Maize (Zea mays L.), one of the most important staple crops, is highly vulnerable to fungal infection by Aspergillus and Fusarium species, which produce aflatoxins and fumonisins respectively. Temperature and precipitation interplay in affecting both plant performance and mycotoxin dynamics, but their effects might also depend on plant phenology. Timely identification of risk conditions is therefore essential to address preventive strategies. In 2022 we monitored 20 rainfed maize fields across a pedo-climatic gradient in NE Italy at four phenological stages, namely beginning of stem elongation, end of tassel emergence, milk maturation, dent maturation. At each stage we measured plant functional traits representing maize growth and morpho-physiology; moreover, at harvest, kernel production and mycotoxins accumulation were quantified. All variables were then related to environmental conditions (precipitation, mean temperature, soil texture). Our results showed that both aflatoxins and fumonisins were strongly related to environmental drivers already at stem elongation. The explained variance decreased afterwards, but increased again at harvest. Fumonisins increased when seasonal rainfall was higher, while aflatoxins content was mediated by plant response (plant height and kernel delta 13C). These findings suggest a strong interplay between crop phenology, stress responses, and the occurrence of mycotoxins, shedding new light on the stress-induced vulnerability of plants to mycotoxin production. Stress timing is crucial, as it also affects final harvest conditions and points out possible underlying plant response legacies. We hence stress the importance of early-season monitoring of crops and tailored predictive models to anticipate mycotoxin risk in maize under variable climate scenarios.

A protocol was developed for the isolation and characterization of extracellular vesicles (EVs) from Coffea arabica cell suspension cultures (CSCs). The isolation method involved differential ultracentrifugation of the CSC filtrate, yielding two fractions: the pellet after 100,000×g for 36 min (100k×g) and the pellet obtained from the previous supernatant after 125,000 g for 6 h (125k×g). Both fractions were characterized by size, morphology, and proteomic profiles (ProteomeXchange identifier PXD071909). While no significant differences in average EV size were observed between the two fractions, proteomic analysis revealed distinct quantitative and compositional variations. The 100k×g fraction was enriched in proteins associated with cell periphery, plasma membrane, and extracellular region, whereas the 125k×g fraction predominantly contained proteins from the extracellular region. Proteomic marker analysis confirmed that both fractions contained protein EV markers, such as transmembrane and transport proteins, soluble EV-associated proteins, and proteins targeted to the extracellular environment or cell wall. Conversely, negligible contamination from non-EV-related proteins was detected. Furthermore, transmission electron microscopy (TEM) showed that the average size of the fractions was consistent with that reported for plant EVs. These findings demonstrate that the protocol utilized to isolate EVs from coffee CSC applies to the release of such vesicles without mechanical harsh grinding that leads to tissue/cell rupture and consequent contamination by other cell components. EVs obtained from coffee CSC represent a valuable and scalable platform, paving the way for the development of tools for biotechnological applications.

Mycotoxins in cereals, particularly maize, pose a significant threat to agriculture, worsened by climate change. Therefore, developing effective mitigation strategies are urgently claimed. Plant waste and seaweed extracts offer promising sources of phytochemicals for combating fungal plant pathogens. This study investigated the in vitro antifungal potential and polyphenol composition of hydroalcoholic extracts from plant waste materials and seaweed ( Ailanthus altissima (Mill.) Swingle leaves, Humulus lupulus L. trub, Olea europaea L. leaves and Ulva sp. thallus). With the exception of O. europaea , all extracts inhibited Aspergillus flavus growth, with Ulva sp. showing the highest efficacy (EC 50 = 14.2 mg/mL). Analysis revealed enrichment in glycosylated flavonols and hydroxycinnamic acids across extracts, while Ulva sp. specifically contained rosmarinic acid, p -hydroxybenzoic acid, and uronic acid and sulfate groups, characteristics of ulvan polysaccharides. These results suggest Ulva biomass is a promising botanical source for Aspergillus flavus biocontrol, paving the way for its future application in agriculture and post-harvest systems.

Cover crops can perform multiple ecosystem functions, including weed control, soil quality enhancement and support to pollinators. While the contribution of individual cover crop species or mixtures to each of these functions has been extensively investigated, experiments testing all these ecosystem functions simultaneously to select the best species or mixture overall are rare. In this study, we evaluated the performance of six summer cover crop species in terms of biomass production, weed suppression, soil fertility enhancement potential and support to wild and managed pollinators. Tested species included buckwheat (Fagopyrum esculentum Moench.), white mustard (Sinapis alba L.), berseem clover (Trifolium alexandrinum L.), blue tansy (Phacelia tanacetifolia Benth.), fenugreek (Trigonella foenum-graecum L.) and common vetch (Vicia sativa L.). Field work was carried out in four fields in Northern Italy during the summer months of 2020 and 2021. Buckwheat was identified as the overall best-performing species, by virtue of its high biomass production, ability to control weed growth, and abundant and long-lasting flowering that could support honeybees and hoverflies during a low-resource period without promoting competition. Buckwheat was, however, less promising regarding soil enhancement potential and support to wild bees, highlighting the need to continue searching for complementary cover crop species to be used alongside it in a mixture. Our results could improve cover crop selection schemes, suggesting the necessity for a comprehensive approach aimed at enhancing multiple ecosystem functions in agroecosystems.

Coffea spp. are remarkable sources of phytochemicals, but the lack of a well-defined culture medium aimed at the induction of non-embryogenic and friable callus hampers the establishment of plant cell suspension cultures for large-scale production of valuable compounds. In this paper, we describe a one-medium protocol suitable to obtain both callus and cell suspension cultures from leaves of two elite cultivars of C. arabica . The protocol was developed through an iterative process involving the determination of the best concentration of auxin and cytokinin, their optimal ratio, as well as the most effective molecule of either hormone class. Young leaves were found to be a good and easy-to-use explant source for callus induction and proliferation, provided that a cytokinin was present in association with a chlorinated auxin in a full strength, semi-solid MS medium. The best results were obtained by hormone concentration and combination of 1 mg/L of both kinetin and 2,4,5-trichlorophenoxyacetic acid. The same ratio of these growth regulators was conveniently used for the development and stabilization of cell suspension cultures in liquid MS medium. When grown in darkness, stabilized suspension cultures showed a fine and homogeneous texture, with a 10-fold biomass increase within 25 days and a cell viability > 90%. In addition, the phytochemical profile revealed the presence of the most widely studied coffee compounds. The protocol can be applied to obtain adequate amounts of cell biomass for use in physiological studies concerning the production of secondary metabolites.

Understanding the response of salt marshes to flooding is crucial to foresee the fate of these fragile ecosystems, requiring an upscaling approach. In this study we related plant species and community response to multispectral indices aiming at parsing the power of remote sensing to detect the environmental stress due to flooding in lagoon salt marshes. We studied the response of Salicornia fruticosa (L.) L. and associated plant community along a flooding and soil texture gradient in nine lagoon salt marshes in northern Italy. We considered community (i.e., species richness, dry biomass, plant height, dry matter content) and individual traits (i.e., annual growth, pigments, and secondary metabolites) to analyze the effect of flooding depth and its interplay with soil properties. We also carried out a drone multispectral survey, to obtain remote sensing-derived vegetation indices for the upscaling of plant responses to flooding. Plant diversity, biomass and growth all declined as inundation depth increased. The increase of soil clay content exacerbated flooding stress shaping S. fruticosa growth and physiological responses. Multispectral indices were negatively related with flooding depth. We found key species traits rather than other community traits to better explain the variance of multispectral indices. In particular stem length and pigment content (i.e., betacyanin, carotenoids) were more effective than other community traits to predict the spectral indices in an upscaling perspective of salt marsh response to flooding. We proved multispectral indices to potentially capture plant growth and plant eco-physiological responses to flooding at the large scale. These results represent a first fundamental step to establish long term spatial monitoring of marsh acclimation to sea level rise with remote sensing. We further stressed the importance to focus on key species traits as mediators of the entire ecosystem changes, in an ecological upscaling perspective.

Plant phenotyping on morpho-anatomical traits through image analysis, from microscope images to large-scale acquisitions through remote sensing, represents a low-invasive tool providing insight into physiological and structural trait variation, as well as plant-environment interactions. High phenotype diversity in the genus Amaranthus includes annual weed species with high invasiveness and impact on important summer crops, and nutritive grain or vegetable crops. Identification of morpho-anatomical leaf characters at very young stages across weedy amaranths could be useful for better understanding their performance in agroecosystems. We used an innovative multi-scale approach with phenotype analyses of about 20 single-leaf morphometric traits of four Amaranthus species through processing confocal microscopy and camera acquisitions. The results highlight that determination of leaf traits at different investigation levels highlight species-specific traits at a juvenile stage, which are crucial for plant development, competition and establishment. Specifically, leaf circularity and hairiness Aspect Ratio better discriminated A. tuberculatus from other species. Also, leaf DW, hairiness area and perimeter variables allowed identification of dioecious amaranth species as distinct from monoecious species. The methodology used here provides a promising, reliable and low-impact approach for the functional characterization of phylogenetically related species and for statistical quantification of traits involved in taxonomy and biodiversity studies.

Xylem embolism is one of the possible outcomes of decreasing xylem pressure when plants face drought. Recent studies have proposed a role for non-structural carbohydrates (NSCs) in osmotic pressure generation, required for refilling embolized conduits. Potted cuttings of grapevine Grenache and Barbera, selected for their adaptation to different climatic conditions, were subjected to a drought stress followed by re-irrigation. Stem embolism rate and its recovery were monitored in vivo by X-ray micro-computed tomography (micro-CT). The same plants were further analyzed for xylem conduit dimension and NSC content. Both cultivars significantly decreased Ψpd in response to drought and recovered from xylem embolism after re-irrigation. However, although the mean vessel diameter was similar between the cultivars, Barbera was more prone to embolism. Surprisingly, vessel diameter was apparently reduced during recovery in this cultivar. Hydraulic recovery was linked to sugar content in both cultivars, showing a positive relationship between soluble NSCs and the degree of xylem embolism. However, when starch and sucrose concentrations were considered separately, the relationships showed cultivar-specific and contrasting trends. We showed that the two cultivars adopted different NSC-use strategies in response to drought, suggesting two possible scenarios driving conduit refilling. In Grenache, sucrose accumulation seems to be directly linked to embolism formation and possibly sustains refilling. In Barbera, maltose/maltodextrins could be involved in a conduit recovery strategy via the formation of cell-wall hydrogels, likely responsible for the reduction of conduit lumen detected by micro-CT.

The need to minimise the impact of phytosanitary treatments for disease control boosted researchers to implement techniques with less environmental impact. The development of technologies using molecular mechanisms based on the modulation of metabolism by short dsRNA sequences appears promising. The intrinsic fragility of polynucleotides and the high cost of these techniques can be circumvented by nanocarriers that protect the bioactive molecule enabling high efficiency delivery to the leaf surface and extending its half-life. In this work, a specific protocol was developed aiming to assess the best methodological conditions for the synthesis of low-size chitosan nanoparticles (NPs) to be loaded with nucleotides. In particular, NPs have been functionalised with partially purified Green Fluorescent Protein dsRNAs (GFP dsRNA) and their size, surface charge and nucleotide retention capacity were analysed. Final NPs were also stained with FITC and sprayed on Nicotiana benthamiana leaves to assess, by confocal microscopy, both a distribution protocol and the fate of NPs up to 6 days after application. Finally, to confirm the ability of NPs to increase the efficacy of dsRNA interference, specific tests were performed: by means of GFP dsRNA-functionalised NPs, the nucleotide permanence during time was assessed both in vitro on detached wild-type N. benthamiana leaves and in planta; lastly, the inhibition of Botrytis cinerea on single leaves was also evaluated, using a specific fungal sequence (Bc dsRNA) as the NPs' functionalising agent. The encouraging results obtained are promising in the perspective of long-lasting application of innovative treatments based on gene silencing.

BACKGROUNDIn recent years, biofungicides have drawn increasing interest in vineyards for a more sustainable integrated and copper-limited pest management. Among alternatives, botanicals could represent valuable tools, being rich sources of biologically active compounds. Conversely to the well-known antioxidant and biological properties in relation to health benefits, investigation on bioactivity of hot pungent Capsicum sp. products against fungal phytopathogens in vineyards is still scarce. Therefore, the present study aimed at exploring the biologically active compounds profile of a chili pepper (Capsicum chinense Jacq.) pod extract and its antimicrobial properties against some of the major fungal and Oomycetes pathogens of grapevine, including Botrytis cinerea Pers., Guignardia bidwellii (Ellis) Viala & Ravaz and Plasmopara viticola (Berk. & M.A. Curtis) Berl. & De Toni. RESULTSThe ethyl acetate-extracted oleoresin from the most pungent varieties was rich in capsaicinoids and polyphenols (371.09 and 268.5 mu g mg(-1) dry weight, respectively). Capsaicin and dihydrocapsaicin, hydroxycinnamic and hydroxybenzoic acids and quercetin derivatives were the most abundant, while carotenoids represented only a minor fraction. The oleoresin was efficient to inhibit all three pathogenic fungi and ED50 values were determined, evidencing that G. bidwellii was the more sensitive (0.233 +/- 0.034 mg mL(-1)). CONCLUSIONThe results suggested a potentiality of chili pepper extract for the control of some important grapevine pathogens, their possible application being helpful for the recommended limitation in extensive use of copper in vineyard. The complex mixture of high amounts of capsaicinoids, associated to specific phenolic acids and other minor bioactive components might contribute to the observed antimicrobial action of chili pepper extract. (c) 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Tree ring growth is strictly bound to annual environmental conditions. Therefore, dendrochronology represents a solid tool for investigating the relationship between the whole plant growth and climate at high temporal resolution, especially in the context of ongoing climate change.The temperature increase in the Alpine and Arctic ecosystems has been proven to enhance shrub growth contributing to the Arctic/Alpine greening, while the effects of the interaction between temperature and other climatic variables (e.g. precipitation/snowfall regime) on the shrub growth have often been neglected.With the aim of parsing the relationships between the annual growth of Vaccinium myrtillus L., a key species in the Alpine tundra, temperature, precipitation, snowfall regime (i.e., in terms of temperature-based snowfall, known as snow water equivalent) and their interaction, we analyzed the xylem rings of 100 cross sections of underground bilberry stem, collected along a 500 meters altitude gradient above the tree line and corresponding over a period of 20 years (1995-2015). Furthermore, aiming at linking different ecological scales, we have adopted an ecological upscaling approach. With reference to the area and the period considered, we calculated NDVI using satellite images, and we studied the relationships between this vegetation index, climate, and the anatomical parameters.Our results showed that both number (i.e. ramet age) and mean width of the rings were negatively affected by altitude. The mean annual temperature and snowfall showed significant interaction effects on mean ring width and xylem mean lumen area. Cold years (i.e. low mean annual temperature) and abundant snowfall led to a reduction in the mean ring width, while the snowfall regime did not affect annual ring width in warm years. Xylem mean lumen area was affected by precipitation only in cold years. The mean growth season NDVI increased significantly in the time span considered and showed a positive relationship with the average age of the bilberry community. The interaction between rainfall and average temperature of the vegetative season influenced the NDVI: a negative relationship between vegetation index and rainfall was observed in cooler vegetative seasons, while the relationship was specular in the case of higher temperatures.These results suggest that future scenarios should not overlook the precipitation regime effect by virtue of its possible role in snowpack permanence and drought during the growth season. In this light the shrub expansion could also be curbed by the change of precipitation regime and the increased frequency of extreme climate events (e.g., shift of snowfall regime and intensification of heat waves). Moreover, our findings confirmed the potential use of the remote sensing tool for the understanding of the response of dwarf shrub communities to climate change also for long-term monitoring of these plant communities.

Studying changes in partitioning of dry matter and nonstructural carbohydrates (NSC) content in both aboveground and underground perennial tissues in drought-affected grapevines could provide insights into plant response and carbon allocation strategies during stress periods. The analysis of soluble NSC and starch content in leaf petioles, due to their role in hydraulic segmentation, should also be considered. In the present research, these aspects have been investigated in Merlot grapevines grown in pots and subjected to progressive and increasing soil dehydration, and in well-irrigated vines. Drought conditions caused drastic reduction of shoot elongation and total plant leaf area development in favor of a greater biomass allocation and partitioning towards roots, where most of the NSC reserves were also conserved. Dry matter content of the perennial organs increased in stressed vines due to growth reduction, allocation of carbon reserves and possible anatomical modifications. Vines subjected to drought showed a higher NSC content in petioles, supporting the hypothesis that they are involved as compatible solutes in osmotic adjustments.

The Green New Deal requires a profound transformation of the agricultural sector, which will have to become more sustainable and ensure universal access to healthy food. Thus, it will be essential to introduce radical technological innovations. Nanotechnologies have the potential to produce a significant boost to the improvement of the food system. Within this context, in the next years, a strong challenge will need to be faced regarding developing new and more efficient uses of nutrients in agriculture, being the nutrient use efficiency (NUE) paramount in sustaining high crop productivity without depleting biodiversity, and altering both the natural and agricultural systems. Nutrients leaching causes environmental pollution and water eutrophication, while nutrient excess favors pest and weed widespread. Therefore, it will be mandatory to improve plant nutrition efficiency without affecting agricultural productivity and economic sustainability. A promising alternative consists of the introduction of the so-called nanomaterial enhanced fertilizers and plant growth stimulators. Such innovation includes nanotechnological solutions that can improve nutrient delivery for a more finely tuned, accurate, and saving-resources distribution of nutrients. This review provides a critical view of the latest advances in nanofertilizer research, mainly referring to nano-hydroxyapatite, silica nanoparticles, and chitosan-derived nanostructures.

Premise Despite great attention given to the relationship between plant growth and carbon balance in alpine tree species, little is known about shrubs at the treeline. We hypothesized that the pattern of main nonstructural carbohydrates ( NSC s) across elevations depends on the interplay between phenotypic trait plasticity, plant–plant interaction, and elevation. Methods We studied the pattern of NSC s (i.e., glucose, fructose, sucrose, and starch) in alpine stands of Vaccinium myrtillus (above treeline) across an elevational gradient. In the same plots, we measured key growth traits (i.e., anatomical stem features) and shrub cover, evaluating putative relationships with NSC s. Results Glucose content was positively related with altitude, but negatively related with shrub cover. Sucrose decreased at high altitude and in older populations and increased with higher percentage of vascular tissue. Starch content increased at middle and high elevations and in stands with high shrub cover. Moreover, starch content was negatively related with the number of xylem rings and the percentage of phloem tissue, but positively correlated with the percentage of xylem tissue. Conclusions We found that the increase in carbon reserves across elevations was uncoupled from plant growth, supporting the growth limitation hypothesis, which postulates NSC s accumulate at high elevation as a consequence of low temperature. Moreover, the response of NSC content to the environmental stress caused by elevation was buffered by phenotypic plasticity of plant traits, suggesting that, under climate warming conditions, shrub expansion due to enhanced plant growth would be pronounced in old but sparse stands.

The study of morphological and physiological responses of shrubs to climate is crucial for the understanding of future scenarios regarding climate change. In this light, studying shrub growth and physiological acclimation along an elevation gradient might be insightful. The phenolic metabolic pathway represents a powerful tool to interpret such processes. In the South-Eastern Alps, we investigated the relationships between elevation, plant traits (i.e. age, xylem ring width, annual shoot length), plant-plant interaction (i.e. shrub cover) and flavonoids in Vaccinium myrtillus L. (leaves, berries) in stands above the treeline. The relationships were parsed within causal networks using a confirmatory path analysis. Elevation was the main driver of V. myrtillus growth, having both direct and indirect effects on the leaf flavonoid content, but this was less evident for berries. In particular, the content of foliar flavonoids showed a peak at mid-elevation and where the growth of xylem rings was intermediate, while it decreased in stands with higher shoot length. Flavonoid content variability of both leaves and berries was affected by elevation and shoot length. In berries, flavonoid variability was further related to all growth traits and shrub cover. These findings evidence that flavonoid content is influenced by both elevation and growth traits of V. myrtillus, often showing non-linear relationships. These results suggest a trait-mediated response of this plant to climate conditions as a result of trade-offs between plant growth, plant defence, environmental stress and nutrient/resource availability.

Plant growth and development is significantly influenced by phytohormones – endogenous molecules present naturally in plants. The best known plant hormones are auxins and cytokinins. This study examined the possible effect of externally applied plant hormone analogues (growth regulators): 1-naphthyl acetic acid (NAA) and 6-benzyl aminopurine (BAP) on industrial fibre hemp (Cannabis sativa L., variety Bialobrzeskie). Plants were treated with three different concentrations of NAA (5, 10 and 20 mg/l) and three different concentrations of BAP (10, 25 and 50 mg/l). Morphological and physiological characteristics, such as apical dominance, shoot branching, fibre properties, and flavonoid content were evaluated. The chosen variety of hemp had a significant response to exogenous application of growth regulators, as has been observed with other plant species. Most notably, completely understood and controlled synthetic auxin tretament has a potential to increase the bark fibre yield of hemp.

The mitochondrial F-ATP synthase is responsible for coupling the transmembrane proton gradient, generated through the inner membrane by the electron transport chain, to the synthesis of ATP. This enzyme shares a basic architecture with the prokaryotic and chloroplast ones, since it is composed of a catalytic head (F1), located in the mitochondrial matrix, a membrane-bound part (FO), together with a central and a peripheral stalk. In this review we compare the structural and functional properties of F-ATP synthase in plant mitochondria with those of yeast and mammals. We also present the physiological impact of the alteration of F-ATP synthase in plants, with a special regard to its involvement in cytoplasmic male sterility. Furthermore, we show the involvement of this enzyme in plant stress responses. Finally, we discuss the role of F-ATP synthase in shaping the curvature of the mitochondrial inner membrane and in permeability transition pore formation.

Hemp (Cannabis sativa L.) for industrial use is often considered as a renewable resource for cultivation in polluted areas, on one hand, for the purpose of possible remediation of soil and, on the other hand, for wide options of the possible use of plant material after the harvest in such areas, namely hemp fiber. This study summarizes the effects of landfill leachate irrigation on agronomic parameters and fiber properties in two cultivars of hemp has grown and harvested in two consecutive seasons. Cultivar Bialobrzeskie shows more promising results in terms of total fiber content and phloem fiber content, while it tends to sacrifice the density of both xylem and phloem fiber in comparison to cultivar Monoica. The two cultivars also demonstrate different sensitivity and responses to the presence of heavy metals, namely zinc and chromium.

In grapevine, the anatomy of xylem conduits and the non-structural carbohydrates (NSCs) content of the associated living parenchyma are expected to influence water transport under water limitation. In fact, both NSC and xylem features play a role in plant recovery from drought stress. We evaluated these traits in petioles of Cabernet Sauvignon (CS) and Syrah (SY) cultivars during water stress (WS) and recovery. In CS, the stress response was associated to NSC consumption, supporting the hypothesis that starch mobilization is related to an increased supply of maltose and sucrose, putatively involved in drought stress responses at the xylem level. In contrast, in SY, the WS-induced increase in the latter soluble NSCs was maintained even 2 days after re-watering, suggesting a different pattern of utilization of NSC resources. Interestingly, the anatomical analysis revealed that conduits are constitutively wider in SY in well-watered (WW) plants, and that water stress led to the production of narrower conduits only in this cultivar.

The Nutrient Use Efficiency in intensive agriculture is lower than 50% for macronutrients. This feature results in unsustainable financial and environmental costs. Nanofertilizers are a promising application of nanotechnology in agriculture. The use of nanofertilizers in an efficient and safe manner calls for knowledge about the actual effects of nanoproducts on the plant metabolism and eventually on the carrier release kinetics and nutrient accumulation. Hydroxyapatite (Ca10(PO4)6(OH)2) nanoparticles (nHA) have an interesting potential to be used as nanofertilizers. In this study, the effects of different nHA solutions stabilized with carboxymethylcellulose (CMC) were evaluated on germination, seedling growth, and metabolism of Solanum lycopersicum L., used as model species. Our observations showed that the percentage germination of S. lycopersicum is not influenced by increasing concentrations of nHa, while root elongation is strongly stimulated. Tomato plants grown in hydroponics in the presence of nHA have not suffered phytotoxic effects. We conclude that nHA had nontoxic effects on our model plant and therefore it could be used both as a P supplier and carrier of other elements and molecules.