Plant Health Research Articles

One stone two birds: Endophytes alleviating trace elements accumulation and suppressing soilborne pathogen by stimulating plant growth, photosynthetic potential and defense related gene expression

In the present investigation, we utilized zinc nanoparticles (Zn-NPs) and bacterial endophytes to address the dual challenge of heavy metal (HM) toxicity in soil and Rhizoctonia solani causing root rot disease of tomato. The biocontrol potential of Bacillus subtilis and Bacillus amyloliquefaciens was harnessed, resulting in profound inhibition of R. solani mycelial growth and efficient detoxification of HM through strong production of various hydrolytic enzymes and metabolites. Surprisingly, Zn-NPs exhibited notable efficacy in suppressing mycelial growth and enhancing the seed germination (%) while Gas chromatography-mass spectrometry (GC-MS) analysis unveiled key volatile compounds (VOCs) crucial for the inhibition of pathogen. Greenhouse trials underscored significant reduction in the disease severity (%) and augmented biomass in biocontrol-mediated plants by improving photosynthesis-related attributes. Interestingly, Zn-NPs and biocontrol treatments enhanced the antioxidant enzymes and mitigate oxidative stress indicator by increasing H2O2 concentration. Field experiments corroborated these findings, with biocontrol-treated plants, particularly those receiving consortia-mediated treatments, displayed significant reduction in disease severity (%) and enhanced the fruit yield under field conditions. Root analysis confirmed the effective detoxification of HM, highlighting the eco-friendly potential of these endophytes and Zn-NPs as fungicide alternative for sustainable production that foster soil structure, biodiversity and promote plant health.

Root endophytic bacterial communities are shaped by the specific microbiota associated to mycorrhizal symbionts

Abstract Background and aims Arbuscular mycorrhizal fungi (AMF) are beneficial soil microorganisms establishing mutualistic symbioses with most crop plants and promoting plant growth and health. AMF beneficial activities are complemented by their associated microbiota, leading to synergistic interactions positively affecting plant performance. In this work we assessed whether AMF may act as drivers of root bacterial endophytes, facilitating root colonization of host plants by their associated bacteria. Methods Two AMF isolates were used, Funneliformis mosseae from Indiana (USA) and Septoglomus sp. from Tuscany (Italy) in an original experimental microcosm system, utilizing micropropagated plants of Prunus persica x Prunus amygdalus inoculated with either intact or mechanically crushed AMF spores, the former able and the latter unable to establish the symbiosis. Spore and root endophytic bacterial communities diversity were analysed by Illumina Miseq sequencing. Results This study revealed that AMF with their associated bacteria can shape the root endophytic bacterial communities, inducing differential recruitment depending on the composition of spore-associated microbiota. Such data were consistent between two AMF isolates, associated with diverse bacterial communities, as shown by PERMANOVA, Bray Curtis dissimilarity, hierarchical clustering and indicator species analyses. Moreover, specific bacterial taxa were found exclusively in mycorrhizal roots. Our findings suggested also a differential recruitment depending on the ability of AMF to establish mycorrhizal symbioses. Conclusion This work revealed that AMF represent drivers of the endophytic bacterial communities diversity and composition, facilitating root colonization of host plants by their associated bacteria, that become an integral part of the root microbiome as endophytes.

Smartphone-Based Citizen Science Tool for Plant Disease and Insect Pest Detection Using Artificial Intelligence

In recent years, the integration of smartphone technology with novel sensing technologies, Artificial Intelligence (AI), and Deep Learning (DL) algorithms has revolutionized crop pest and disease surveillance. Efficient and accurate diagnosis is crucial to mitigate substantial economic losses in agriculture caused by diseases and pests. An innovative Apple® and Android™ mobile application for citizen science has been developed, to enable real-time detection and identification of plant leaf diseases and pests, minimizing their impact on horticulture, viticulture, and olive cultivation. Leveraging DL algorithms, this application facilitates efficient data collection on crop pests and diseases, supporting crop yield protection and cost reduction in alignment with the Green Deal goal for 2030 by reducing pesticide use. The proposed citizen science tool involves all Farm to Fork stakeholders and farm citizens in minimizing damage to plant health by insect and fungal diseases. It utilizes comprehensive datasets, including images of various diseases and insects, within a robust Decision Support System (DSS) where DL models operate. The DSS connects directly with users, allowing them to upload crop pest data via the mobile application, providing data-driven support and information. The application stands out for its scalability and interoperability, enabling the continuous integration of new data to enhance its capabilities. It supports AI-based imaging analysis of quarantine pests, invasive alien species, and emerging and native pests, thereby aiding post-border surveillance programs. The mobile application, developed using a Python-based REST API, PostgreSQL, and Keycloak, has been field-tested, demonstrating its effectiveness in real-world agriculture scenarios, such as detecting Tuta absoluta (Meyrick) infestation in tomato cultivations. The outcomes of this study in T. absoluta detection serve as a showcase scenario for the proposed citizen science tool’s applicability and usability, demonstrating a 70.2% accuracy (mAP50) utilizing advanced DL models. Notably, during field testing, the model achieved detection confidence levels of up to 87%, enhancing pest management practices.

Zno nanoparticles: improving photosynthesis, shoot development, and phyllosphere microbiome composition in tea plants

BackgroundNanotechnology holds revolutionary potential in the field of agriculture, with zinc oxide nanoparticles (ZnO NPs) demonstrating advantages in promoting crop growth. Enhanced photosynthetic efficiency is closely linked to improved vigor and superior quality in tea plants, complemented by the beneficial role of phyllosphere microorganisms in maintaining plant health. However, the effects of ZnO NPs on the photosynthesis of tea plants, the sprouting of new shoots, and the community of phyllosphere microorganisms have not been fully investigated.ResultsThis study investigated the photosynthetic physiological parameters of tea plants under the influence of ZnO NPs, the content of key photosynthetic enzymes such as RubisCO, chlorophyll content, chlorophyll fluorescence parameters, transcriptomic and extensive targeted metabolomic profiles of leaves and new shoots, mineral element composition in these tissues, and the epiphytic and endophytic microbial communities within the phyllosphere. The results indicated that ZnO NPs could enhance the photosynthesis of tea plants, upregulate the expression of some genes related to photosynthesis, increase the accumulation of photosynthetic products, promote the development of new shoots, and alter the content of various mineral elements in the leaves and new shoots of tea plants. Furthermore, the application of ZnO NPs was observed to favorably influence the microbial community structure within the phyllosphere of tea plants. This shift in microbial community dynamics suggests a potential for ZnO NPs to contribute to plant health and productivity by modulating the phyllosphere microbiome.ConclusionThis study demonstrates that ZnO NPs have a positive impact on the photosynthesis of tea plants, the sprouting of new shoots, and the community of phyllosphere microorganisms, which can improve the growth condition of tea plants. These findings provide new scientific evidence for the application of ZnO NPs in sustainable agricultural development and contribute to advancing research in nanobiotechnology aimed at enhancing crop yield and quality.Graphical

Italian adaptation to Regulation (EU) 2017/625 on food official controls: a case study

Foodborne diseases can be prevented by implementing a food safety system that manages food chain risks from producer to end-user, from a One Health perspective. In 2017, the European Parliament and the European Council adopted Regulation No. 625 on official food controls and other official activities performed to ensure the application of food and feed laws and rules on animal health and welfare, plant health, and plant protection products. Italy issued a national law, Legislative Decree No. 27/2021, to adapt and adhere to European standards. We aim to describe the adoption and implementation of the new Legislative Decree by an Italian Food Hygiene and Nutrition Service, specifically focusing on the amendments introduced by Articles 7 and 8, namely the establishment of the second expert opinion and dispute procedures, and their integration with the promulgation of Article 70 of Legislative Decree No. 150/2022. These modifications aim to reduce the number of minor offenses that proceed to trial.

Role of Bacteria in Plant Nutrient Mobilization: A Review

Plant roots are the site of dynamic and complex interactions between a variety of microorganisms, such as fungi, bacteria, and archaea. Plant Growth-Promoting Rhizobacteria (PGPR) is one of those that are important for improving the health and growth of plants. Bacteria are among the most abundant and diverse microorganisms in the rhizosphere. These bacteria contribute to various processes, including nitrogen fixation, phosphate solubilization, and production of plant growth-promoting substances, thereby enhancing plant nutrient uptake and growth. Fungi are another important component of the rhizosphere microbiota. These microbes are used as bioinoculants in the agricultural field, replacing the traditional use of pesticides. Bioinoculants do not show any detrimental impact on the soil's plant and animal life as they are eco-friendly, highly efficient, and can be utilized as bio-pesticides that do not have any harmful influence on plant products. Understanding the composition and functions of rhizosphere microbiota is crucial for developing sustainable agricultural practices that harness the beneficial interactions between plants and microorganisms to enhance soil fertility and crop productivity while minimizing environmental impacts. This review examines the emerging use of microorganisms in the agricultural field, which can replace the chemical fertilizers that are proven hazardous if used extensively over crops, specifically regarding the important micronutrients required by the plant. The current study addresses the gap in the effectiveness of these microorganisms as bio-inoculants in the rhizosphere and future aspects of the microbes for crop productivity.

PLANT-GROWTH-PROMOTING AND ANTIFUNGAL ASSET OF INDIGENOUS DROUGHT-TOLERANT RHIZOBACTERIA ISOLATED FROM OLIVE (Olea europaea L.) RHIZOSPHERE

Faced with global environmental challenges, the quest for sustainable food production has gathered momentum. While abiotic stresses adversely affect plant health and productivity, Verticillium wilt causes considerable yield losses worldwide, particularly in crops such as olive. Recently, drought-tolerant bacteria have been used to alleviate both abiotic stress and pathogen pressure in crops. In this context, our work focuses on the isolation of tolerant indigenous rhizobacteria to mitigate these challenges by investigating their role in biocontrol and abiotic stress tolerance. Thus, a total of 94 rhizobacterial strains were isolated from the rhizospheres of olive trees in southeastern Morocco and characterized to identify tolerant plant growth-promoting rhizobacteria that inhibit Verticillium dahliae. 24 strains demonstrated in vitro suppression of Verticillium dahliae Klebahn, and exhibited tolerance to different abiotic stresses (drought, salinity, and high temperature). In addition, they proved xerotolerant (Aw ≤ 0.91), halotolerant (≥10% NaCl), and thermotolerant (≥ 55°C) capabilities. Beyond, these isolates showcased multifaceted plant growth-promoting traits, such as phosphate solubilization and significant synthesis of essential bioactive compounds like siderophores, indole-3-acetic acid and hydrolytic enzymes. Evaluating outcomes, three standout rhizobacterial isolates emerged due to their exceptional stress tolerance, unique plant growth-promoting qualities, and potent antagonistic potential. Molecular analysis identified them as Bacillus paranthracis (OZ-60) and Bacillus licheniformis (OZ-48 and OZ-77) through 16S rRNA sequencing. Besides enhancing plant abiotic stress resistance, these isolates hold promise in bolstering the sustainability of olive cultivation and fortifying plant defenses against pathogens.

Potential of Castanea sativa for biomonitoring As, Hg, Pb, and Tl: A focus on their distribution in plant tissues from a former mining district

Bioavailability of potentially toxic elements (PTEs) from the Earth's crust in the soil, e.g., As, Hg, Tl, and Pb, can pose a potential environmental and health risk because of human activities, especially related to mining extraction. The biomonitoring allows to detect PTE contamination through their measurement in living organisms as trees. However, the choice of which plant species and tissue to analyse is a key point to be evaluated in relation to PTE absorption and translocation. The aim of this work was to assess the As, Hg, Tl, and Pb distribution in Castanea sativa Mill. plant tissues, given its importance for both biomass and food production. The study identified two sites in the Alpi Apuane (Italy), with similar environmental conditions (e.g., elevation, exposure, forest type, and tree species) but different soil PTE levels. The topsoil was characterized, and the PTE fractions with different bioavailability were measured. The PTE concentrations were also analysed in chestnut plant tissues (leaves, bark, wood, nuts, and shells) in parallel with and evaluation of plant health status through the determination of micro and macronutrient concentrations and the leaf C and N isotope composition (δ13C or δ15N). Chestnut trees showed a good health status highlighting its suitability for Tl, As, Hg, and Pb biomonitoring, displaying a tissue-specific PTE allocation. Thallium and Hg were detected in all plant tissues at similar concentrations, As was found in leaves, wood, and nuts while Pb only in the bark. The δ15N negatively correlated with leaf Mn and Tl concentrations, suggesting possible changes in N source and/or plant metabolism due to the high contamination level and acid soil pH. Thallium in La Culla site trees was associated with its presence in the carbonate rocks but not in the topsoil, highlighting the potentiality of chestnut in providing valuable information for geochemical surveying.

Commodity risk assessment of Prunus avium plants from United Kingdom.

The European Commission requested the EFSA Panel on Plant Health to prepare and deliver risk assessments for commodities listed in Commission Implementing Regulation (EU) 2018/2019 as 'High risk plants, plant products and other objects'. This Scientific Opinion covers plant health risks posed by plants of Prunus avium possibly grafted on rootstocks of either P. avium, P. canescens, P. cerasus, P. pseudocerasus or their hybrids imported from the UK, taking into account the available scientific information, including the technical information provided by the UK. All pests associated with the commodities were evaluated against specific criteria for their relevance for this opinion. Three quarantine pests Scirtothrips dorsalis, tobacco ringspot virus and tomato ringspot virus), one protected zone EU quarantine pest (Bemisia tabaci (European population), and three non- regulated pests (Colletotrichum aenigma, Eulecanium excrescens and Takahashia japonica) that fulfilled all relevant criteria were selected for further evaluation. The risk mitigation measures proposed in the technical Dossier from the UK were evaluated, taking into account the possible limiting factors. For these pests, expert judgement is given on the likelihood of pest freedom, taking into consideration the risk mitigation measures acting on the pest, including uncertainties associated with the assessment. The degree of pest freedom varies among the pests evaluated, with Colletotrichum aenigma being the pest most frequently expected on the imported potted plants. The Expert Knowledge Elicitation indicated with 95% certainty that between 9971 and 10,000 plants per 10,000 would be free from the above-mentioned fungus.

Assessment of ecological and public health risks associated with heavy metals on farmland in Wonosobo Regency, Indonesia

The deposition of metallic substances on farmland is of critical importance owing to its possible detrimental impacts on the surroundings and human wellness. Heavy metals can adversely affect the physicochemical properties of soil and plant health. Prolonged exposure to heavy metals in humans can lead to both carcinogenic and non-carcinogenic effects. The present research intended to determine the dispersion condition of toxic metals on cropland and assess the attendant environmental and health dangers in the Wonosobo Regency. This study used a soil sample survey encompassing 312 soil sampling sites. The completed analyses comprise geographical analysis, index of geo-accumulation (IG), contamination index (CI), Nemerow comprehensive contamination index (NCCI), risk analysis, and health risk analysis. The research findings reveal that cadmium material is the primary contributor to contamination from heavy metals in farmland in Wonosobo Regency, as shown by IG analysis. The CI and environmental hazards assessments suggest considerable pollution levels. Kids are more prone to illnesses than adults due to their daily intake amount, so it is necessary to pay more attention to the daily intake sources in children to minimize exposure to heavy metals.

The Role of Consumers’ Knowledge of Native and Pollinator-friendly Plants and Their Prioritization of Plant Characteristics in Purchase Decisions

There is a growing trend toward planting native and pollinator-friendly plants in residential gardens and landscapes due to concerns about invasive plant species, water conservation, and urban land management. Yet, understanding consumer purchase behavior and how knowledge affects their purchase intent is largely unknown. In this analysis, we integrated national online and in-person surveys to determine the influence of consumers’ subjective and objective knowledge of native and pollinator-friendly ornamental plants on their purchase decisions. Factors influencing plant purchase decisions were measured using a 7-point Likert rating scale. We found that participants with relatively higher knowledge of native and pollinator-attractive plants placed more emphasis on sustainable production methods relative to the plant’s physical attributes (e.g., plant size, shape, etc.) and care-related characteristics (e.g., plant health, easiness of care, etc.). Plant lovers (i.e., frequent purchasers who spent relatively more money on plants than infrequent purchasers) were more likely to prioritize sustainable production methods over the plants’ physical attributes. In contrast, participants primarily buying plants from mass merchandisers/box stores tend to focus on visual appeal or aesthetic characteristics. Consumer marketing implications for the nursery and greenhouse industry stakeholders are discussed.

Isolation and Characterization of Plant Growth Promoting and Metal Resistant Archaea Associated with the Rhizosphere of Salsola stocksii and Atriplex amnicola

Halophilic microorganisms play a crucial role in plant health and growth in salinity affected lands. The objective of this study was to evaluate the haloarchaeal diversity from the rhizosphere of halophytes and plant growth promoting abilities of these strains. The whole genome sequences of two haloarchaeal strains, Halorubrum lacusprofundi HL1RP11 and Halobacterium noricense NRS2HaP9, were analyzed, and genes related to plant growth promoting traits were identified. Phylogenetic analysis showed that archaeal strains of Halococcus, Halorubrum, Halobacterium and Natrinema were dominant in the rhizosphere of halophytes. More than 60% of the strains were positive for phosphate solubilization and IAA production. About 33% were siderophore producers. More than 40% of haloarchaeal strains showed the heavy metal resistance for Nickel, Cadmium, Chromium and Zinc at a concentration of 5 mM. Genes involved in plant growth promotion were identified through annotation. Gene clusters related to secondary metabolites including phenazine, siderophore production and terpene were also identified in this study. Our results suggested that these haloarchaeal strains can be used as an eco-friendly biofertilizer to improve growth and productivity in hypersaline environment.

Communicating and disseminating One Health: successes of the One Health European Joint Programme.

The application of a One Health approach recognizes that human health, animal health, plant health and ecosystem health are intrinsically connected. Tackling complex challenges associated with foodborne zoonoses, antimicrobial resistance, and emerging threats is imperative. Therefore, the One Health European Joint Programme was established within the European Union research programme Horizon 2020. The One Health European Joint Programme activities were based on the development and harmonization of a One Health science-based framework in the European Union (EU) and involved public health, animal health and food safety institutes from almost all EU Member States, the UK and Norway, thus strengthening the cooperation between public, medical and veterinary organizations in Europe. Activities including 24 joint research projects, 6 joint integrative projects and 17 PhD projects, and a multicountry simulation exercise facilitated harmonization of laboratory methods and surveillance, and improved tools for risk assessment. The provision of sustainable solutions is integral to a One Health approach. To ensure the legacy of the work of the One Health European Joint Programme, focus was on strategic communication and dissemination of the outputs and engagement of stakeholders at the national, European and international levels.

Commodity risk assessment of Prunus spinosa plants from United Kingdom.

The European Commission requested the EFSA Panel on Plant Health to prepare and deliver risk assessments for commodities listed in Commission Implementing Regulation (EU) 2018/2019 as 'High risk plants, plant products and other objects'. This Scientific Opinion covers plant health risks posed by potted plants and bundles of bare-root plants or cell grown young plants or graftwood/budwood of Prunus spinosa imported from the United Kingdom, taking into account the available scientific information, including the technical information provided by the UK. All pests associated with the commodities were evaluated against specific criteria for their relevance for this opinion. One quarantine pest, Scirtothrips dorsalis, one protected zone quarantine pest Bemisia tabaci (European population) and one non-regulated pest, the scale Eulecanium excrescens, that fulfilled all relevant criteria were selected for further evaluation. The risk mitigation measures proposed in the technical Dossier from the UK were evaluated, taking into account the possible limiting factors. For these pests, expert judgement is given on the likelihood of pest freedom, taking into consideration the risk mitigation measures acting on the pest, including uncertainties associated with the assessment. The degree of pest freedom varies among the pests evaluated, with E. excrescens being the pest most frequently expected on the imported potted plants. The Expert Knowledge Elicitation indicated with 95% certainty that between 9981 and 10,000 plants per 10,000 would be free from the above-mentioned scale.

The underground world of plant disease: Rhizosphere dysbiosis reduces above-ground plant resistance to bacterial leaf spot and alters plant transcriptome.

Just as the human gut microbiome is colonized by a variety of microbes, so too is the rhizosphere of plants. An imbalance in this microbial community, known as dysbiosis, can have a negative impact on plant health. This study sought to explore the effect of rhizosphere dysbiosis on the health of tomato plants (Solanum lycopersicum L.), using them and the foliar bacterial spot pathogen Xanthomonas perforans as model organisms. The rhizospheres of 3-week-old tomato plants were treated with either streptomycin or water as a control, and then spray-inoculated with X. perforans after 24 h. Half of the plants that were treated with both streptomycin and X. perforans received soil microbiome transplants from uninfected plant donors 48 h after the streptomycin was applied. The plants treated with streptomycin showed a 26% increase in disease severity compared to those that did not receive the antibiotic. However, the plants that received the soil microbiome transplant exhibited an intermediate level of disease severity. The antibiotic-treated plants demonstrated a reduced abundance of rhizobacterial taxa such as Cyanobacteria from the genus Cylindrospermum. They also showed a down-regulation of genes related to plant primary and secondary metabolism, and an up-regulation of plant defence genes associated with induced systemic resistance. This study highlights the vital role that beneficial rhizosphere microbes play in disease resistance, even against foliar pathogens.

Spatial distribution of Azospirillum brasilense in 2D flow cell: Effect of irrigation and inoculation regimes

AbstractRecent advances in the use of plant growth‐promoting bacteria (PGPB) have highlighted their potential to significantly enhance crop yield and plant health. In desert areas with sandy soil, employing drip irrigation systems to inoculate PGPB serves as an efficient method that saves both time and labour. This study examined the absorption, transport and spatial distribution of two strains of Azospirillum brasilense (Sp7 and Cd) under two‐dimension (2D) unsaturated transient water flow. We used sand as a substitute for sandy soil and evaluated bacterial surface characteristics, adsorption isotherms and transport under different irrigation and inoculation regimes. The research determined that, owing to its smaller size and lower adsorption, A. brasilense Cd exhibited enhanced mobility and occupied an inoculated area 33% larger than that of A. brasilense Sp7. Moreover, subsurface drip irrigation (SSDI) exhibited a 29% higher inoculation area than surface drip irrigation (SDI). The sequence of introducing PGPB suspension and irrigation water impacted the distribution, particularly for A. brasilense Sp7. The attachment/detachment numerical model adequately described the 2D bacterial distribution (R2 ranged from 0.75 to 0.99), providing a useful tool for predicting bacterial distribution in soils and optimizing agricultural practices to enhance crop productivity. Overall, smaller bacteria, SSDI inoculation and inoculation before irrigation could enhance the extent of inoculation. This study provides novel insights into optimizing PGPB inoculation strategies in agricultural settings, highlighting the importance of considering bacterial physical properties, irrigation techniques and inoculation sequences to improve PGPB distribution within the rhizosphere.

The Increased aspartate levels in transgenic cotton (Gossypium hirsutum L.) lead to improved tolerance against whitefly (Bemisia tabaci, Gennadius).

The whitefly, a polyphagous insect pest feeding on nearly 1328 plant species, is a major threat to global cotton production and incurs up to 50% yield losses in cotton production in Pakistan. We investigated whether increased aspartate in phloem sap imparts whitefly toxicity and protects cotton plants from intense damage. The enzymatic step for aspartate production is carried through aspartate aminotransferase (AAT). In this study, we constitutively overexpressed the Oryza sativa cytoplasmic AAT (OsAAT2) under the CaMV35S promoter in Gossypium hirsutum cv. CIM-482. Real-time PCR analysis of the AAT transcripts revealed a 2.85- to 31.7-fold increase in mRNA levels between the different cotton lines. A substantial increase in the free-amino acid content of the major N-assimilation and transport amino acids (aspartate, glutamate, asparagine, and glutamine) was seen in the phloem sap of the transgenic cotton lines. The bioassay revealed that the two transgenic cotton lines with the highest free aspartate content in the phloem sap exhibited 97 and 94% mortality in the adult whitefly population and a 98 and 96% decline in subsequent nymph populations, respectively. There was also a significant change in the physiological behaviour of the transgenic cotton lines, with an increased net assimilation (A), gaseous exchange (Gs) and rate of transpiration (E). Improved morphological characteristics like plant height, total number of bolls and fiber yield were recorded in transgenic cotton lines. The AAT gene shows promise in mitigating whitefly infestations and enhancing the overall health and yield of cotton plants.

Bridging aquatic invasive species threats across multiple sectors through One Biosecurity.

Understanding the magnitude of biosecurity risks in aquatic environments is increasingly complex and urgent because increasing volumes of international shipping, rising demand for aquaculture products, and growth in the global aquarium trade, are accelerating invasive alien species spread worldwide. These threats are especially pressing amid climate and biodiversity crises. However, global and national biosecurity systems are poorly prepared to respond because of fragmented research and policy environments, that often fail to account for risks across sectors or across stakeholder needs and fail to recognize similarities in the processes underpinning biological invasions. In the present article, we illustrate the complex network of links between biosecurity threats across human, animal, plant, and environment sectors and propose a universal approach to risk assessment. One Biosecurity is a holistic, interdisciplinary approach that minimizes biosecurity risks across human, animal, plant, algal, and ecosystem health and is critical to reduce redundancy and increase cross-sectoral cohesion to improve policy, management, and research in aquatic biosecurity.

Insights into the antifungal mechanism of Bacillus subtilis cyclic lipopeptide iturin A mediated by potassium ion channel

Fungal infections pose severe and potentially lethal threats to plant, animal, and human health. Ergosterol has served as the primary target for developing antifungal medications. However, many antifungal drugs remain highly toxic to humans due to similarity in cell membrane composition between fungal and animal cells. Iturin A, lipopeptide produced by Bacillus subtilis, efficiently inhibit various fungi, but demonstrated safety in oral administration, indicating the existence of targets different from ergosterol. To pinpoint the exact antifungal target of iturin A, we used homologous recombination to knock out and overexpress erg3, a key gene in ergosterol synthesis. Saccharomyces cerevisiae and Aspergillus carbonarius were transformed using the LiAc/SS-DNNPEG and Agrobacterium-mediated transformation (AMT), respectively. Surprisingly, increasing ergosterol content did not augment antifungal activity. Furthermore, iturin A's antifungal activity against S. cerevisiae was reduced while it pre-incubation with voltage-gated potassium (Kv) channel inhibitor, indicating that Kv activation was responsible for cell death. Iturin A was found to activate the Kv protein, stimulating K+ efflux from cell. In vitro tests confirmed interaction between iturin A and Kv protein. This study highlights Kv as one of the precise targets of iturin A in its antifungal activity, offering a novel target for the development of antifungal medications.

Estructura de la comunidad bacteriana asociada con raíces de Pinus montezumae Lamb. inoculado con hongos ectomicorrízicos comestibles y bacteria auxiliar de la micorriza

Tree roots are associated with a high diversity of microorganisms that play key roles in soil fertility and plant nutrition and health. Here we examine the composition and diversity of bacterial community in ectomycorrhizal root (ECR) and their ectomycorrhizosphere (EMR) of the Neotropical tree Pinus montezumae inoculated with Laccaria laccata and Hebeloma mesophaeum, applied alone or co-inoculated with Azospirillum brasilense. For this, we used a 16S rRNA gene metabarcoding-sequencing approach in samples of ECR and EMR that were collected nine-months after inoculation in greenhouse. A total of 943 Operational Taxonomic Units (OTU) were differentiated and grouped in 32 bacterial phyla. The most abundant phyla were Proteobacteria (67%) and Actinobacteria (20.7%). Bacterial communities were structured in ECR and EMR (Anosim, R=0.77, P≤0.005), and were more diverse in EMR than ECR (Shannon-Weaver of 4.2 and 3.6, and Simpson inverse of 33.7 and 16.7, respectively). The abundance of Pseudomonas, Actinoplanes and Salinibacterium were promoted with L. laccata, while with H. mesophaeum an OTU from Burkholderiaceae was prominent. Our results showed that the ectomycorrhizal fungi strongly shaped the composition of the bacterial communities associated with roots of P. montezumae.