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Olive reproductive biology: implications for yield, compatibility conundrum, and environmental constraints
No full textOlive (Olea europaea L.) is an important Mediterranean tree species with a longstanding history of cultivation, boasting a diverse array of local cultivars. While traditional olive orchards are valued for their cultural and aesthetic significance, they often face economic sustainability challenges in the modern context. The success of both traditional and newly introduced cultivars (e.g. those obtained by cross-breeding) is hindered by self-incompatibility, a prevalent issue for this species that results in low fruit set when limited genetic diversity is present. Further, biological, environmental, and agronomic factors have been shown to interlink in shaping fertilization patterns, hence impacting on the final yield. Climatic conditions during pollination, such as excessive rainfall or high temperatures, can further exacerbate the problem. In this work, we provide an overview of the various factors that trigger the phenomenon of suboptimal fruit set in olive trees. This work provides a comprehensive understanding of the interplay among these factors, shedding light on potential mechanisms and pathways that contribute to the observed outcomes in the context of self-incompatibility in oliv
Combining Vitis OneGene causality approach with phylogenetic and cistrome analyses to study the laccase, dirigent and peroxidase gene networks
No full textThe availability of transcriptomic data organized in coherent databases and the development of causal inference methods have paved the way to gene network analysis in grapevine. The identification and visualization of gene-to-gene interactions as networks can contribute to several aims, such as the identification of hub genes or modules, the prediction of gene function, the integration of different -omics data and the comparison of the networks found across species. OneGenE, an in house developed causality-based data mining tool, has been applied to the Vitis transcriptomic data set VESPUCCI to produce a list of directly interacting genes, for each gene of the grapevine genome. Due to the computational power requirement of the OneGenE algorithm, it has been run as part of the gene@home project, a distributed computing project relying on thousands of volunteers computers by means of the TN-Grid, an infrastructure based on BOINC system. Finally, bioinformatic tools have been built in house to reconstruct association gene networks using the OneGenE generated lists. All this information and analysis tools are now available to the community through the Vitis OneGenE website. Here, we analyse the OneGenE association networks of three gene families putatively involved in lignin biosynthesis and integrate this information with phylogenetic analyses and DNA affinity purification sequencing (DAP-seq) data. The enzymes laccase, peroxidase and Dirigent proteins, present in the grapevine genome as large gene families, catalyse the final steps of monolignol polymerization in lignin biosynthesis. However, our results strongly suggest the evolutionary divergence of a group of them possibly involved in the oligomerization of resveratrol to produce oligomeric stilbenoids, phytoalexins with antifungal properties. Although experimental validation is undoubtedly required to confirm these findings, they represent an interesting example of how bioinformatic analyses based on the reuse of existing data can support and accelerate knowledge discovery in grapevine
Dispersal of antibiotic resistant microbes in alpine snow and its consequences
Get PDFAntibiotic resistance is considered one of the greatest global challenges of the 21st century. However, relatively little is known about its distribution outside urban areas, and especially the cryosphere. These regions, often regarded as one of the most pristine ones on Earth, provide an interesting environment for studying both intrinsic resistances and estimating the extent of anthropogenic pollution by antibiotic resistance. The impact of humans on the spread of resistant microorganisms in the cryosphere has been largely unexplored. Glacier regions are not isolated areas, and the downstream effects on the circulation of resistant microorganisms and their resistance genes remain unclear. The lack of standardized and comparable methods for such investigations poses a particular challenge for determining the resistome of the cryosphere. This work addresses these existing knowledge gaps and explores the potential of microorganisms in the cryosphere to survive antibiotics in toxic concentrations, as well as the role of anthropogenic influence. (...
Volatile and sensory profile of cerumen, plant resin deposit, and propolis of a Tetragonisca angustula (Latreille 1811) nest from Merida, Venezuela
No full textA colony of Tetragonisca angustula nested in a damaged 30 cm diameter porcelain Büchner funnel in a garden. This pharmaceutical hive attracted the attention of J.M.F. Camargo†, who was invited to a conference at the Faculty of Pharmacy, who then transferred the colony to a wooden hive. Six plant resin-beeswax-based materials were collected from the nest. Four types of cerumen: (1) Entrance tube. (2) Involucrum of the brood. (3) Pillars by the food reserve pots. (4) Empty honey pots. (5) Irregular resin deposited on the upper wall. (6) Layered propolis deposited on the indoor lid of the hive. These materials were described for visual, tactile, odor-aroma, and taste attributes. Sensory perception was assessed using an intensity scale of 0–3. The brittle involucrum had the strongest smell. Stickiness to teeth bite was higher in the indoor cover propolis of the hive, but the entrance tube stuck more to the fingertips. Colors varied from tortilla to brunette. The involucrum was not as malleable as the other resin-based materials analyzed. Volatile organic compounds (VOCs) from different chemical classes were identified and quantified by HS-SPME/GC-MS: 11 acids, 7 aldehydes, 16 alcohols, 16 esters, 8 ketones, 17 monoterpenes, 5 oxides, 11 sesquiterpenes, and 4 compounds from other classes; 52/95 of these VOCs were detected in the six beeswax-plant resin-based materials of T. angustula nest, as core VOC
Gas nanosensors for quality assessment of food products: economic devices that can be integrated into the production and distribution chain
Get PDFThis PhD project arises from the growing awareness of food quality and safety on the part of citizens and institutions. The increase in the population to feed, the lengthening of the production and distribution chains and the socio-economic risks of a poor diet make it crucial to monitor the quality of food from the producer to the consumer. Traditional methods (sensory panels and laboratory analytical techniques) are too expensive and above all slow to evaluate the quality of fresh foods that deteriorate over the course of a few hours. In this context, it is crucial to develop monitoring devices that are cheap, rapid and non-invasive, in order to be able to evaluate the quality of food products extensively and constantly. Solid-state gas sensors are an ideal candidate, as they are inherently non-invasive and inexpensive. In this context, the project focused on chemoresistive sensors based on semiconductor metal oxides, which are among the simplest and most performing, and have the advantage of being sensitive to almost all gases and VOCs. Initially, nanostructures of different materials (n- and p-type semiconductors) and of different morphologies (nanowires and nanosheets) were studied in order to investigate the performance of individual sensors. In this way, some devices have been optimized with respect to the detection of possible biomarkers of the degradation of specific foods. The sensors have demonstrated a rapid response (from a few seconds to a minute), an intense response and above all a very low detection limit (less than 1ppmv, in some cases a few tens of ppbv), important for agri-food applications. This approach is the simplest since it requires a single sensor that is selective towards a certain molecule (ammonia, ethylene...) which can be considered the only important information parameter in a certain application. In most cases, however, the gaseous emission of a food is composed of a large quantity of volatile compounds, and the low selectivity of resistive sensors makes it difficult to discriminate the molecules most informative regarding the degradation process. For this reason, in the second part of the PhD we used the sensors developed up to then to create electronic noses. Exploiting the dimensions of nanostructures, we have developed a new concept of thermal electronic nose, i.e. with sensors of the same material, but within a thermal gradient. In this way, by exploiting multivariate statistical analysis and machine learning techniques, the devices acquired a greater ability to discriminate and quantify the different gases. The electronic noses have shown that they can perfectly recognize the different gases tested (100%) and estimate their concentration with an error of a few ppmv. Measurements in the laboratory are very useful for testing the performance parameters of sensors and electronic noses, as they make it possible to evaluate the correctness of the classification and the error in estimating the concentration of any gas. On the other hand, measuring the emissions of fresh food is different, as the concentrations are not known, and therefore a different approach is needed. The final stage of the project involved using electronic noses to assess the freshness of certain agri-food products. As the developed sensors were particularly sensitive to ammonia, it was decided to study the degradation of meat and fish, where this gas is an important marker. The electronic noses have been able to accurately recognize the meat from the fish (> 95%), and evaluate the state of degradation by giving a very accurate estimate of the microbial count (>95%), responding in a very short time (tens of seconds). The miniaturized electronic noses developed during this PhD project have therefore successfully demonstrated to be a rapid and non-invasive cross-sectional tool for assessing the freshness of agri-food product
2-class Grapevine Pest Dataset of Scaphoideus titanus and Orientus ishidae on yellow Sticky traps for Insect Detection
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This tree is on fire: a review on the ecology of Erwinia amylovora, the causal agent of fire blight disease
Get PDFFire blight represents a great threat to apple and pear production worldwide. The ability of its causal agent, Erwinia amylovora, to spread rapidly in the host plants makes this devastating disease difficult to manage. Copper and antibiotics are still the most effective solutions to control fire blight, although their application contribute to environmental pollution and to the development of E. amylovora resistant populations. Thus, there is an urgent need to find new alternatives to such plant protection products. In this review, we summarized what is known on E. amylovora biology, as the knowledge of the plant pathogen biology is essential to develop eco-friendly management strategies. Notably, the presence of E. amylovora alone does not necessarily result in the disease development as it is the final outcome of multiple interactions established between E. amylovora cells, flower microbiota, plant host, insect vectors and environment. For instance, specific humidity and temperature create the suitable conditions for E. amylovora to grow and reach the specific cell density needed for plant infection. Once fire blight develops, insects act as potential vectors of E. amylovora, playing a role in the dispersal of the disease. The host plant represents an important factor as its susceptibility varies among the species belonging to the Rosaceae family. Recent studies showed apple flower microbiota might promote or hinder the infection progress, thus representing a possible source of new biocontrol agents effective in controlling E. amylovor
Dominance and rarity in tree communities across the globe: patterns, predictors and threats
Get PDFEcological and anthropogenic factors shift the abundances of dominant and rare tree species within local forest communities, thus affecting species composition and ecosystem functioning. To inform forest and conservation management it is important to understand the drivers of dominance and rarity in local tree communities. We answer the following research questions: (1) What are the patterns of dominance and rarity in tree communities? (2) Which ecological and anthropogenic factors predict these patterns? And (3) what is the extinction risk of locally dominant and rare tree species
