1,720,995 research outputs found
Preserving the grape-associated microbiota to improve the hologenome plasticity and adaptability to climate change
No full textPlants’ genetic improvement has been exploited for a long time as an important approach to cope with environmental stresses (both biotic and abiotic) or to improve traits useful for human needs. As a shortcoming of the incessant selection of genomic plant traits, and the considerable number of inputs needed to sustain the selected genotypes, nowadays a negative impact on the biodiversity of the plant-associated microbes can be observed. It is worth noting that these microbes represent an extended plant genome, termed as the hologenome, which can play a pivotal role in plant adaptation to several stresses. In recent years, many researchers have increasingly focused their attention on the isolation, characterization, and preservation of plant-associated microbes (termed as the holobiont). In this context a publicly available repository of grapevine-associated microbes has been established with the aim of preserving the microbial biodiversity and exploit such arsenal to improve viticulture sustainability and resilience. To reach such objective, we attempted the manipulation of the holobiont/hologenome through the development of tailored synthetic microbial communities (SynComs). Specifically, a collection of endophytic bacterial isolates obtained from grapevine woody tissues has been exploited to produce an ad-hoc inoculum comprising potential biological control agents to counteract the esca syndrome. Employing a comprehensive approach that integrates molecular, biochemical, and eco-physiological assessments, we demonstrated that SynCom treatment influenced the trade-off between plant growth and defence features. Plants inoculated with SynComs redirected their energy allocation towards defence pathways, thereby affecting their physiological performance. Our findings suggest that a holistic approach considering both the attributes of the bacteria and their impacts on plant growth and defence mechanisms can unveil the intricate mechanisms underlying plantendophyte interactions. Despite the enormous potential of SynComs, important information is still lacking, and it is crucial to shed light on the ‘dark-side effects’ of SynCom applications with the aim to harness their potential with a refined awareness
Abiotic Stress and Belowground Microbiome: The Potential of Omics Approaches
No full textNowadays, the worldwide agriculture is experiencing a transition process toward more sustainable production, which requires the reduction of chemical inputs and the preservation of microbiomes’ richness and biodiversity. Plants are no longer considered as standalone entities, and the future of agriculture should be grounded on the study of plant-associated microorganisms and all their potentiality. Moreover, due to the climate change scenario and the resulting rising incidence of abiotic stresses, an innovative and environmentally friendly technique in agroecosystem management is required to support plants in facing hostile environments. Plant-associated microorganisms have shown a great attitude as a promising tool to improve agriculture sustainability and to deal with harsh environments. Several studies were carried out in recent years looking for some beneficial plant-associated microbes and, on the basis of them, it is evident that Actinomycetes and arbuscular mycorrhizal fungi (AMF) have shown a considerable number of positive effects on plants’ fitness and health. Given the potential of these microorganisms and the effects of climate change, this review will be focused on their ability to support the plant during the interaction with abiotic stresses and on multi-omics techniques which can support researchers in unearthing the hidden world of plant–microbiome interactions. These associated microorganisms can increase plants’ endurance of abiotic stresses through several mechanisms, such as growth-promoting traits or priming-mediated stress tolerance. Using a multi-omics approach, it will be possible to deepen these mechanisms and the dynamic of belowground microbiomes, gaining fundamental information to exploit them as staunch allies and innovative weapons against crop abiotic enemies threatening crops in the ongoing global climate change context
Microscale analysis of soil characteristics and microbiomes reveals potential impacts on plants and fruit: vineyard as a model case study
Full text linkAims: Soil microbiome roles in agriculture is becoming more and more important. This importance is also reflected on the way plants are seen: complex organisms formed by the plant itself plus the microbes inhabiting its tissues, including the ones on the surface of every organ and the ones adhered or in proximity to the roots. In addition, as already demonstrated, the microbial community associated with a specific soil is able to predetermine the health status of crops. For all the above mentioned reasons, defining the microbial composition of agricultural soils and the factors driving the assemblage is pivotal to achieve more sustainable agriculture and viticulture. Methods: We aimed to investigate how the soil geological characteristics influence the microbiome composition associated with close geographically related vineyards. Moreover, we studied both the top (15 cm in depth) and deep (120 cm in depth) soil layers as anthropically influenced and almost-undisturbed soil, respectively. Results: We observed slightly different microbial communities despite the close geographical proximity of the two vineyards, which is considered one of the main determinants of the soil microbiome composition. In addition, we found that the geological characteristics of the two soils influence both the root distribution and the accumulation of pathogen- and symbiont-related genera. Sensory profiles of the Grillo wines from the two different soils confirmed the tight link between soil origin and wine traits. Conclusions: In the present study, we highlight that the geological characteristics of soil can influence soil microbial composition and assemblage in close geographically related vineyards, with a potential effect on wine features
Aspergillus goes viral: Ecological insights from the geographical distribution of the mycovirome within an aspergillus flavus population and its possible correlation with aflatoxin biosynthesis
Full text linkMicrobial multi-level interactions are essential to control the success of spreading and survival of most microbes in natural environments. Phytopathogenic mycotoxigenic fungal species, such as Aspergillus flavus, represent an important issue in food safety. Usually, non-toxigenic strains are exploited for biocontrol strategies to mitigate infections by toxigenic strains. To comprehend all the biological variables involved in the aflatoxin biosynthesis, and to possibly evaluate the interplay between A. flavus toxigenic and non-toxigenic strains during intraspecific biocompetition, the “virological” perspective should be considered. For these reasons, investigations on mycoviruses associated to A. flavus populations inhabiting specific agroecosystems are highly desirable. Here, we provide the first accurate characterization of the novel mycovirome identified within an A. flavus wild population colonizing the maize fields of northern Italy: a selection of A. flavus strains was biologically characterized and subjected to RNAseq analysis, revealing new mycoviruses and a peculiar geographic pattern distribution in addition to a 20% rate of infection. More interestingly, a negative correlation between viral infection and aflatoxin production was found. Results significantly expanded the limited existent data about mycoviruses in wild A. flavus, opening new and intriguing hypotheses about the ecological significance of mycoviruses
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Water deficit regimes trigger changes in valuable physiological and phytochemical parameters in Helichrysum petiolare Hilliard & B.L. Burtt
Full text linkThe genus Helichrysum Miller is a source of many bioactive metabolites commonly used in traditional medicine. In particular, Helichrysum petiolare Hilliard & B.L. Burtt shows activities as antiseptic, anti-inflammatory and in the control of anxiety disorder. Biosynthesis and accumulation of secondary metabolites is a defense mechanism of plants and it is strictly influenced by the surrounding environmental conditions. In this study, drought was imposed on H. petiolare (HEL008 clone CREA-Sanremo collection) to understand the effect of water stress on the dynamics of plant biomass and secondary metabolites production, and the morphological and physiological mechanisms involved in plant responses. H. petiolare was cultivated for 34 days under three water regimes: 100% of container capacity (CC, control), 50% CC (moderate water stress), and 0% CC (severe water stress). Plant growth traits, leaf water potential, gas exchange parameters, phenol, flavonoid, and anthocyanin content, and antioxidant activity changes were determined twice a week, while the volatile organic compounds (VOCs) and essential oils (Eos) at the end of the trial. Severe water stress dramatically reduced aerial and root dry weight, chlorophyll and carotenoid content, leaf water potential, water use efficiency (WUE, A/E), transpiration rate (E), stomatal conductance (gs), net photosynthetic rate (A) and antioxidant activity. Moderate water stress induced only slight changes and led to an increase of WUE at the end of the experiment. The total amount of VOCs and Eos was not affected by water stress while their quality changed. Moderate water stress increased the main constituents of both VOCs, i.e. the monoterpene hydrocarbons, and Eos, i.e., the oxygenated sesquiterpenes. In conclusion, this H. petiolare cultivation under the applied moderate drought condition could lead to a double benefit i.e., water-saving irrigation practice and high quality metabolite producti
Effects of the Fractionation of the Nitrogen Fertilization on Root Nitrate Uptake and Vine Agronomic Performance in Pinot Gris Grapevines in a Temperate Climate
Full text linkThe study aims to investigate at a physiological and molecular level the root absorption of nitrogen (N) during the annual cycle of grapevine. The study was performed on potted Pinot Gris plants grafted on Kober 5BB and grown for two consecutive years in a semi-controlled environment (Northeast, Italy). The study compared the response of plants N-fertilized in spring (T1), or in spring and in post-harvest (T2) or no-N fertilized (C). Results showed that under our climate conditions nitrate was taken up by the grapevines when applied both in spring or in spring and post-harvest. The nitrate acquisition in T1 roots is mediated at molecular and physiological level by a higher activation of high-affinity nitrate-transport system to take up nitrate in comparison to no-fertilized plants. Comparing the two N fertilization managements, the dynamic of nitrate uptake rates showed different patterns with an overall late response of High-Affinity Transport System when the application of part of N-fertilization was delayed to post-harvest (T2) in comparison to T1. Nevertheless, during the 2 years of the trial the fractionation of N fertilization applied in spring and post-harvest did not negatively affect the yield and quality parameters of vines. An increase of N concentration in T2 roots after two consecutive growing seasons may suggest that the fractionation can lead to beneficial effects on long period. Results of this work contribute to improve the comprehension of N acquisition in grapevine in order to optimize the use of N inputs in vineyard
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Breeding toward improved ecological plant–microbiome interactions
No full textDomestication processes, amplified by breeding programs, have allowed the selection of more productive genotypes and more suitable crop lines capable of coping with the changing climate. Notwithstanding these advancements, the impact of plant breeding on the ecology of plant–microbiome interactions has not been adequately considered yet. This includes the possible exploitation of beneficial plant–microbe interactions to develop crops with improved performance and better adaptability to any environmental scenario. Here we discuss the exploitation of customized synthetic microbial communities in agricultural systems to develop more sustainable breeding strategies based on the implementation of multiple interactions between plants and their beneficial associated microorganisms
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