Effect of a wood-based carrier of Trichoderma atroviride SC1 on the microorganisms of the soil

Wood pellets can sustain the growth of Trichoderma spp. in soil; however, little is known about their side effects on the microbiota. The aims of this study were to evaluate the effect of wood pellets on the growth of Trichoderma spp. in bulk soil and on the soil microbial population’s composition and diversity. Trichoderma atroviride SC1 coated wood pellets and non-coated pellets were applied at the level of 10 g∙kg−1 of soil and at the final concentration of 5 × 103 conidia∙g−1 of soil and compared to a conidial suspension applied at the same concentration without the wood carrier. Untreated bulk soil served as a control. The non-coated wood pellets increased the total Trichoderma spp. population throughout the experiment (estimated as colony-forming unit g−1 of soil), while wood pellets coated with T. atroviride SC1 did not. The wood carrier increased the richness, and temporarily decreased the diversity, of the bacterial population, with Massilia being the most abundant bacterial genus, while it decreased both the richness and diversity of the fungal community. Wood pellets selectively increased fungal species having biocontrol potential, such as Mortierella, Cladorrhinum, and Stachybotrys, which confirms the suitability of such carriers of Trichoderma spp. for soil applicatio

First record of quagga mussel, Dreissena bugensis Andrusov, 1897, in Italy: morphological and genetic evidence in Lake Garda

Here, we report the first record of quagga mussel, Dreissena bugensis Andrusov, 1897, in Italy. This mollusc is native of the Dnieper River drainage of Ukraine and is one of the most aggressive invaders in freshwater ecosystems. The spread of quagga mussels throughout Europe and Northern America begun during the 1940s and 1989, respectively. Individuals of quagga mussel were identified in February and March 2022 in two stations located in the shallow (Bardolino) and deeper basins (Castelletto di Brenzone) of Lake Garda. Samples, collected with an Eckman grab, allowed identifying individuals of quagga mussel attached on macrophytes, stones and other mollusc shells. The identification of the individuals was carried out both through the analysis of morphological characters and genetic and phylogenetic analyses using the mitochondrial COI gene. The discovery of quagga mussel is the last of a long series of reports of non-indigenous species introduced into Lake Garda. Lacking direct connection by rivers or canals with other waterbodies colonized by D. bugensis at the northern side of the Alps, a more probable cause of introduction of this new species into Lake Garda can be due to unintentional overland transport through recreational boats and fishing gear. With this new discovery, Lake Garda has confirmed its pivotal role as a southern Alpine corridor for the introduction of non-indigenous species previously established at the northern border of the Alps. Considering its high colonization rate and compared with other invasion patterns observed in Europe and North America, it can be assumed that D. bugensis will soon establish itself with dominant populations throughout Lake Garda. At the same time, it can also be assumed that it will soon spread to other Italian water bodie

Reduced fire blight susceptibility in apple cultivars using a high-efficiency CRISPR/Cas9-FLP/FRT-based gene editing system

The bacterium Erwinia amylovora, the causal agent of fire blight disease in apple, triggers its infection through the DspA/E effector which interacts with the apple susceptibility protein MdDIPM4. In this work, an MdDIPM4 knock-out has been produced in two Malus x domestica susceptible cultivars using the CRISPR/Cas9 system delivered via Agrobacterium tumefaciens. Fifty-seven transgenic lines were screened to identify CRISPR/Cas9-induced mutations. An editing efficiency of 75% was obtained. Seven edited lines with a loss-of-function mutation were inoculated with the pathogen. Highly significant reduction of susceptibility was observed compared to control plants. Sequencing of 5 potential off-target sites revealed no mutation event. Moreover, our construct contained a heat shock-inducible FLP/FRT recombination system designed specifically to remove the T-DNA harbouring expression cassettes for CRISPR/Cas9, marker gene and FLP itself. Six plant lines with reduced susceptibility to the pathogen were heat-treated and screened by real-time PCR to quantify the exogenous DNA elimination. The T-DNA removal was further validated by sequencing in one plant line. To our knowledge, this work demonstrates for the first time the development and application of a CRISPR/Cas9-FLP/FRT gene editing system for the production of edited apple plants carrying a minimal trace of exogenous DN

Genome sequencing provides new insights on the distribution of Erwinia amylovora lineages in northern Italy

Erwinia amylovora is a Gram-negative bacterium that colonizes a wide variety of plant species causing recurrent local outbreaks of fire blight in crops of the Rosaceae family. Recent genomic surveys have documented the limited genomic diversity of this species, possibly related to a recent evolutionary bottleneck and a strong correlation between geography and phylogenetic structure of the species. Despite its economic importance, little is known about the genetic variability of co-circulating strains during local outbreaks. Here, we report the genome sequences of 82 isolates of E. amylovora, collected from different host plants in a period of 16 years in Trentino, a small region in the Northeastern Italian Alps that has been characterized by recurrent outbreaks of fire blight in apple orchards. While the genome isolated before 2018 are closely related to other strains already present in Europe, we found a novel subclade composed only by isolates that were sampled starting from 2018 and demonstrate that the endemic population of this pathogen can be composed by mixture of strain

Intergenerational transfer of persistent bacterial communities in female Nile tilapia

5openInternationalInternational coauthor/editorResident microbial communities that can support various host functions play a key role in their development and health. In fishes, microbial symbionts are vertically transferred from the parents to their progeny. Such transfer of microbes in mouthbrooder fish species has not been reported yet. Here, we employed Nile tilapia (Oreochromis niloticus) to investigate the vertical transmission of microbes across generations using a 16S rRNA amplicon sequencing approach, based on the presence of bacteria in different generations. Our analysis revealed that the core microbiome in the buccal cavity and posterior intestine of parents shapes the gut microbiome of the progeny across generations. We speculate that the route of this transmission is via the buccal cavity. The identified core microbiome bacteria, namely Nocardioides, Propionibacterium, and Sphingomonas have been reported to play an essential role in the health and development of offspring. These core microbiome members could have specific functions in fish, similar to mammals.openAbdelhafiz, Yousri; Fernandes, Jorge M. O.; Donati, Claudio; Pindo, Massimo; Kiron, ViswanathAbdelhafiz, Y.; Fernandes, J.M.O.; Donati, C.; Pindo, M.; Kiron, V

A SNP transferability survey within the genus Vitis

<p>Abstract</p> <p>Background</p> <p>Efforts to sequence the genomes of different organisms continue to increase. The DNA sequence is usually decoded for one individual and its application is for the whole species. The recent sequencing of the highly heterozygous <it>Vitis vinifera </it>L. cultivar Pinot Noir (clone ENTAV 115) genome gave rise to several thousand polymorphisms and offers a good model to study the transferability of its degree of polymorphism to other individuals of the same species and within the genus.</p> <p>Results</p> <p>This study was performed by genotyping 137 SNPs through the SNPlex™ Genotyping System (Applied Biosystems Inc.) and by comparing the SNPlex sequencing results across 35 (of the 137) regions from 69 grape accessions. A heterozygous state transferability of 31.5% across the unrelated cultivars of <it>V. vinifera</it>, of 18.8% across the wild forms of <it>V. vinifera</it>, of 2.3% among non-<it>vinifera Vitis </it>species, and of 0% with <it>Muscadinia rotundifolia </it>was found. In addition, mean allele frequencies were used to evaluate SNP informativeness and develop useful subsets of markers.</p> <p>Conclusion</p> <p>Using SNPlex application and corroboration from the sequencing analysis, the informativeness of SNP markers from the heterozygous grape cultivar Pinot Noir was validated in <it>V. vinifera </it>(including cultivars and wild forms), but had a limited application for non-<it>vinifera Vitis </it>species where a resequencing strategy may be preferred, knowing that homology at priming sites is sufficient. This work will allow future applications such as mapping and diversity studies, accession identification and genomic-research assisted breeding within <it>V. vinifera</it>.</p

Diet-driven mercury contamination is associated with polar bear gut microbiota

7openInternationalInternational coauthor/editorThe gut microbiota may modulate the disposition and toxicity of environmental contaminants within a host but, conversely, contaminants may also impact gut bacteria. Such contaminant-gut microbial connections, which could lead to alteration of host health, remain poorly known and are rarely studied in free-ranging wildlife. The polar bear (Ursus maritimus) is a long-lived, wide-ranging apex predator that feeds on a variety of high trophic position seal and cetacean species and, as such, is exposed to among the highest levels of biomagnifying contaminants of all Arctic species. Here, we investigate associations between mercury (THg; a key Arctic contaminant), diet, and the diversity and composition of the gut microbiota of polar bears inhabiting the southern Beaufort Sea, while accounting for host sex, age class and body condition. Bacterial diversity was negatively associated with seal consumption and mercury, a pattern seen for both Shannon and Inverse Simpson alpha diversity indices (adjusted R2 = 0.35, F1,18 = 8.00, P = 0.013 and adjusted R2 = 0.26, F1,18 = 6.04, P = 0.027, respectively). No association was found with sex, age class or body condition of polar bears. Bacteria known to either be involved in THg methylation or considered to be highly contaminant resistant, including Lactobacillales, Bacillales and Aeromonadales, were significantly more abundant in individuals that had higher THg concentrations. Conversely, individuals with higher THg concentrations showed a significantly lower abundance of Bacteroidales, a bacterial order that typically plays an important role in supporting host immune function by stimulating intraepithelial lymphocytes within the epithelial barrier. These associations between diet-acquired mercury and microbiota illustrate a potentially overlooked outcome of mercury accumulation in polar bears.openWatson, S.; McKinney, M.A.; Pindo, M.; Bull, M.; Atwood, T.C.; Hauffe, H.C.; Perkins, S.E.Watson, S.; Mckinney, M.A.; Pindo, M.; Bull, M.; Atwood, T.C.; Hauffe, H.C.; Perkins, S.E

Grapevine (Vitis vinifera L.) varietal assortment and evolution in the Marche region (central Italy)

14openInternationalItalian coauthor/editorItaly is one of the richest countries in terms of grapevine varietal assortment, and the Marche region in central Italy has an ancient winegrowing tradition. Increasing interest in autochthonous grapevine varieties prompted efforts to recover and identify local minor germplasm also in this region, and to search for pedigree relationships and determine the evolution of varietal assortment. In the present study this was done using nuclear and chloroplast microsatellite markers and SNP markers from the Vitis18kSNP chip. Eighteen new genotypes were found, of which seventeen belonged to well-known, less known and even unknown vines found to be specific to the Marche region. The rearranged pedigree highlighted the complex intertwining relationships between Marche varieties. Second-degree relationships were also derived. Some minor Marche varieties have increased the number of parent-offspring related members of Garganega, Sangiovese, Crepolino/Visparola and Sciaccarello, which are varieties already recognised as founders or recurrent parents of many Italian cultivars. Crepolino/Visparola was shown to be a key variety in the evolution of the Marche varietal assortment, having played the role of parent and grandparent, as explained by the presence of this genotype in the region in ancient times. Surprisingly, Semidano, a well-known Sardinian variety, played a clear role as parent or grandparent of three minor Marche varieties, testifying to its presence in central Italy in ancient times. Incrocio Bruni 54 was confirmed as an offspring of Sauvignon and Verdicchio, as declared by the breeder. The parentage of Lacrima was completed: this variety was found to be a spontaneous cross between Nera Rada and Aleatico. A dendrogram of genetic similarity clearly resembled the groups defined with the pedigree reconstruction and it gave an indication of the genetic similarity of the varieties excluded from the strictest parentage links.openCrespan, Manna; Migliaro, Daniele; Larger, Simone; Pindo, Massimo; Palmisano, Massimo; Manni, Alvise; Manni, Elisa; Polidori, Enzo; Sbaffi, Francesco; Silvestri, Quintilio; Silvestroni, Oriana; Velasco, Riccardo; Virgili, Settimio; Camilli, GiuseppeCrespan, M.; Migliaro, D.; Larger, S.; Pindo, M.; Palmisano, M.; Manni, A.; Manni, E.; Polidori, E.; Sbaffi, F.; Silvestri, Q.; Silvestroni, O.; Velasco, R.; Virgili, S.; Camilli, G

Metabarcoding analysis of the bacterial and fungal communities during the maturation of preparation 500, used in biodynamic agriculture, suggests a rational link between horn and manure

Horn manure (Preparation 500) is a product used in the practice of biodynamic agriculture. It is obtained by an underground fermentation of cow fecal material incubated in cow horns for several months. The product is used as spray treatment meant to increase soil fertility. In the present report, we analyzed the successional changes in bacterial and fungal communities throughout the process of horn manure maturation by high throughput sequencing of ribosomal 16S (bacterial) and ITS (fungal) gene markers. Marked shifts in the microbial community were seen involving a general decrease from a Firmicutes dominated material to a product transiently enriched in Proteobacteria and later in Actinobacteria, mostly within the Nocardioidaceae family. In the fungal community evolution, the most abundant taxon in the starting fecal material resulted a member of the Onygenales order, known to specifically degrade keratin. Its abundance in the intestine is explained by the fact that keratin, which is also the structural component of hairs and horns, is found in all epithelial layers, including gut mucosae. This occurrence suggests a link of enzymatic/catabolic nature between manure and horn