Browsing by Author "Poveda, Jorge"
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- Control of postharvest diseases in berries through edible coatings and bacterial probioticsPublication . Romero, Janira; Albertos, Irene; Díez-Méndez, Alexandra; Poveda, JorgeThe world’s population is growing, which requires more resources, including food. Some necessary foods, such as berries, are very perishable fresh products that suffer contamination by pathogens, generating great economic losses. Various physical and chemical strategies have been used to mitigate these losses over the years, including the use of pesticides. However, the negative impact on the environment and human health of these chemical products has aroused interest in the development of other control methods. Biocontrol is one of these innovative strategies, in which various biological control agents can be used, including bacteria probiotics. Probiotics act as antagonists of fungal pathogens by competition for space and nutrients, production of secondary metabolites, such as volatile organic compounds (VOCs), lytic enzymes, and activation of plant defenses. On the other hand, there are materials in which protection against pathogens has been seen, such as edible coatings, since they have components, such as chitosan, with antimicrobial properties. In addition, probiotics can be used in conjunction with other elements such as edible coatings, resulting from a new control strategy against post-harvest diseases. This review compiles studies that use probiotics and/or edible coatings as a method of reducing post-harvest diseases, specifically, in berries.
- Deciphering plant health status: the link between secondary metabolites, fungal community and disease incidence in olive treePublication . Gomes, Teresa; Pereira, J.A.; Moya-Larano, Jordi; Poveda, Jorge; Lino-Neto, Teresa; Baptista, PaulaPlant-associated microorganisms are increasingly recognized to play key roles in host health. Among several strategies, associated microorganisms can promote the production of specific metabolites by their hosts. However, there is still a huge gap in the understanding of such mechanisms in plant-microorganism interaction. Here, we want to determine whether different levels of olive leaf spot (OLS) disease incidence were related to differences in the composition of fungal and secondary metabolites (i.e. phenolic and volatile compounds) in leaves from olive tree cultivars with contrasting OLS susceptibilities (ranging from tolerant to highly susceptible). Accordingly, leaves with three levels of OLS incidence from both cultivars were used to assess epiphytic and endophytic fungal communities, by barcoding of cultivable isolates, as well as to evaluate leaf phenolic and volatile composition. Fungal and metabolite compositions variations were detected according to the level of disease incidence. Changes were particularly noticed for OLS-tolerant cultivars, opposing to OLS-susceptible cultivars, suggesting that disease development is linked, not only to leaf fungal and metabolite composition, but also to host genotype. A set of metabolites/fungi that can act as predictive biomarkers of plant tolerance/susceptibility to OLS disease were identified. The metabolites alpha-farnesene and p-cymene, and the fungi Fusarium sp. and Alternaria sp. were more related to disease incidence, while Pyronema domesticum was related to the absence of disease symptoms. Cultivar susceptibility to OLS disease is then suggested to be driven by fungi, volatile and phenolic host leaves composition, and above all to plant-fungus interaction. A deeper understanding of these complex interactions may unravel plant defensive responses.
- Editorial: Beneficial effects of fungal endophytes in major agricultural cropsPublication . Poveda, Jorge; Baptista, Paula; Sacristan, Soledad; Velasco, PabloEndophytic microorganisms are those that can dwell within plant tissues without any external sign of infection or other harmful effects on the host plants (Burragoni and Jeon, 2021). In recent decades, the important role that both bacterial and fungal endophytes play in plant growth and development, as well as in their ability to survive in their environment, has been identified (Burragoni and Jeon, 2021). Endophytic fungi can be found colonizing any plant organ, presenting a very different distribution and diversity among plants of different species, among plants of the same species, and even among organs of the same plant (Aamir et al., 2020). In crops, endophytic fungi act through different beneficial pathways, as biofertilizers promoting plant growth, as biological control agents of pathogens and pests or as inducers of tolerance under abiotic stresses, having great importance in the development of new strategies for sustainable agriculture (Aamir et al., 2020). These benefits for crops have been studied in the papers published in this Research Topic: promotion of plant growth in tomato (Paradza et al.), cotton (Silva et al.) and wheat (Asim et al.), increased tolerance under salt stress in tritordeum and perennial ryegrass (Toghueo et al.), as biological control agents against pathogenic fungi through antibiosis and mycoparasitism (Silva et al.), or as insecticidal agents through activation of systemic plant defenses (Paradza et al.; Agbessenou et al.), among others.
- First study on the root endophytic fungus Trichoderma hamatum as an entomopathogen: development of a fungal bioinsecticide against cotton leafworm (Spodoptera littoralis)Publication . Lana, Maite; Simo, Oihane; Velasco, Pablo; Rodriguez, Victor M.; Caballero, Primitivo; Poveda, JorgeCotton leaf worm (Spodoptera littoralis) is a pest that produces important losses in horticultural and ornamental crops in greenhouse, being classified as quarantine pest A2 by EPPO. One of the strategies proposed to control agricultural pests in a health and environmentally friendly way is biological control with entomopathogenic fungi. The genus of filamentous fungi Trichoderma includes different species with direct (infection, antibiosis, anti-feeding, etc.) and indirect (systemic activation of plant defenses) insecticidal capacity, however, the species T. hamatum has never been described previously as entomopathogenic. In this work, the entomopathogenic capacity of T. hamatum on S. littoralis L3 larvae was analyzed by applying spores and fungal filtrates (topically and orally). Infection by spores was compared with the commercial entomopathogenic fungus Beauveria bassiana, obtaining similar results with respect to the production of larval mortality. Oral application of spores reported high mortality and fungal colonization of larvae, however, T. hamatum did not show chitinase activity when grown in the presence of S. littoralis tissues. Therefore, infection of S. littoralis larvae by T. hamatum is through natural openings such as mouth, anus or spiracles. With respect to the application of filtrates, only those obtained from the liquid culture of T. hamatum in contact with S. littoralis tissues reported a significant reduction in larval growth. Metabolomic analysis of the filtrates determined that the filtrate with insecticidal capacity presented the siderophore rhizoferrin in large quantities, which could be responsible for this activity. However, the production of this siderophore had never been previously described in Trichoderma and its insecticidal capacity was unknown. In conclusion, T. hamatum presents entomopathogenic capacity against S. littoralis larvae through the application of spores and filtrates, and both ways could be the basis for the development of efficient bioinsecticides against the pest.
- The use of freshwater macrophytes as a resource in sustainable agriculturePublication . Poveda, JorgeFreshwater macrophytes include different groups of plants that are capable of growing in or very close to aquatic environments (spermatophytes, pteridophytes and bryophytes). These plants play a fundamental role in their ecosystems, regulating biogeochemical cycles, hydrology and sediment dynamic. Currently, many exotic freshwater macrophytes are being anthropogenically introduced into new ecosystems, posing a serious problem as a consequence of their massive and uncontrolled growth. Despite this, these plants can have different uses, such as biomarkers, phytoremediators, producers of metabolites of interest, or biomass formers for the production of feed, biofuels, pellets or ceramics. In this sense, the use of freshwater macrophytes in vivo, as fresh tissues, dry matter, compost, vermicompost, anaerobic digestate, liquid extracts or biochar has reported important benefits in different crops, promoting plant growth, increasing yield, reducing use of chemical fertilizers or reducing the diseases incidence. These benefits are the consequence of different mechanisms of action of the use of macrophytes as an agricultural resource, such as the contribution of nutrients, the improvement of the microbiota and soil structure, the elimination of heavy metals and pollutants, or the presence of antimicrobial compounds in their tissues. This review proposes the use of the biomass of these macrophytes, whose uncontrolled growth is an environmental problem, as an agricultural resource with important agricultural, environmental and economic benefits. A total of 118 published papers were analyzed and discussed.
- Use of elicitors from macroalgae and microalgae in the management of pests and diseases in agriculturePublication . Poveda, Jorge; Díez-Méndez, AlexandraFeeding a growing population is a big challenge for agriculture, being necessary for new and ecological alternatives to reduce chemical fertilizers and pesticides. Scientists have found that microand macroalgae are essential reservoirs of chemical compounds with a high potential role as biopesticides. Some of these molecules can act as elicitors, activating systemic and local defensive responses even without biotic stress. Among elicitors from macroalgae, there are ulvans, laminarin, alginate, carrageenan, glucuronan, fucans and tannins, which can activate plant defenses against viruses, bacteria, fungi, oomycetes, nematodes, and insects. The induction of defense mechanisms on crops by microalgae is related to their application as biomass, polysaccharides, exopolysaccharide or other elicitors, such as lactic acid or glucosamine. Unlike macroalgae, the biopesticide effect by microalgae has only been described against bacteria, fungi, and oomycetes, being necessary more studies to elucidate and discover their role as elicitors. In general, both macroand microalgae are sources of compounds with great potential as biopesticides following the current needs for the development of sustainable agriculture.