Open Access
Deciphering plant health status: the link between secondary metabolites, fungal community and disease incidence in olive tree
(Frontiers Media, 2023) Gomes, Teresa; Pereira, José Alberto; Moya-Laraño, Jordi; Poveda Arias, Jorge; Lino-Neto, Teresa; Baptista, Paula; Institute for Multidisciplinary Research in Applied Biology - IMAB; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
Plant-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 ¿-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.
Open Access
Agronomic and metabolomic side-effects of a divergent selection for indol-3-ylmethylglucosinolate content in kale (Brassica oleracea var. acephala)
(MDPI, 2021) Poveda Arias, Jorge; Velasco, Pablo; Haro, Antonio de; Johansen, Tor J.; McAlvay, Alex C.; Möllers, Christian; Mølmann, Jorgen A.B.; Ordiales, Elena; Rodríguez, Víctor Manuel; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura
Brassica oleracea var. acephala (kale) is a cruciferous vegetable widely cultivated for its leaves and flower buds in Europe and a food of global interest as a 'superfood'. Brassica crops accumulate phytochemicals called glucosinolates (GSLs) which play an important role in plant defense against biotic stresses. Studies carried out to date suggest that GSLs may have a role in the adaptation of plants to different environments, but direct evidence is lacking. We grew two kale populations divergently selected for high and low indol-3-ylmethylGSL (IM) content (H-IM and L-IM, respectively) in different environments and analyzed agronomic parameters, GSL profiles and metabolomic profile. We found a significant increase in fresh and dry foliar weight in H-IM kale populations compared to L-IM in addition to a greater accumulation of total GSLs, indole GSLs and, specifically, IM and 1-methoxyindol-3-ylmethylGSL (1MeOIM). Metabolomic analysis revealed a significant different concentration of 44 metabolites in H-IM kale populations compared to L-IM. According to tentative peak identification from MS interpretation, 80% were phenolics, including flavonoids (kaempferol, quercetin and anthocyanin derivates, including acyl flavonoids), chlorogenic acids (esters of hydroxycinnamic acids and quinic acid), hydroxycinnamic acids (ferulic acid and p-coumaric acid) and coumarins. H-IM kale populations could be more tolerant to diverse environmental conditions, possibly due to GSLs and the associated metabolites with predicted antioxidant potential.
Open Access
Glucosinolates as an effective tool in plant-parasitic nematodes control: exploiting natural plant defenses
(Elsevier, 2022) Eugui Arrizabalaga, Daniel; Escobar, Carolina; Velasco, Pablo; Poveda Arias, Jorge; Agronomia, Bioteknologia eta Elikadura; Institute for Multidisciplinary Research in Applied Biology - IMAB; Agronomía, Biotecnología y Alimentación
Plant-parasitic nematodes (PPNs) are an important damaging biotic agent for numerous crops around the world, causing serious losses directly and indirectly. Cultural and chemical control strategies were mainly used to PPNs management. However, the choice of chemical nematicides is strictly limited in the agrosystems due to their toxicity, their impact to the environment and, therefore, banning policies. The main lines of action of biological control strategies for nematode control, are based on the development of antagonist microorganism formulations and the use of plant extracts with nematicidal potential. There are many plant secondary metabolites with effective nematicidal potential. In this sense, glucosinolates (GSLs) and, especially, glucosinolate hydrolysis products (GHPs) show relevant nematicidal activity. The effects through which these compounds control nematodes, both direct and indirect are diverse, such as toxicity, anti-hatching effect or promotion of competing saprophytic nematodes or nematophagous bacteria populations. The present work compiles many of the studies that describe the use of GSLs and GHPs as nematicides in agriculture, through very diverse strategies that range from crop rotation with Brassicales to the direct application of GSLs and GHPs to the soil. The authors present GSLs and GHPs as a more sustainable and suitable alternative in nematode control, remarking the need to further research in the modes of action and the impact on environment.
Open Access
Editorial: Beneficial effects of fungal endophytes in major agricultural crops
(Frontiers Media, 2022) Poveda Arias, Jorge; Baptista, Paula; Sacristán, Soledad; Velasco, Pablo; Institute for Multidisciplinary Research in Applied Biology - IMAB
Endophytic 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.
Open Access
Control of postharvest diseases in berries through edible coatings and bacterial probiotics
(Elsevier, 2022) Romero, Janira; Albertos, Irene; Díez Méndez, Alexandra; Poveda Arias, Jorge; Institute for Multidisciplinary Research in Applied Biology - IMAB; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
The 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.
Open Access
Combined use of Trichoderma and beneficial bacteria (mainly Bacillus and Pseudomonas): development of microbial synergistic bio-inoculants in sustainable agriculture
(Elsevier, 2022) Poveda Arias, Jorge; Eugui Arrizabalaga, Daniel; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura
Agriculture nowadays is facing many challenges, with among the most important to be able to feed the increasing human population through more sustainable and environmentally friendly production. In this context, the use of microorganisms has been extensively studied, both with fungi such as Trichoderma spp. and with bacteria, such as Bacillus spp. or Pseudomonas spp. While inoculation with these microorganisms has a positive effect on crops, their combination offers even greater potential as plant growth promoters and as biocontrol agents, with diverse mechanisms that are thoroughly considered in this review. Synergies between Trichoderma and bacteria cause more benefits than the sum of their parts, and this makes them a promising alternative for managing crops and controlling diseases or pests in modern agriculture. However, more studies are needed to determine the specific mechanisms of this synergistic effect in certain lines of research, since there is extensive data about their use as plant growth promoters or biocontrol agents against diseases and certain pests, but little or no information is available about their use against diseases caused by viruses or the effect on plant tolerance to abiotic stresses.
Open Access
Broccoli (Brassica oleracea var. italica) biomass as a resource for obtaining glucosinolate extracts to control postharvest fungal diseases
(Springer, 2025-05-27) Eugui Arrizabalaga, Daniel; Fernández San Millán, Alicia; Velasco, Pablo; Veramendi Charola, Jon; Rodríguez, Víctor Manuel; Poveda Arias, Jorge; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura; Institute for Multidisciplinary Research in Applied Biology - IMAB
Broccoli (Brassica oleracea var. italica) is a crop of great agronomic and economic importance worldwide. Because its edible parts are the inflorescences, large quantities of non-commercial biomass are produced each year in the field and in the food industry. In order to develop a circular economy around the broccoli crop, the present work develops glucosinolates (GSL) extracts with antimicrobial capacity for postharvest use in tomato, apple and table white grape against fungal diseases produced by the pathogens Botrytis cinerea, Alternaria alternata and Penicillium expansum. GSL extracts from organic crop management reported a higher content of GSLs than conventional management. These extracts are not effective in the control of A. alternata and P. expansum, possibly due to the absence of sinigrin. Furthermore, the extracts were ineffective in the control of B. cinerea on table white grapes, possibly due to the non-climacteric fruit condition and an absence in the induction of ethylene-mediated plant defenses. However, intact GSL extracts were effective in controlling B. cinerea on apple, while the addition of myrosinase enzyme caused effectiveness also on tomato and apple. Therefore, obtaining GSL extracts with biopesticidal capacity against B. cinerea in postharvest could be a circular economy strategy for broccoli agriculture and industry.
Open Access
Effect of volatile and non-volatile metabolites from Leptosphaeria maculans on tomato calli under abiotic stresses
(Global Science Books, 2022) Poveda Arias, Jorge; Institute for Multidisciplinary Research in Applied Biology - IMAB
Drought and salinity can be serious problems for agricultural productivity in certain planet areas. Leptosphaeria maculans is the causative agent of the blackleg in crucifer plants. In this work, a novel methodology for studying the effects of fungal metabolites (volatile and non-volatile) on plant calli in the presence of abiotic stresses is presented, by using L. maculans, tomato calli, and drought and salinity stresses. In this way, this study has reported how, under salinity and drought stresses, the growth and vitality of tomato calli is inhibited, increasing its tissues-oxidation and accumulation of ROS. By applying metabolites from L. maculans, the growth of calli treated with non-volatile metabolites showed and increment under salinity and drought conditions. On the other hand, calli treated with volatile metabolites showed an increment in tissues-vitality under salinity and drought conditions. A series of gene expression analysis was also conducted in order to determine the performance of related genes. Results of this study showed that growth related gene expression was induced, together with abiotic stress tolerance gene in response to abscisic acid, AREB1. In addition, the application of volatile metabolites from L. maculans on tomato calli without abiotic stresses increases its growth and vitality, and reduces its oxidation and accumulation of ROS, in accordance with the results of gene expression obtained. The ability of L. maculans metabolites to increase plant tolerance to abiotic stresses could be related to their ability to produce volatile and non-volatile-metabolites, which induce the antioxidant enzyme activity or accumulation of antioxidant compounds, or their ability to increase the expression of ABA-dependent response genes to abiotic stresses.
Open Access
Microorganisms as biocontrol agents against bacterial citrus diseases
(Elsevier, 2021) Poveda Arias, Jorge; Roeschlin, Roxana Andrea; Marano, María Rosa; Favaro, María Alejandra; Institute for Multidisciplinary Research in Applied Biology - IMAB
Citrus represents one of the most widely grown crops on the planet, extensively cultivated for both the fresh fruit and juice markets. The productivity of citrus orchards can be seriously affected by highly aggressive pathogenic bacteria, such as Xanthomonas citri subsp. citri, Xylella fastidiosa subsp. pauca and currently Candidatus Liberibacter asiaticus. Different microbiological biocontrol agents have been described against these pathogens, such as antagonistic bacteria (mainly species from Pseudomonas and Bacillus genus) and bacteriophages. This review summarizes all the microbiological control strategies reported so far against bacterial diseases that affect citrus, highlighting those fields of study where there is great potential yet to be discovered.
Open Access
Filamentous fungi as biocontrol agents in olive (Olea europaea L.) diseases: mycorrhizal and endophytic fungi
(Elsevier, 2021) Poveda Arias, Jorge; Baptista, Paula; Institute for Multidisciplinary Research in Applied Biology - IMAB
Olive (Olea europaea) is a crop of great agronomic, economic and cultural interest for the Mediterranean Basin, although the increase in world demand for olive oil is expanding its cultivation by other countries in the southern hemisphere. The main olive pathogens include bacteria (Pseudomonas savastanoi pv. savastanoi, Xylella fastidiosa), fungi (Colletotrichum spp., Verticillium dahliae, Fusarium spp. Rhizoctonia solani), oomycetes (Phytophthora spp.) and nematodes (Meloidogyne spp.). To combat these pathogens, different biocontrol strategies have been developed with bacteria and yeasts, although its capacity for establishment in the field entails several difficulties. In this sense, filamentous fungi represent an efficient and effective alternative in the control of the different pathogens of the olive tree. The present review compiles all the studies existing so far in the biocontrol of these pathogens through the use of mycorrhizal and endophytic filamentous fungi, making a separate section for the genus Trichoderma due to the special interest that their use has generated. The mechanisms used by these fungi include competition for space and nutrients, parasitism, antibiosis or activation of the plant's defensive responses, among others.