Exogenous melatonin application helps late-sown durum wheat to cope with waterlogging under Mediterranean environmental conditions.

In Mediterranean countries, late-sown durum wheat (Triticum turgidum L. subsp. durum) may face waterlogging (WL) at early stages. As mitigation of waterlogging by melatonin (MT) has been poorly explored, we analyzed the effects of exogenous MT foliar application to WL-stressed durum wheat on its ecophysiological performance, growth and biomass production. Late-sown plants of a relatively tolerant cultivar (i.e., Emilio-Lepido) were subjected to two WL durations (i.e., 14 and 35 days of WL; DOW) at tillering, with or without exogenous MT application (i.e., 0 and 100 µM). Prolonged WL reduced shoot biomass (-43%), but the application of MT mitigated this detrimental effect. Waterlogging impaired photosynthesis, reducing leaf CO2 assimilation and chlorophyll content (-61 and - 57%, at 14 and 35 DOW). In control, MT increased the photosynthetic pigments (+48%), whereas it exacerbated the decrease in photosynthesis under both WL conditions (-72%, on average). Conversely, MT reduced WL-induced oxidative damage in both shoots and roots (-25% hydrogen peroxide production), facilitating osmotic adjustments and mitigating oxidative stress. The accumulation of osmotic regulators in MT + WL plants (+140 and + 42%, in shoots and roots at 35 DOW; respectively) and mineral solutes (+140 and + 104%, on average, in shoots and roots at 14 DOW) likely mitigated WL stress, limiting the impact of oxidative stress and promoting biomass accumulation. Our results highlight the potential of MT as a bioactive compound in mitigating the adverse effects of WL on late-sown durum wheat and the importance of the complex interactions between physiological responses and environmental stressors.

Ozone Treatment as an Approach to Induce Specialized Compounds in Melissa officinalis Plants.

Plants are constantly subjected to environmental changes that deeply affect their metabolism, leading to the inhibition or synthesis of "specialized" compounds, small organic molecules that play a fundamental role in adaptative responses. In this work, Melissa officinalis L. (an aromatic plant broadly cultivated due to the large amounts of secondary metabolites) plants were exposed to realistic ozone (O3) dosages (80 ppb, 5 h day-1) for 35 consecutive days with the aim to evaluate its potential use as elicitor of specialized metabolite production. Ozone induced stomatal dysfunction throughout the whole experiment, associated with a low photosynthetic performance, a decrease in the potential energy conversion activity of PSII, and an alteration in the total chlorophyll content (-35, -36, -10, and -17% as average compared to the controls, respectively). The production of hydrogen peroxide at 7 days from the beginning of exposure (+47%) resulted in lipid peroxidation and visible injuries. This result suggests metabolic disturbance within the cell and a concomitant alteration in cell homeostasis, probably due to a limited activation of antioxidative mechanisms. Moderate accumulated doses of O3 triggered the accumulation of hydroxycinnamic acids and the up-regulation of the genes encoding enzymes involved in rosmarinic acid, phenylpropanoid, and flavonoid biosynthesis. While high accumulated doses of O3 significantly enhanced the content of hydroxybenzoic acid and flavanone glycosides. Our study shows that the application of O3 at the investigated concentration for a limited period (such as two/three weeks) may become a useful tool to stimulate bioactive compounds production in M. officinalis.

Untangling the role of leaf age specific osmoprotectant and antioxidant responses of two poplar clones under increasing ozone concentrations.

Plants possess different degrees of tolerance to abiotic stress, which can mitigate the detrimental effect of environmental inputs affecting carbon balance. Less is known about the functions of osmoprotectants in scavenging of reactive oxygen species (ROS), generated at different sites depending on leaf age. This study aimed to clarify the osmotic adjustments adopted by old and young leaves of Oxford and I-214 poplar clones [differing in ozone (O3) sensitivity] to cope with three levels of O3 [ambient (AA), and two elevated O3 levels]. In both clones, the impact of intermediate O3 concentrations (1.5 × AA) on ROS production appeared to be leaf age-specific, given the accumulation of hydrogen peroxide (H2O2) observed only in old leaves of the Oxford plants and in young leaves of the I-214 ones (2- fold higher than AA and +79%, respectively). The induction of an oxidative burst was associated with membrane injury, indicating an inadequate response of the antioxidative systems [decrease of lutein and ß-carotene (-37 and -85% in the old leaves of the Oxford plants), accumulation of proline and tocopherols (+60 and +12% in the young leaves of the I-214 ones)]. Intermediate O3 concentrations reacted with unsaturated lipids of the plasma membrane in old and young leaves of the Oxford plants, leading to an increase of malondialdehyde by-products (more than 2- fold higher than AA), while no effect was recorded for I-214. The impact of the highest O3 concentrations (2.0 × AA) on ROS production did not appear clone-specific, which may react with cell wall components by leading to oxidative pressure. Outcomes demonstrated the ability of young leaves of I-214 plants in contain O3 phytotoxic effects.

Biocontrol Agents of Fusarium Head Blight in Wheat: A Meta-Analytic Approach to Elucidate Their Strengths and Weaknesses.

The use of biocontrol agents (BCAs) coping with fungal pathogens causing Fusarium head blight (FHB) is a compelling strategy for disease management, but a better elucidation of their effectiveness is crucial. Meta-analysis is the analysis of the results of multiple studies, which is typically performed to synthesize evidence from many possible sources in a formal probabilistic manner. This meta-analytic study, including 30 pathometric, biometric, physiochemical, genetic, and mycotoxin response variables reported in 56 studies, evidences the BCA effects on FHB in wheat. The effectiveness of BCAs of FHB in wheat in terms of pathogen abundance and disease reductions, biomass and yield conservation, and mycotoxin prevention/control was confirmed. BCAs showed higher efficacy (i) in studies published more recently; (ii) under controlled conditions; (iii) in high susceptible wheat cultivars; (iv) when Fusarium inoculation and BCA treatment did not occur directly on the plant (i.e., at the seed and kernel levels) in terms of disease development and mycotoxin control, and vice versa in terms of biomass conservation; (v) if Fusarium inoculation and BCA treatment occurred by spraying spikes in terms of yield; (vi) at 15 to 21 days post Fusarium inoculation or BCA treatment; and (vii) if they were filamentous fungi. However, BCAs overall were less efficacious than conventional agrochemicals, especially in terms of pathogen abundance and FHB reductions, as well as of mycotoxin prevention/control, although inconsistencies were reported among the investigated moderator variables. This study also highlights the complexity of reaching a good balance among BCA effects, and the need for further research.

Exogenous application of melatonin protects bean and tobacco plants against ozone damage by improving antioxidant enzyme activities, enhancing photosynthetic performance, and preventing membrane damage.

Ozone (O3) pollution is harmful to plants and ecosystems. Several chemicals have been evaluated to protect plants against O3 deleterious effects. However, they are not adequately efficient and/or the environmental safety of their application is questioned. Hence, new chemicals that provide sufficient protection while being safer for environmental application are needed. This study investigates the response of two O3-sensitive plant species (Phaseolus vulgaris L. cv. Pinto and Nicotiana tabacum L. cv. Bel-W3) leaf-sprayed with deionized water (W, control), ethylenediurea (EDU, 1 mM) or melatonin at lower (1 mM) or higher (3 mM) concentrations (Mel_L and Mel_H, respectively), and then exposed to a square wave of 200 ppb O3, lasting 1 day (5 h day-1) for bean and 2 days (8 h day-1) for tobacco. In both species, the photosynthetic activity of O3-exposed plants was about halved. O3-induced membrane damage was also confirmed by increased malondialdehyde (MDA) byproducts compared to control (W). In EDU- and Mel-treated bean plants, the photosynthetic performance was not influenced by O3, leading to reduction of the incidence and severity of O3 visible injury. In bean plants, Mel_L mitigated the detrimental effect of O3 by boosting antioxidant enzyme activities or osmoprotectants (e.g. abscisic acid, proline, and glutathione transferase). In Mel_L-sprayed tobacco plants, O3 negatively influenced the photosynthetic activity. Conversely, Mel_H ameliorated the O3-induced oxidative stress by preserving the photosynthetic performance, preventing membrane damage, and reducing the visible injuries extent. Although EDU performed better, melatonin protected plants against O3 phytotoxicity, suggesting its potential application as a bio-safer and eco-friendlier phytoprotectant against O3. It is worth noting that the content of melatonin in EDU-treated plants remained unchanged, indicating that the protectant mode of action of EDU is not Mel-related.

Isolation and characterization of Fusarium spp. From unhatched eggs of Caretta caretta in Tuscany (Italy).

Sea Turtle Egg Fusariosis (STEF) is a worldwide emergent fungal disease affecting eggs and causing embryos mortality in turtle's nests such as those of Caretta caretta. It is caused by a complex of species belonging to Fusarium genus, particularly those included in the Fusarium Solani Species Complex (FSSC). During the samplings carried out in summer 2020 along the Tuscany coastlines (Italy), C. caretta eggs showed clinical signs resembling those caused by STEF. A total of 32 fungal isolates were obtained from lesioned eggs whose molecular characterization allowing identifying as belonging to FSSC / Neocosmospora spp., Fusarium oxysporum Species Complex (FOSC) / F. oxysporum and Fusarium nodosum, i.e., fungal genera and speciesincluding also well-known plant pathogens. Isolates inoculated on several plant hosts did not result in any pathogenic activity but F. nodosum causing, on wheat spikes, disease symptoms.This is the first time F. nodosum has been isolated from portions of eggs showing evident signs of fungal infection. This work represents the first report of Fusarium spp. isolated from C. caretta eggs showing lesions resembling those caused by STEF on Tuscan coast thus posing a significant concern to loggerhead sea turtle conservation also in this region.

The magpie and the grapes: increasing ozone exposure impacts fruit consumption by a common corvid in a suburban environment.

BACKGROUND: The Eurasian magpie Pica pica is a resident bird species able to colonize farmlands and anthropized environments. This corvid shows a wide trophic spectrum by including fruits, invertebrates, small vertebrates and carcasses in its diet. A camera-trap experiment was carried out to test the effect of different ozone (O3 ) concentrations on potted Vitis vinifera plants, which resulted in different grape consumption rates by suburban birds. The test was performed at an Ozone-Free Air Controlled Exposure (FACE) facility, consisting of nine plots with three ozone (O3 ) levels: AA (ambient O3 concentration); and two elevated O3 levels, 1.5× AA (ambient air with a 50% increase in O3 concentration) and 2.0× AA (ambient air with a 100% increase in O3 concentration). Camera-traps were located in front of each treatment area and kept active for 24 h day-1 and for 5 days at a time over a period of 3 months to monitor grape consumption by birds. RESULTS: We collected a total of 38 videos. Eurasian magpies were the only grape consumers, with a total of 6.7 ± 3.3 passages per hour (mean ± SD) and no differences across the different O3 treatments. Grapes in the AA treatment were consumed significantly more quickly than those in the 1.5× AA treatment, which in turn, were consumed faster than those in the 2.0× AA treatment. At 3 days from the start of treatment, 94%, 53% and 22% berries from the AA, 1.5× AA and 2.0× AA treatments had been eaten, respectively. When the O3 was turned off, berries were consumed at the same rate among treatments. CONCLUSION: Increasing O3 concentrations limited grape consumption by magpies probably because O3 acted as a deterrent for magpies, although the lower sugar content recorded in the 2.0× AA berries did not affect the consumption when O3 was turned off. Our results provided valuable insights to mitigate human-wildlife conflicts in suburban environments. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Ozone-Induced Biochemical and Molecular Changes in Vitis vinifera Leaves and Responses to Botrytis cinerea Infections.

To investigate how plants cope with multi-stress conditions, we analyzed the biochemical and molecular changes of Vitis vinifera leaves subjected to single or sequential double stresses (infection by Botrytis cinerea (Bc) and ozone (O3, 100 ppb for 3 h) treatment). In Bc+/O3- leaves, the hydrogen peroxide (H2O2) induction (observed at 12 and 24 h from the end of treatment (FET)) triggered a production of ethylene (Et; +35% compared with Bc-/O3- leaves), which was preceded by an increase of salicylic acid (SA; +45%). This result confirms a crosstalk between SA- and Et-related signaling pathways in lesion spread. The ozone induced an early synthesis of Et followed by jasmonic acid (JA) and SA production (about 2-fold higher), where Et and SA signaling triggered reactive oxygen species production by establishing a feedback loop, and JA attenuated this cycle by reducing Et biosynthesis. In Bc+ + O3+ leaves, Et peaked at 6 and 12 h FET, before SA confirmed a crosstalk between Et- and SA-related signaling pathways in lesion propagation. In O3+ + Bc+ leaves, the H2O2 induction triggered an accumulation of JA and Et, demonstrating a synergistic action in the regulation of defence reactions. The divergence in these profiles suggests a rather complex network of events in the transcriptional regulation of genes involved in the systemic acquired resistance.

Mushroom-Based Supplements in Italy: Let's Open Pandora's Box.

Mushrooms and derivates are well known to the scientific community for having different health benefits and exhibit a wide range of pharmacological activities, including lipid-lowering, antihypertensive, antidiabetic, antimicrobic, antiallergic, anti-inflammatory, anticancer, immunomodulating, neuroprotective and osteoprotective actions. In Europe, medical mushrooms are mainly marketed in the form of food supplements as single components or combined with other nutraceuticals. In this context, the first peculiarity that distinguishes it is the safety established through the "history of consumption" that characterizes that mushroom. However, the cultivation of medicinal mushrooms on a large scale is performed mainly in China, where most of the production facilities do not have internationally recognized good manufacturing practices, despite that many European companies that sell myotherapies are supplied by Chinese manufacturers. This is particularly evident in Italy, where an arsenal of mushroom products is marketed in the form of powders and extracts not always of ascertained origin and sometimes of doubtful taxonomic identification, and thus not meeting the quality criteria required. The growing interest in mycotherapy involves a strong commitment from the scientific community to propose supplements of safe origin and genetic purity as well as to promote clinical trials to evaluate its real effects on humans. The purpose of this research is to analyze different mushroom-based dietary supplements used in medicine as monotherapy on the Italian market and to evaluate their composition and quality. The molecular identification of the sequences with those deposited in GenBank allowed for identifying 6 out of 19 samples, matching with those deposited belonging to the species indicated in the label, i.e., Lentinula edodes (samples 1, 4, 12 and 18) and Ganoderma lucidum (samples 5 and 10). Samples containing Ganoderma, labeled in the commercial product as G. lucidum, showed sequences that showed homology of 100% and 99% with G. resinaceum and G. sichuanense. An additional investigation was carried out in order to determine the active fungal ingredients, such as ergosterol, aflatoxins, heavy metals, nicotine and total glucan. The results obtained and shown in the manuscript highlight how the data were not only in line with what is expected with respect to what is indicated in the labels.

Sustainable Strategies to Counteract Mycotoxins Contamination and Cowpea Weevil in Chickpea Seeds during Post-Harvest.

Mycotoxins contamination and pest infestation of foods and feeds represent a pivotal threat for food safety and security worldwide, with crucial implications for human and animal health. Controlled atmosphere could be a sustainable strategy to reduce mycotoxins content and counteract the vitality of deleterious organisms in foodstuff. Ozone treatment (O3, 500 ppb for 30, 60 or 90 min) and high nitrogen concentration (N2, 99% for 21 consecutive days) were tested in the post-harvest management of four batches of Cicer arietinum grains to control the presence of mycotoxigenic fungi and their secondary metabolites, as well as pest (i.e., Callosobruchus maculatus) infestation. At the end of the treatment, O3 significantly decreased the incidence of Penicillium spp. (by an average of -50%, independently to the time of exposure) and reduced the patulin and aflatoxins content after 30 min (-85 and -100%, respectively). High N2 concentrations remarkably reduced mycotoxins contamination (by an average of -94%) and induced pest mortality (at 100% after 5 days of exposure). These results confirm the promising potential of O3 and N2 in post-harvest conservation strategies, leading to further investigations to evaluate the effects on the qualitative characteristics of grains.

Trichoderma-Induced Resistance to Botrytis cinerea in Solanum Species: A Meta-Analysis.

With the idea of summarizing the outcomes of studies focusing on the resistance induced by Trichoderma spp. against Botrytis cinerea in tomato, the present paper shows, for the first time, results of a meta-analysis performed on studies published from 2010 to 2021 concerning the cross-talk occurring in the tomato-Trichoderma-B. cinerea system. Starting from an initial set of 40 papers, the analysis was performed on 15 works and included nine parameters, as a result of a stringent selection mainly based on the availability of more than one article including the same indicator. The resulting work not only emphasizes the beneficial effects of Trichoderma in the control of grey mold in tomato leaves (reduction in disease intensity, severity and incidence and modulation of resistance genes in the host), but carefully drives the readers to reply to two questions: (i) What are the overall effects of Trichoderma on B. cinerea infection in tomato? (ii) Do the main effects of Trichoderma differ based on the tomato species, Trichoderma species, amount, type and duration of treatment? At the same time, this meta-analysis highlights some weak points of the available literature and should be seen as an invitation to improve future works to better the conceptualization and measure.