its phenolic constituents which are both well known for their numerous properties. Nevertheless, an extractive method suitable to recovering both the aromatic and phenolic fractions from the same fresh foliar tissue has not yet been reported. In this work we have optimized a two-step procedure able to recover first the phenolic compounds and successively the volatile terpenes from the same foliar sample. The recovery of the whole phenolic fraction, partially degraded using a traditional extractive method, was guaranteed and we observed a significant increment in the amount of volatile terpenes compared to a traditional extraction procedure. We also highlight crucial information on the enzymatic activity of the endogenous oxidases that rapidly transform the phenolic substrates, mainly the rosmarinic acid. Our results suggest that this extractive procedure could also be used for other aromatic plants, thus providing a useful tool for more complete analyses of the main phytochemicals available in fresh foliar samples and creating the possibility of incrementing yields of volatile compounds.