Influence of the Drying Process on the Volatile Profile of Different Capsicum Species.

Chili is a globally significant spice used fresh or dried for culinary, condiment, and medicinal purposes. Growing concerns about food safety have increased the demand for high-quality products and non-invasive tools for quality control like origin tracing and safety assurance. Volatile analysis offers a rapid, comprehensive, and safe method for characterizing various food products. Thus, this study aims to assess the impact of the drying process on the aromatic composition of various Capsicum species and to identify key compounds driving the aromatic complexity of each genetic makeup. To accomplish these objectives, the aroma was examined in fruits collected from 19 different pepper accessions (Capsicum sp.) belonging to four species: one ancestral (C. chacoense) and three domesticated pepper species (C. annuum, C. baccatum and C. chinense). Fresh and dried samples were analyzed using a headspace PTR-TOF-MS platform. Our findings reveal significant changes in the composition and concentration of volatile organic compounds (VOCs) from fresh to dried Capsicum. Notably, chili peppers of the species C. chinense consistently exhibited higher emission intensity and a more complex aroma compared to other species (both fresh and dried). Overall, the data clearly demonstrate that the drying process generally leads to a reduction in the intensity and complexity of the aromatic compounds emitted. Specifically, fresh peppers showed higher volatile organic compounds content compared to dried ones, except for the two sweet peppers studied, which exhibited the opposite behavior. Our analysis underscores the variability in the effect of drying on volatile compound composition among different pepper species and even among different cultivars, highlighting key compounds that could facilitate species classification in dried powder. This research serves as a preliminary guide for promoting the utilization of various pepper species and cultivars as powder, enhancing product valorization.

Does the Harvest Type Affect Olive Health? Influence of the Harvesting System and Storage Time on the Chemical, Volatile and Sensory Qualities of Extra Virgin Olive Oils.

With the aim of investigating the effect of bruising and its development during the postharvest time, olive fruits (Frantoio and Moraiolo), manually and mechanically harvested, were stored in climatic chambers at two different temperatures (5 °C and 18 °C) for five days. Visual observations highlighted changes in the olive peel with discoloration in the damaged areas and tissue bruising. Olive fruit polyphenols, volatile organic compounds (VOCs) and other oil quality parameters (phenolic content, free acidity and peroxide index) and sensory assessment were evaluated. Analyses were carried out on fruits and experimental extra virgin oils at harvesting and after 5 days of fruit storage. The results highlight that low-temperature storage (5 °C for 5 days) may contribute to the maintenance of high olive oil quality, and the quality of olives stored at room temperature drastically decreases after 5 days of storage. Moreover, mechanical harvesting, compared to manual harvesting, does not seem to affect the final oil quality, at least at harvesting, but seems to determine differences in the long-term storage period. Finally, the samples stored at 18 °C showed a quality deterioration with the development of sensorial defects.

Metabolic Responses in Leaves of 15 Italian Olive Cultivars in Correspondence to Variable Climatic Elements.

This study aims to evaluate the metabolic changes that occurred in olive leaves as responses over time to variations in climatic elements. Rainfall, temperature, and solar radiation data were collected over 4 months (August-November) to assess the impact of different climatic trends on the metabolism of the leaves of 15 Italian olive cultivars, cultivated at the experimental farm of the University of Florence. The net photosynthetic rate (AN) and stomatal conductance (gs), measured as main indicators of primary metabolism, were mainly influenced by the "cultivar" effect compared to the "climate" effect. The lowest AN value was showed by "Bianchera", while "Ascolana" recorded the highest (8.6 and 13.6 µmol CO2 m-2s-1, respectively). On the other hand, the secondary metabolism indicators, volatile organic compound (VOC) and oleuropein (OL) content, were much more influenced by climate trends, especially rainfall. A phase of high rainfall caused a significant increase in the VOCs emission from leaves, even with different behaviors among the genotypes. The highest differences were observed between "Maiatica di Ferrandina", with the highest average values (~85,000 npcs), and "Frantoio", which showed the lowest (~22,700 npcs). The OL content underwent considerable fluctuations in relation to the rainfall but also appeared to be controlled by the genotype. "Coratina" always showed the highest OL concentration (reaching the maximum ~98 mg g-1), indicating the great potential of this cultivar for the industrial recovery of OL.

Can microplastics threaten plant productivity and fruit quality? Insights from Micro-Tom and Micro-PET/PVC.

Solanum lycopersicum L., a crop grown worldwide with a high nutritional value for the human diet, was used to test the impact of microplastics on plant growth, productivity, and fruit quality. Two of the most represented microplastics in soils, polyethylene terephthalate (PET) and polyvinyl chloride (PVC), were tested. Plants were grown in pots with an environmentally realistic concentration of microplastics and, during the whole crop life cycle, photosynthetic parameters, number of flowers and fruits were monitored. At the end of the cultivation, plant biometry and ionome were evaluated, along with fruit production and quality. Both pollutants had negligible effects on shoot traits, with only PVC causing a significant reduction in shoot fresh weight. Despite an apparent low or no toxicity during the vegetative stage, both microplastics decreased the number of fruits and, in the case of PVC, also their fresh weights. The plastic polymer-induced decline in fruit production was coupled with wide variations in fruit ionome, with marked increases in Ni and Cd. By contrast there was a decline in the nutritionally valuable lycopene, total soluble solids, and total phenols. Altogether, our results reveal that microplastics can not only limit crop productivity but also negatively impact fruit quality and enhance the concentration of food safety hazards, thus raising concerns for their potential health risks for humans.

Intercropping Salt-Sensitive Lactuca sativa L. and Salt-Tolerant Salsola soda L. in a Saline Hydroponic Medium: An Agronomic and Physiological Assessment.

Competition for freshwater is increasing, with a growing population and the effects of climate change limiting its availability. In this experiment, Lactuca sativa plants were grown hydroponically with or without a 15% share of seawater (12 dS m-1) alone or intercropped with Salsola soda to demonstrate if L. sativa benefits from sodium removal by its halophyte companion. Contrary to the hypothesis, saline-grown L. sativa plants demonstrated reduced growth compared to the control plants regardless of the presence or absence of S. soda. Both limitations in CO2 supply and photosystem efficiency may have decreased CO2 assimilation rates and growth in L. sativa plants grown in the seawater-amended solutions. Surprisingly, leaf pigment concentrations increased in salt-treated L. sativa plants, and most notably among those intercropped with S. soda, suggesting that intercropping may have led to shade-induced increases in chlorophyll pigments. Furthermore, increased levels of proline indicate that salt-treated L. sativa plants were experiencing stress. In contrast, S. soda produced greater biomass in saline conditions than in control conditions. The mineral element, carbohydrate, protein, polyphenol and nitrate profiles of both species differed in their response to salinity. In particular, salt-sensitive L. sativa plants had greater accumulations of Fe, Ca, P, total phenolic compounds and nitrates under saline conditions than salt-tolerant S. soda. The obtained results suggest that intercropping salt-sensitive L. sativa with S. soda in a hydroponic system did not ameliorate the growing conditions of the salt-sensitive species as was hypothesized and may have exacerbated the abiotic stress by increasing competition for limited resources such as light. In contrast, the saline medium induced an improvement in the nutritional profile of S. soda. These results demonstrate an upper limit of the seawater share and planting density that can be used in saline agriculture when intercropping S. soda plants with other salt-sensitive crops.

Salt stress in olive tree shapes resident endophytic microbiota.

Olea europaea L. is a glycophyte representing one of the most important plants in the Mediterranean area, both from an economic and agricultural point of view. Its adaptability to different environmental conditions enables its cultivation in numerous agricultural scenarios, even on marginal areas, characterized by soils unsuitable for other crops. Salt stress represents one current major threats to crop production, including olive tree. In order to overcome this constraint, several cultivars have been evaluated over the years using biochemical and physiological methods to select the most suitable ones for cultivation in harsh environments. Thus the development of novel methodologies have provided useful tools for evaluating the adaptive capacity of cultivars, among which the evaluation of the plant-microbiota ratio, which is important for the maintenance of plant homeostasis. In the present study, four olive tree cultivars (two traditional and two for intensive cultivation) were subjected to saline stress using two concentrations of salt, 100 mM and 200 mM. The effects of stress on diverse cultivars were assessed by using biochemical analyses (i.e., proline, carotenoid and chlorophyll content), showing a cultivar-dependent response. Additionally, the olive tree response to stress was correlated with the leaf endophytic bacterial community. Results of the metabarcoding analyses showed a significant shift in the resident microbiome for plants subjected to moderate salt stress, which did not occur under extreme salt-stress conditions. In the whole, these results showed that the integration of stress markers and endophytic community represents a suitable approach to evaluate the adaptation of cultivars to environmental stresses.

Bacterial Communities in the Fruiting Bodies and Background Soils of the White Truffle Tuber magnatum.

Tuber magnatum Picco is a greatly appreciated truffle species mainly distributed in Italy. Its price and characteristics mostly depend on its geographical origin. Truffles represent a fundamental step of the life cycle of Tuber species promoting spore dissemination. They consist of two main parts, gleba, the inner part, and peridium, which is in direct contact with ground soil. Within the truffle and around in the growing soil, both the occurrence and abundance of different microbial species seem to play an essential role in truffle production. The development of the next-generation sequencing (NGS) based technology has greatly improved to deepen the role of the composition of microbial communities, thus improving the knowledge of the existing relationships between microbial taxa in a specific condition. Here, we applied a metabarcoding approach to assess the differences in T. magnatum samples collected from three areas in Tuscany (Italy). Peridium and gleba were analyzed separately with the aim to distinguish them based on their microbial composition. Also, soil samples were collected and analyzed to compare productive and unproductive truffle grounds to confirm the presence of specific patterns linked to truffle production. Results indicate that differences occurred between truffle compartments (gleba and peridium) as well as between analyzed soils (productive and unproductive), with distinctive taxa associated. Furthermore, findings also demonstrated specific characteristics associated with truffle collection areas, thus indicating a degree of microbial selection related to different environments.

Stalk cell polar ion transport provide for bladder-based salinity tolerance in Chenopodium quinoa.

Chenopodium quinoa uses epidermal bladder cells (EBCs) to sequester excess salt. Each EBC complex consists of a leaf epidermal cell, a stalk cell, and the bladder. Under salt stress, sodium (Na+ ), chloride (Cl- ), potassium (K+ ) and various metabolites are shuttled from the leaf lamina to the bladders. Stalk cells operate as both a selectivity filter and a flux controller. In line with the nature of a transfer cell, advanced transmission electron tomography, electrophysiology, and fluorescent tracer flux studies revealed the stalk cell's polar organization and bladder-directed solute flow. RNA sequencing and cluster analysis revealed the gene expression profiles of the stalk cells. Among the stalk cell enriched genes, ion channels and carriers as well as sugar transporters were most pronounced. Based on their electrophysiological fingerprint and thermodynamic considerations, a model for stalk cell transcellular transport was derived.

The Physiological Response of Different Brook Willow (Salix acmophylla Boiss.) Ecotypes to Salinity.

Few phytoremediation studies have been conducted under semi-arid conditions where plants are subjected to drought and/or salinity stress. Although the genus Salix is frequently used in phytoremediation, information regarding its tolerance of drought and salinity is limited. In the present study, Salix acmophylla Boiss. cuttings from three sites (Adom, Darom and Mea She'arim) were tested for tolerance to salinity stress by growing them hydroponically under either control or increasing NaCl concentrations corresponding to electrical conductivities of 3 and 6 dS m-1 in a 42-day greenhouse trial. Gas exchange parameters, chlorophyll fluorescence and concentration, and water-use efficiency were measured weekly and biomass was collected at the end of the trial. Root, leaf and stem productivity was significantly reduced in the Adom ecotype, suggesting that Darom and Mea She'arim are the more salt-tolerant of the three ecotypes. Net assimilation and stomatal conductance rates in salt-treated Adom were significantly reduced by the last week of the trial, coinciding with reduced intrinsic water use efficiency and chlorophyll a content and greater stomatal aperture. In contrast, early reductions in stomatal conductance and stomatal aperture in Darom and Mea She'arim stabilized, together with pigment concentrations, especially carotenoids. These results suggest that Darom and Mea She'arim are more tolerant to salt than Adom, and provide further phenotypic support to the recently published data demonstrating their genetic similarities and their usefulness in phytoremediation under saline conditions.

Early signalling processes in roots play a crucial role in the differential salt tolerance in contrasting Chenopodium quinoa accessions.

Significant variation in epidermal bladder cell (EBC) density and salt tolerance (ST) exists amongst quinoa accessions, suggesting that salt sequestration in EBCs is not the only mechanism conferring ST in this halophyte. In order to reveal other traits that may operate in tandem with salt sequestration in EBCs and whether these additional tolerance mechanisms acted mainly at the root or shoot level, two quinoa (Chenopodium quinoa) accessions with contrasting ST and EBC densities (Q30, low ST with high EBC density versus Q68, with high ST and low EBC density) were studied. The results indicate that responses in roots, rather than in shoots, contributed to the greater ST in the accession with low EBC density. In particular, the tolerant accession had improved root plasma membrane integrity and K+ retention in the mature root zone in response to salt. Furthermore, superior ST in the tolerant Q68 was associated with faster and root-specific H2O2 accumulation and reactive oxygen species-induced K+ and Ca2+ fluxes in the root apex within 30 min after NaCl application. This was found to be associated with the constitutive up-regulation of the membrane-localized receptor kinases regulatory protein FERONIA in the tolerant accession. Taken together, this study shows that differential root signalling events upon salt exposure are essential for the halophytic quinoa; the failure to do this limits quinoa adaptation to salinity, independently of salt sequestration in EBCs.

Modelling botanical biofiltration of indoor air streams contaminated by volatile organic compounds.

Botanical filtration is a biological-based treatment method suitable for removing hazardous volatile organic compounds (VOCs) from air streams, based on forcing an air flow through a porous substrate and foliage of a living botanical compartment. The pathways and removal mechanisms during VOC bioremediation have been largely investigated; however, their mathematical representation is well established only for the non-botanical components of the system. In this study, we evaluated the applicability of such a modelling scheme to systems which include a botanical compartment. We implemented a one-dimensional numerical model and performed a global sensitivity analysis to measure the input parameters influence on the transient and steady biofilter responses. We found that the most sensitive parameters on the transient-state behaviour were the mass transfer coefficient between gas and solid surfaces, and the fraction of solid surfaces covered by the biofilm; the steady-state response was primarily influenced by the biofilm specific surface area and the fraction of surfaces covered by the biofilm. We calibrated the identified set of parameters and successfully validated the model against data from a pilot-scale installation. The results showed that the application of the model to systems with a botanical compartment is feasible, although under a strict set of assumptions.

Our sisters the plants? notes from phylogenetics and botany on plant kinship blindness.

Before the upheaval brought about by phylogenetic classification, classical taxonomy separated living beings into two distinct kingdoms, animals and plants. Rooted in 'naturalist' cosmology, Western science has built its theoretical apparatus on this dichotomy mostly based on ancient Aristotelian ideas. Nowadays, despite the adoption of the Darwinian paradigm that unifies living organisms as a kinship, the concept of the "scale of beings" continues to structure our analysis and understanding of living species. Our aim is to combine developments in phylogeny, recent advances in biology, and renewed interest in plant agency to craft an interdisciplinary stance on the living realm. The lines at the origin of plant or animal have a common evolutionary history dating back to about 3.9 Ga, separating only 1.6 Ga ago. From a phylogenetic perspective of living species history, plants and animals belong to sister groups. With recent data related to the field of Plant Neurobiology, our aim is to discuss some socio-cultural obstacles, mainly in Western naturalist epistemology, that have prevented the integration of living organisms as relatives, while suggesting a few avenues inspired by practices principally from other ontologies that could help overcome these obstacles and build bridges between different ways of connecting to life.

Relationship between Leachate Pollution Index and growth response of two willow and poplar hybrids: Implications for phyto-treatment applications.

Phytoremediation is a potentially suitable technique for the reclamation of toxic landfill leachate (LL) by decreasing its volume through water uptake and improving its composition by uptake, accumulation and amelioration of pollutants. We investigated the use of two parameters, the LL concentration and the Leachate Pollution Index (LPI), a method used to determine the phytotoxicity potential of a leachate source based on a weighted sum of its components, to set the best LL dilution to apply when poplar clone 'Orion' and willow clone 'Levante' are selected for phytoremediation. Cuttings were watered with five LL concentrations ranging from 0 to 100%. The poplar clone showed significantly higher values than the willow clone for lowest effective concentration index (LOEC) for leaf (i.e. 11.3% vs 10.5%; p = 0.0284) and total biomass (i.e. 10.9% vs 10.6%; p = 0.0402) and for lowest effective LPI for leaf (i.e. 12.3 vs 12.1; p = 0.0359) and total biomass (i.e. 12.8 versus 12.2; p = 0.0365), respectively, with effectiveness demonstrating the LOEC or LPI value at which the parameter is negatively affected. Photosynthetic rates were higher in poplar than willow in both control and the lowest LL dilution, but rapidly declined in both at higher LL dilutions. Although a direct translation of data from bench trials to field conditions should be investigated, we concluded that in the establishment phase, the poplar hybrid is more tolerant than the willow hybrid to LL. We also provide evidence for LPI as a potential predictor for setting LL irrigation levels in the initial phase of a phyto-treatment approach.

Are Peach Cultivars Used in Conventional Long Food Supply Chains Suitable for the High-Quality Short Markets?

Peaches are climacteric and highly perishable fruits, with a short shelf life, and are prone to rapid deterioration after harvest. In this study, the chemical proprieties, aroma profile and a sensory evaluation were conducted to: (1) characterize and compare fruits of 13 different peach and nectarine cultivars, harvested at physiological maturation; and (2) assess the suitability of these cultivars, that are successfully used in long food supply chains (LFSCs), for their use in short food supply chains (SFSCs). Through statistical analysis clear differences were found among the studied cultivars, and in particular between cultivars suited to SFSCs compared to those suited for LFSCs. Results indicate that, despite all cultivars being planted in the same orchards and with the same pre-harvest management and practices, their post-harvest performances were mainly influenced by the cultivar genetic makeup. Therefore, cultivars conventionally used in SFSCs, such as "Guglielmina" and "Regina di Londa", had the best aroma, sweetness and juiciness compared to LSCPs ones. In contrast, the LSCPs varieties showed interesting values for firmness and crunchiness.

Barbara G. Pickard - Queen of Plant Electrophysiology.

Barbara Gillespie Pickard (1936-2019) studied plant electrophysiology and mechanosensory biology for more than 50 y. Her first papers on the roles of auxin in plant tropisms were coauthored with Kenneth V. Thimann. Later, she studied plant electrophysiology. She made it clear that plant action potentials are not a peculiar feature of so-called sensitive plants, but that all plants exhibit these fast electric signals. Barbara Gillespie Pickard proposed a neuronal model for the spreading of electric signals induced by mechanical stimuli across plant tissues. In later years, she studied the stretch-activated plasma membrane channels of plants and formulated the plasma-membrane control center model. Barbara Pickard summarized all her findings in a new model of phyllotaxis involving waves of auxin fluxes and mechano-sensory signaling.

Early responses to salt stress in quinoa genotypes with opposite behavior.

Soil salinity is among the major abiotic stresses that plants must cope with, mainly in arid and semiarid regions. The tolerance to high salinity is an important agronomic trait to sustain food production. Quinoa is a halophytic annual pseudo-cereal species with high nutritional value that can secrete salt out of young leaves in external non-glandular cells called epidermal bladder cells (EBC). Previous work showed high salt tolerance, but low EBC density was associated with an improved response in the early phases of salinity stress, mediated by tissue-tolerance traits mainly in roots. We compared the transcript profiling of two quinoa genotypes with contrasting salt tolerance patterning to identify the candidate genes involved in the differentially early response among genotypes. The transcriptome profiling, supported by in vitro physiological analyses, provided insights into the early-stage molecular mechanisms, both at the shoot and root level, based on the sensitive/tolerance traits. Results showed the presence of numerous differentially expressed genes among genotypes, tissues, and treatments, with genes involved in hormonal and stress response upregulated mainly in the sensitive genotype, suggesting that tolerance may be correlated to restricted changes in gene expression, at least after a short salt stress. These data, showing constitutive differences between the two genotypes, represent a solid basis for further studies to characterize the salt tolerance traits. Additionally, new information provided by this work might be useful for the development of plant breeding or genome engineering programs in quinoa.

Biphasic activation of survival and death pathways in Arabidopsis thaliana cultured cells by sorbitol-induced hyperosmotic stress.

Hyperosmotic stresses represent some of the most serious abiotic factors that adversely affect plants growth, development and fitness. Despite their central role, the early cellular events that lead to plant adaptive responses remain largely unknown. In this study, using Arabidopsis thaliana cultured cells we analyzed early cellular responses to sorbitol-induced hyperosmotic stress. We observed biphasic and dual responses of A. thaliana cultured cells to sorbitol-induced hyperosmotic stress. A first set of events, namely singlet oxygen (1O2) production and cell hyperpolarization due to a decrease in anion channel activity could participate to signaling and osmotic adjustment allowing cell adaptation and survival. A second set of events, namely superoxide anion (O2-) production by RBOHD-NADPH-oxidases and SLAC1 anion channel activation could participate in programmed cell death (PCD) of a part of the cell population. This set of events raises the question of how a survival pathway and a death pathway could be induced by the same hyperosmotic condition and what could be the meaning of the induction of two different behaviors in response to hyperosmotic stress.

Individuality, self and sociality of vascular plants.

Vascular plants are integrated into coherent bodies via plant-specific synaptic adhesion domains, action potentials (APs) and other means of long-distance signalling running throughout the plant bodies. Plant-specific synapses and APs are proposed to allow plants to generate their self identities having unique ways of sensing and acting as agents with their own goals guiding their future activities. Plants move their organs with a purpose and with obvious awareness of their surroundings and require APs to perform and control these movements. Self-identities allow vascular plants to act as individuals enjoying sociality via their self/non-self-recognition and kin recognition. Flowering plants emerge as cognitive and intelligent organisms when the major strategy is to attract and control their animal pollinators as well as seed dispersers by providing them with food enriched with nutritive and manipulative/addictive compounds. Their goal in interactions with animals is manipulation for reproduction, dispersal and defence. This article is part of the theme issue 'Basal cognition: multicellularity, neurons and the cognitive lens'.

Quali-quantitative monitoring of chemocatalytic cellulose conversion into lactic acid by FT-NIR spectroscopy.

Chemocatalytic conversion of cellulose into lactic acid is a valuable alternative to simple sugar fermentation. Nevertheless, the procedures still need optimization to be translated to the industrial scale. Such translation would benefit by on-line monitoring of reaction parameters by fast, inexpensive, direct spectroscopic techniques. In this work, we propose the application of FT-NIR spectroscopy as a suitable analytical tool for monitoring the chemocatalytic conversion of cellulose into lactic acid. Comparison between different FT-NIR spectra at different reaction temperatures and times was exploited to qualitatively indicate the feasibility of the reaction. Besides, an FT-NIR prediction model was proposed for rapidly estimating the molar distribution of cellulose catalytic degradation components in the reaction mixtures. The calibration model was based on reference samples analysed by HPLC. The model was validated by an external validation set. Relevant statistical values of Ratio Performance to Deviations (RPD) referred to both calibration and external validation were obtained, thus demonstrating the potential of such analytical technique in process monitoring.

Semi-synthesis as a tool for broadening the health applications of bioactive olive secoiridoids: a critical review.

Covering: 2005 up to 2020Olive bioactive secoiridoids are recognized as natural antioxidants with multiple beneficial effects on human health. Nevertheless, the study of their biological activity has also disclosed some critical aspects associated with their application. Firstly, only a few of them can be extracted in large amounts from their natural matrix, namely olive leaves, drupes, oil and olive mill wastewater. Secondly, their application as preventive agents and drugs is limited by their low membrane permeability. Thirdly, the study of their biological fate after administration is complicated by the absence of pure analytical standards. Accordingly, efficient synthetic methods to obtain natural and non-natural bioactive phenol derivatives have been developed. Among them, semi-synthetic protocols represent efficient and economical alternatives to total synthesis, combining efficient extraction protocols with efficient catalytic conversions to achieve reasonable amounts of active molecules. The aim of this review is to summarize the semi-synthetic protocols published in the last fifteen years, covering 2005 up to 2020, which can produce natural olive bioactive phenols scarcely available by extractive procedures, and new biophenol derivatives with enhanced biological activity. Moreover, the semi-synthetic protocols to produce olive bioactive phenol derivatives as analytical standards are also discussed. A critical analysis of the advantages offered by semi-synthesis compared to classical extraction methods or total synthesis protocols is also performed.