Mass spectrometry based proteomics for the molecular fingerprinting of Fiano, Greco and Falanghina cultivars

Abstract The official methodologies used for the identification and comparison of vine cultivars are ampelography and ampelometry. These methodologies are essentially based on qualitative assessments or biometric dependent morphological features of the plant. The heterogeneity of cultivars and consequently the increasing demand for a more detailed product typization, led to the introduction of new methodologies for the varietal characterization. In this scenario, proteomics has already proved to be a very useful discipline for the typization of many kinds of edible products. In this paper, we present a proteomic study carried out on three cultivars of Vitis vinifera peculiar of south Italy (Campania) used for white wine production (Fiano, Greco and Falanghina) by advanced biomolecular mass spectrometry approach. Our data highlight variations in the proteomic profiles during ripening for each cultivar and between analyzed cultivars, thus suggesting a new way to outline the biomolecular signature of vines

Metabolomics for the selection of beneficial microorganisms and/or their functional metabolites for agricultural uses

Novel eco-sustainable approaches employed for plant protection and growth promotion involve the use of microbial inoculants. Beneficial microbes play also an important role as primary source of secondary metabolites for drug discovery and application in both medical and agricultural fields. Omics studies can help to understand the mechanisms of microbial interactions and can guide the selection of active principles (microbes and/or bioactive metabolites) for new bio-formulates. A metabolomic approach has been used to investigate the compatibility of different beneficial strains (i.e., Trichoderma, Streptomyces, Azotobacter). Therefore the selected combinations have been tested on different crops of agricultural importance (parsley, basil, olive drupes), in order to evaluate the effect of these combinations on yield, growth, pathogens biocontrol and nutritional value. Moreover, the metal chelating properties of harzianic acid (a known Trichoderma bioactive compound) have been evaluated in order to discover new possible applications in soil remediation and/or as biostimulant

Metabolic Profile and Mycoherbicidal Activity of Three Alternaria alternata Isolates for the Control of Convolvulus arvensis, Sonchus oleraceus, and Xanthium strumarium

: Alternaria alternata isolates C1, S1, and X3 were isolated respectively from the weeds Convolvulus arvensis, Sonchus oleraceus, and Xanthium strumarium in Algiers during 2016 and identified by morphological and molecular analyses. The aim of this investigation was to chemically characterize the exometabolome of these fungi and to evaluate the myco-herbicidal potential of their culture filtrates, crude extracts, or fractions towards target weeds. Results revealed a great heterogeneity in the biochemical profiles of the exometabolome with the remarkable presence of two compounds: tenuazonic acid (TeA) and triprenyl phenol-7 (SMTP-7). To the best of our knowledge, SMTP-7-found in all the isolates-as well as 12-methoxycitromycin detected in the culture filtrate of isolate C1, have never been reported to be produced by A. alternata. Some fractions of isolates C1 and S1 showed symptoms (necrosis and chlorosis) on the detached leaves of C. arvensis and S. oleraceus, respectively with up to 100% phytotoxic effect at low concentration. In conclusion, biochemical characterization revealed great difference of C1, S1, and X3 exometabolome that is likely to explain the difference in their phytotoxic activity. Some fractions (d1, e1, h1, i1, a2, and f2) of isolates C1 and S1 of A. alternata caused severe necrosis and chlorosis on the injured detached leaves of C. arvensis and S. oleraceus, respectively

Interactions between plant‐beneficial microorganisms in a consortium: Streptomyces microflavus and Trichoderma harzianum

The construction of microbial consortia is challenging due to many variables to be controlled, including the cross-compatibility of the selected strains and their additive or synergistic effects on plants. In this work, we investigated the interactions in vitro, in planta, and at the molecular level of two elite biological control agents (BCAs), that is Streptomyces microflavus strain AtB-42 and Trichoderma harzianum strain M10, to understand their attitude to cooperate in a consortium. In vitro, we observed a strong cross-antagonism between AtB-42 and M10 in agar plates due to diffusible metabolites and volatile organic compounds. In liquid co-cultures, M10 hindered the growth of AtB-42 very likely because of secondary metabolites and strong competition for the nutrients. The interaction in the co-culture induced extensive transcriptional reprogramming in both strains, especially in the pathways related to ribosomes, protein synthesis, and oxidoreductase activity, suggesting that each strain recognized the counterpart and activated its defence responses. The metabolome of both strains was also significantly affected. In contrast, in the soil, M10 growth was partially contrasted by AtB-42. The roots of tomato seedlings inoculated with the consortium appeared smaller than the control and single-strain-inoculated plants, indicating that plants diverted some energy from the development to defence activation, as evidenced by the leaf transcriptome. The consortium induced a stronger transcriptional change compared to the single inoculants, as demonstrated by a higher number of differentially expressed genes. Although the cross-antagonism observed in vitro, the two strains exerted a synergistic effect on tomato seedlings by inducing resistance responses stronger than the single inoculants. Our observations pose a question on the usefulness of the sole in vitro assays for selecting BCAs to construct a consortium. In vivo experiments should be preferred, and transcriptomics may greatly help to elucidate the activity of the BCAs beyond the phenotypic effects on the plant

Biological activities of Viscum tuberculatum aqueous leaf extract

ABSTRACT Content: Plant-based natural products have served as sources of remedies against pathogenic microorganisms. Although the biological activities of Viscum (Santalaceae) species are widely recognized, there is no scientific evidence for Viscum tuberculatum A. Rich. in Ethiopia. Objective: To investigate the antimicrobial, acute toxicity, anti-inflammatory properties and phytochemical constituents of an aqueous extract of V. tuberculatum from Ethiopia. Materials and methods: The antibacterial activity of the aqueous leaf extract of V. tuberculatum was tested against Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of this extract were determined using the broth macrodilution method. The acute toxicity and anti-inflammatory effects of the extract were investigated using standard procedures on female and male white albino mice, aged 8 and 10 weeks, respectively. The phytochemical constituents of V. tuberculatum were determined using LC–MS QTOF. Results: The MIC and MBC values against S. aureus were found to be 6.25 and 100mg/mL. The LD50 value was more than 2000mg/kg body weight of the mouse. The 400mg/kg dose exerts 87% inhibition after 5 h of carrageenan injection. Twenty-five different metabolites, mainly flavonoids, phenolic acids and alkaloids, were identified. Conclusions: These findings demonstrate the potential antimicrobial and anti-inflammatory potential of the aqueous extract of V. tuberculatum

Biological and phytochemical characterization of Phragmanthera regularis (Loranthaceae) from Ethiopia

Phragmanthera regularis is a hemi-parasitic shrub. It is known for treating various health ailments. The aim of this study was to evaluate the antimicrobial activity, toxicity, and chemical characterization of the leaf extracts of P regularis collected from the Schinus molle host plant in Ethiopia. The antimicrobial properties of crude extracts obtained with chloroform, ethyl acetate, methanol, and water solvents were assayed against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. The methanol extract significantly inhibited the growth of S. aureus, E. coli and P. aeruginosa were resistant to any of these solvent extracts. The methanol extract was tested at 175, 550, and 2000 mg/kg body weight doses in white mice and did not reveal any toxicity. The LC-MS qTOF analysis detected flavonoids, phenolic acids, and alkaloids in the crude methanol extract. Further study is needed to investigate the effectiveness of these compounds against S. aureus

Increased water use efficiency in miR396-downregulated tomato plants

MicroRNAs regulate plant development and responses to biotic and abiotic stresses but their impact on water use efficiency (WUE) is poorly known. Increasing WUE is a major task in crop improvement programs aimed to meet the challenges posed by the reduction in water availability associated with the ongoing climatic change. We have examined the physiological and molecular response to water stress of tomato (Solanum lycopersicum L.) plants downregulated for miR396 by target mimicry. In water stress conditions, miR396-downregulated plants displayed reduced transpiration and a less then proportional decrease in the photosynthetic rate that resulted in higher WUE. The increase in WUE was associated with faster foliar accumulation of abscisic acid (ABA), with the induction of several drought-protective genes and with the activation of the jasmonic acid (JA) and γ-aminobutyric acid (GABA) pathways. We propose a model in which the downregulation of miR396 leads to the activation of a complex molecular response to water stress. This response acts synergistically with a set of leaf morphological modifications to increase stomatal closure and preserve the efficiency of the photosynthetic activity, ultimately resulting in higher WUE

The Shifting Mycotoxin Profiles of Endophytic Fusarium Strains: A Case Study

Fusarium species are known to establish manifold interactions with wild and crop plants ranging from pathogenicity to endophytism. One of the key factors involved in the regulation of such relationships is represented by the production of secondary metabolites. These include several mycotoxins, which can accumulate in foodstuffs causing severe health problems to humans and animals. In the present study, an endophytic isolate (A1021B), preliminarily ascribed to the Fusarium incarnatum-equiseti species complex (FIESC), was subjected to biochemical and molecular characterization. The metabolomic analysis of axenic cultures of A1021B detected up to 206 compounds, whose production was significantly affected by the medium composition. Among the most representative products, fusaric acid (FA), its derivatives fusarinol and 9,10-dehydro-FA, culmorin and bikaverin were detected. These results were in contrast with previous assessments reporting FIESC members as trichothecene rather than FA producers. However, molecular analysis provided a conclusive indication that A1021B actually belongs to the species Fusarium babinda. These findings highlight the importance of phylogenetic analyses of Fusarium species to avoid misleading identifications, and the opportunity to extend databases with the outcome of metabolomic investigations of strains from natural contexts. The possible contribution of endophytic strains in the differentiation of lineages with an uneven mycotoxin assortment is discussed in view of its ensuing impact on crop productions