Threat For Agriculture Research Articles

Nanoenabled Antiviral Pesticide for Tobacco Mosaic Virus: Excellent Adhesion Performance and Strong Inhibitory Effect to Alleviate the Damage on Photosynthetic System.

Tobacco mosaic virus (TMV) is a major agricultural threat. Here, a cationic star polymer (SPc) was designed to construct an efficient nanodelivery system for moroxydine hydrochloride (ABOB). ABOB could self-assemble with SPc via a hydrogen bond and van der Waals force, and this complexation reduced the particle size of ABOB from 2406 to 45 nm. With the aid of SPc, the contact angle of ABOB decreased from 100.8 to 79.0°, and its retention increased from 6.3 to 13.8 mg/cm2. Furthermore, the complexation with SPc could attenuate the degradation of ABOB in plants, and the bioactivity of SPc-loaded ABOB significantly improved with a reduction in relative viral expression from 0.57 to 0.17. The RNA-seq analysis revealed that the ABOB/SPc complex could up-regulate the expression of growth- and photosynthesis-related genes in tobacco seedlings, and the chlorophyll content increased by 2.5 times. The current study introduced an efficient nanodelivery system to improve the bioactivity of traditional antiviral agents.

Insecticidal Activity of Allium sativum Essential Oil-Based Nanoemulsion against Spodoptera littoralis.

Spodoptera littoralis, commonly known as the Egyptian or African cotton leafworm, is a significant agricultural threat. It is widely distributed in Africa, Mediterranean Europe, and Middle Eastern countries. This polyphagous pest infests numerous crop plants across 44 families, including cotton, soybeans, alfalfa, sweet potato, pepper, eggplant, tomato, maize, lettuce, strawberry, wheat, and hibiscus. The damage caused by S. littoralis on different plant organs, such as young leaves, shoots, stalks, bolls, buds, and fruits, often determines substantial product losses. Current control strategies predominantly rely on synthetic insecticides, which, despite their efficacy, have notable drawbacks, including insecticide resistance, environmental contamination, consumer concerns, and adverse effects on non-target organisms and beneficial insects. In response to these challenges, in this study, we developed and evaluated a garlic EO-based nanoemulsion with a high EO concentration (15%) and low surfactant content to mitigate the possible negative impact on plants and to enhance efficacy against S. littoralis larvae. Laboratory bioassays demonstrated promising larvicidal activity and reduced larval feeding, although some phytotoxicity symptoms were observed. This study underscores the potential of botanical insecticides as sustainable alternatives to synthetic chemicals, emphasizing the importance of balancing efficacy with environmental and ecological considerations in pest management strategies.

An update for Halyomorpha halys (Stål, 1855) (Hemiptera, Pentatomidae) distribution in Belgium

The brown marmorated stink bug, Halyomorpha halys, represents an important insect pest and subsequently an important agricultural threat due to its polyphagous feeding habits and adaptability to diverse climates. Native from East Asia, its recent establishment in various regions, including North America and Europe, has led to substantial yield losses and economic impacts, which highlight the need for comprehensive research efforts, based on data occurrence by combining those from expert entomologists and citizen scientists. We reported here 14 new occurrences of this insect pest in the three regions of Belgium. Then, these data were merged with data occurrences from other studies and GBIF datasets of Belgium. The combined dataset showed a peak of presence of Halyomorpha halys in October and a dominance of field observations from citizen scientists especially in the nothern part of Belgium, Flanders. Crowd-sourced data have provided valuable insights into the presence and distribution of Halyomorpha halys in Belgium. Given the importance of the generated dataset, it could be asserted that this pest is uniformly distributed across the entire country, which necessitates additional research to evaluate its impact on various crops.

Photodynamic Inactivation in agriculture: combating fungal phytopathogens resistant to conventional treatment

Botrytis cinerea is a severe threat in agriculture, as it can infect over 200 different crop species with gray mold affecting food yields and quality. The conventional treatment using fungicides lead to emerging resistance over the past decades. Here, we introduce Photodynamic Inactivation (PDI) as a strategy to combat B. cinerea infections, independent of fungicide resistance. PDI uses photoactive compounds, which upon illumination create reactive oxygen species toxic for killing target organisms. This study focuses on different formulations of sodium–magnesium–chlorophyllin (Chl, food additive E140) as photoactive compound in combination with EDTA disodium salt dihydrate (Na2EDTA) as cell-wall permeabilizer and a surfactant. In an in vitro experiment, three different photosensitizers (PS) with varying Chl and Na2EDTA concentrations were tested against five B. cinerea strains with different resistance mechanisms. We showed that all B. cinerea mycelial spheres of all tested strains were eradicated with concentrations as low as 224 µM Chl and 3.076 mM Na2EDTA (LED illumination with main wavelength of 395 nm, radiant exposure 106 J cm−2). To further test PDI as a Botrytis treatment strategy in agriculture a greenhouse trial was performed on B. cinerea infected bell pepper plants (Capsicum annum L). Two different rates (560 or 1120 g Ha−1) of PS formulation (0.204 M Chl and 1.279 M Na2EDTA) and a combination of PS formulation with 0.05% of the surfactant BRIJ L4 (560 g Ha−1) were applied weekly for 4 weeks by spray application. Foliar lesions, percentage of leaves affected, percentage of leaf area diseased and AUDPC were significantly reduced, while percentage of marketable plants were increased by all treatments compared to a water treated control, however, did not statistically differ from each other. No phytotoxicity was observed in any treatment. These results add to the proposition of employing PDI with the naturally sourced PS Chl in agricultural settings aimed at controlling B. cinerea disease. This approach seems to be effective regardless of the evolving resistance mechanisms observed in response to conventional antifungal treatments.Graphical abstract

Aspergillus flavus pangenome (AflaPan) uncovers novel aflatoxin and secondary metabolite associated gene clusters

BackgroundAspergillus flavus is an important agricultural and food safety threat due to its production of carcinogenic aflatoxins. It has high level of genetic diversity that is adapted to various environments. Recently, we reported two reference genomes of A. flavus isolates, AF13 (MAT1-2 and highly aflatoxigenic isolate) and NRRL3357 (MAT1-1 and moderate aflatoxin producer). Where, an insertion of 310 kb in AF13 included an aflatoxin producing gene bZIP transcription factor, named atfC. Observations of significant genomic variants between these isolates of contrasting phenotypes prompted an investigation into variation among other agricultural isolates of A. flavus with the goal of discovering novel genes potentially associated with aflatoxin production regulation. Present study was designed with three main objectives: (1) collection of large number of A. flavus isolates from diverse sources including maize plants and field soils; (2) whole genome sequencing of collected isolates and development of a pangenome; and (3) pangenome-wide association study (Pan-GWAS) to identify novel secondary metabolite cluster genes.ResultsPangenome analysis of 346 A. flavus isolates identified a total of 17,855 unique orthologous gene clusters, with mere 41% (7,315) core genes and 59% (10,540) accessory genes indicating accumulation of high genomic diversity during domestication. 5,994 orthologous gene clusters in accessory genome not annotated in either the A. flavus AF13 or NRRL3357 reference genomes. Pan-genome wide association analysis of the genomic variations identified 391 significant associated pan-genes associated with aflatoxin production. Interestingly, most of the significantly associated pan-genes (94%; 369 associations) belonged to accessory genome indicating that genome expansion has resulted in the incorporation of new genes associated with aflatoxin and other secondary metabolites.ConclusionIn summary, this study provides complete pangenome framework for the species of Aspergillus flavus along with associated genes for pathogen survival and aflatoxin production. The large accessory genome indicated large genome diversity in the species A. flavus, however AflaPan is a closed pangenome represents optimum diversity of species A. flavus. Most importantly, the newly identified aflatoxin producing gene clusters will be a new source for seeking aflatoxin mitigation strategies and needs new attention in research.

High levels of genetic variation and differentiation in wild tropical gourds provide a novel resource for cucurbit crop improvement

Social Impact StatementThe genetic variation of crop wild relatives will be key for our survival, as environmental change represents an increasing global threat for agriculture and food security. Cucurbita lundelliana and Cucurbita okeechobeensis subsp. martinezii are wild relatives of cultivated squashes and pumpkins that could be used for crop improvement. A genomic approach was used to characterize genetic resources in these taxa, that is, to identify candidate sites in the genome involved in responses to abiotic stress, and to understand the roles of gene flow and environmental differentiation in their divergence. This study highlights the importance of conserving these two species as phytogenetic resources for crop improvement.Summary Crop wild relatives (CWR) are reservoirs of genetic diversity and they are important for the maintenance of crop evolutionary potential. Mexico is the centre of domestication and diversity for many CWR. The genus Cucurbita originated in America, where at least six independent domestication events took place. Nonetheless, Cucurbita CWR have been seldom studied. In the present study, we test the role of incomplete lineage sorting (ILS) and secondary contact in the divergence of C. okeechobeensis subsp. martinezii and C. lundelliana. Additionally, we seek to understand the role of environmental differentiation in their divergence. We obtained 1,638 single nucleotide polymorphisms (SNPs) for 107 individuals from the most recently diverged wild species in this genus, encompassing 25 localities of C. lundelliana and nine localities of C. okeechobeensis subsp. martinezii in Mexico. We found higher genetic variation in C. lundelliana (HE = 0.227) than in C. okeechobeensis subsp. martinezii (HE = 0.187). Each taxon constitutes a well‐differentiated genetic group, with an area of introgression in Pantanos de Centla. We found candidate loci associated to hydric and thermal stress, which could be valuable for crop improvement. Our study supported a scenario of ILS followed by secondary contact, where divergence was probably driven by Pleistocene climate change. These CWR represent important phytogenetic resources for crop improvement given their high levels of genetic variation and differentiation and their SNPs associated to different climatic variables.

Compuestos bioactivos de bacterias y hongos en el control de nematodos fitopatógenos: mecanismos de acción, interacciones y aplicaciones

Phytopathogenic nematodes are a threat for agriculture, they cause plant diseases and economic losses worldwide. Currently, the pursuit of compounds of biological origin for nematode biocontrol has become a priority as an environmentally friendly alternative. Microorganisms-derived compounds have several strategies to reduce the populations of infectious juvenile nematodes. Although microorganisms and their metabolites are the focus of literature reports reviews on nematicidal control, interactions between fungi, bacteria, and nematodes, as well as the compounds that are generated in such interactions, are not highlighted. The aim of this review was to discuss the latest advances on chemical compounds secreted by microorganisms and their interaction mechanisms for biological control of phytopathogenic nematodes. Results were organized based on: i) mode of action, ii) infection process, iii) nematicide compounds, iv) interactions and field applications, and v) current challenges. The scope of this review contributes to a better comprehension of the versatility of bacterial and fungal compounds for their use in the development of management plans for nematode control.

Understanding variation in impacts from private protected areas across regions and protection mechanisms to inform organizational practices.

Private land protection is an important and growing tool to address biodiversity loss and climate change. Thus, better empirical evidence on the effectiveness of private land protection and organizational practices, such as targeting of lands for protection and choice of protection mechanism (i.e., fee simple land acquisition and conservation easements), is needed. We addressed this gap by estimating the impacts of The Nature Conservancy's (TNC) (a large nongovernmental organization with relatively decentralized management) conservation land acquisitions and easements from 1988 to 2016 in three regions of the United States (Mid-Atlantic, New England and New York, and California). We estimated impact in terms of avoided conversion by comparing natural land cover on 3179 protected parcels with matched unprotected parcels. Nineteen of 21 ecoregional plans used threats of agriculture and development to identify priorities for protection. When regions and protection mechanisms were pooled, on average there was no evidence of avoided conversion from 1988 to 2016. Accounting for mechanisms, TNC land acquisitions avoided conversionand easements did not. TNC's easements on parcels acquired by conservation partners did avoid conversion. Limitations of these results include focus on a singlemeasure of impact, inability to capture future avoided conversion, and low land cover change accuracy in California. Our results suggest that private land protection managers who seek to avoid land conversion in the near to medium term should increase focus on areas with higher threats. Special attention should be paid to strengthening accountability and the role of partners, improving or clarifying how easements are used, and facilitating the flow of resources to work with the greatest potential impact.

Comparative anti-inflammatory effect of extract from novel Korean strawberry cultivars (Fragaria × ananassa) on lipopolysaccharide-induced RAW264.7 macrophages and mouse model.

Dietary interventions are crucial in modulating inflammation in humans. Strawberries are enjoyed by people of different ages as a result of their attractive phenotype and taste. In addition, the active compounds in strawberries may contribute to the reduction of inflammation. When developing new strawberry cultivars to address agricultural and environmental threats, the bioactivity of strawberries must be improved to maintain their health benefits. We determined the phytochemical contents of extracts from a new Korean strawberry cultivar, with the CN7 cultivar extract possessing the highest total polyphenol and flavonoid contents compared to the CN5 and Seolhyang cultivar extracts. The new Korean strawberry cultivars reduced the expression of inflammatory-related genes in lipopolysaccharide (LPS)-induced RAW264.7 cells via the nuclear factor-kappa B signaling pathway, indicating an anti-inflammatory effect. The CN7 cultivar showed greater bioactivity potential and the highest ellagic acid content; hence, we assessed the effect of the CN7 cultivar in an LPS-stimulated mouse model. The CN7 cultivar treatment demonstrated its effectiveness in reducing inflammation via the downregulation of inflammatory cytokines secretion and gene expression. The results obtained in the present study have revealed the observable differences of the newly developed strawberry cultivars with Seolhyang in mitigating inflammation induced by LPS. The enhanced phytochemical content of the CN7 cultivar extract may contribute to its improved anti-inflammatory effect. Therefore, it is crucial to maintain the nutritive benefits of strawberry during the development of new cultivation. © 2023 Society of Chemical Industry.

Occurrence of Insect-Pest of Cluster Bean [Cyamopsis tetragonoloba (Linn.) Taubert] Associated with Meteorological Parameters in Gird Region of Madhya Pradesh, India

Insects are a big threat in agriculture. To study about insect pests complex of the cluster bean, a field experiment conducted at Research Farm, Rajmata Vijyaraje Scindia Krishi Vishwa Vidyalaya, Gwalior, Madhya Pradesh during Kharif season 2022-23. The incidence of insect pests observed on kharif cluster bean, namely thrips, Megleurothrips distalis (karny), Jassid, Empoasca kerri (Pruthi) aphid, Aphis craccivora (Koch) and whiteflies, Acaudaleyrodes rachipora (Singh). Peak population of aphid, Jassid and whitefly were observed during 37th SMW (2nd week of September) (4.39, 5.74 and 5.67 individuals/leaf, respectively); while peak population of thrips were observed during 38th SMW (3rd week of September) (4.75 individuals/leaf), thrips peak population was observed 38th SMW (3rd week of August) (3.70 thrips/leaf). Population of aphid and Jassid showed positive significant correlation with rainfall (r= 0.505*) and (r= 0.498*), respectively. Population of aphid, jassid and whitefly showed highly significant positive correlation with minimum temperature (r= 0.684**), (r= 0.745**) and (r= 0.591*), respectively. Population of aphid, jassid, thrips and whitefly showed significant positive correlation with evening relative humidity (r= 0.606*), (r= 0.621*), (r= 0.511*) and (r= 0.498*).

The role of conservation in United States' agricultural policy from the Dust Bowl to today: A critical assessment.

Historical evidence shows that environmental issues have been secondary to United States' agricultural policy since the first farm bill in 1933. The farm sector has undergone massive changes in technology and farming practices, but the environmental problems it causes have remained ancillary to productivist goals. Agri-environmental policy has continued to rely on subsidies and voluntary farmer participation, while combining environmental objectives with price and income support aims. The faith of agri-environmental programs is largely determined by what is desirable for safety net purposes, and in times of high crop and livestock prices and increased environmental pressures conservation is particularly underfunded. Additionally, monitoring and program assessment are poorly structured. This is particularly concerning today given the threats of climate change and agriculture's contribution to it. A major rethinking of these taxpayer-funded programs is necessary to improve their effectiveness. Programs should focus on environmental outcomes and monitoring and assessment should be strengthened.

Plant-Associated Neoscytalidium dimidiatum-Taxonomy, Host Range, Epidemiology, Virulence, and Management Strategies: A Comprehensive Review.

Neoscytalidium dimidiatum, a plant- and human-associated fungus, has emerged as a substantial global ecological and agricultural threat aggravated by global warming. It inflicts various diseases, including canker, blight, dieback, leaf spot, root rot, and fruit rot, across a wide spectrum of fruit trees, field crops, shrubs, and arboreal species, with a host range spanning 46 plant families, 84 genera, and 126 species, primarily affecting eudicot angiosperms. Six genera are asymptomatic hosts. Neoscytalidium dimidiatum exhibits worldwide distribution, with the highest prevalence observed in Asia and North America, notably in Iran, Turkey, and California. Rising disease prevalence and severity, aggravated by climate change, particularly impact tropical arid places across 37 countries spanning all 7 continents. This comprehensive review encapsulates recent advancements in the understanding of N. dimidiatum, encompassing alterations in its taxonomic classification, host range, symptoms, geographic distribution, epidemiology, virulence, and strategies for effective management. This study also concentrates on comprehending the taxonomic relationships and intraspecific variations within N. dimidiatum, with a particular emphasis on N. oculus and N. hylocereum, proposing to consider these two species as synonymous with N. dimidiatum. Furthermore, this review identifies prospective research directions aimed at augmenting our fundamental understanding of host-N. dimidiatum interaction.

Diversification as a strategy for ensuring security of business subjects in the agricultural sector

Agricultural business is one of the riskiest types of economic activity. In addition to the set of traditional risks, there are threats in agriculture caused by the specifics of agrarian entrepreneurship, which require the search for appropriate strategies and tools for neutralization. Diversification of economic activities of agricultural producers appears as one of these tools. The article examines vital risks that threaten the safe development of agrarian business entities. The main trends in the activity of Ukrainian agricultural enterprises during the last ten years and directly impacted the diversification processes of their economic activity were determined. Price (market) risks were identified as the determining risks of activating diversification processes. Existing processes and trends significantly influenced the formation of the philosophy and main principles of agrarian business, of which the commercial interests of the owners of agricultural structures became the priority. The article assesses the dynamics of the diversification level of agricultural enterprises' economic activity. It was revealed that over the past twenty years, the balance of the development of industries and their share in the structure of agricultural production has been disturbed. The specific weight of agribusiness structures' agricultural services and other non-agricultural activities remained practically unchanged. An analysis of the diversification structure of the plant and animal husbandry industries was carried out. The results showed the presence of problematic structural shifts, which are a consequence of the unjustified deepening of specialization of agricultural enterprises. It was revealed that the curtailment of diversification processes led to the disruption of the intra-industry structure and the emergence of threats to the disappearance of specific sub-sectors of domestic agriculture. Despite this, the agricultural sector of the Ukrainian economy has demonstrated a relatively high level of sustainability and efficiency. It was determined that diversification is an element of strategic agricultural management, which has a significant potential for reducing the level of riskiness of agrarian business and forming prerequisites for achieving the goals of sustainable development of agriculture and rural areas. Keywords: agricultural enterprises, business, diversification, risks, security, agricultural management.

Safeguarding Agriculture: A Comprehensive Review of Plant Protection Strategies

The rapidly evolving landscape of agriculture faces myriad challenges, including pests, diseases, and environmental factors that jeopardise global food security. The urgency of these challenges necessitates innovative plant protection strategies that are both effective and environmentally sustainable. This review offers a comprehensive examination of the advancements and considerations in plant protection, from traditional methods to modern technological approaches. Traditional practices, although eco-friendly, often fall short in efficacy and scalability. The advent of chemical solutions such as pesticides revolutionised plant protection but brought about environmental and health concerns. Biological controls offer a middle-ground, leveraging natural predators and bio-pesticides to combat agricultural threats. Technology is playing an increasingly critical role in shaping the future of plant protection. Sensor technologies and drones are enabling precision agriculture, enhancing the monitoring and application of protection measures. Genetic engineering holds the promise of creating crops resistant to pests and diseases, albeit amid ethical and safety debates. Integrated Pest Management (IPM), a balanced, eco-friendly approach, is gaining traction, supported by case studies that validate its effectiveness and adaptability. Meanwhile, policy and regulation are evolving to better govern the use of chemicals, promote sustainability, and address the impacts of climate change on agriculture. This review explores future trends, particularly the influence of emerging technologies such as nanotechnology and IoT, and potential shifts in global policies towards more sustainable practices. It argues for the imperative of integrating these multifaceted approaches, guided by robust policies and regulations, to achieve the dual objectives of high agricultural yield and environmental conservation. It aims to provide a holistic understanding and guide future directions in plant protection strategies, emphasising the importance of adaptability, sustainability, and integration in facing the challenges of tomorrow.

Soil Erosion Estimation of Kunthippuzha Watershed Using GIS and RUSLE Model

Soil erosion is an environmental crisis in the world today that threatens the natural environment and also agriculture. Erosion removes the top fertile soil, degrades soil fertility, water quality and soil productivity. The soil erosion risk assessment is helpful for land evaluation in the regions where soil erosion is a major threat for sustainable agriculture. Modelling can provide a quantitative and consistent approach to estimate soil erosion and sediment yield under a wide range of conditions. The soil erosion and erosion prone areas in the Kunthippuzha sub-watershed of Bharathapuzha river basin, Kerala, India was estimated using RUSLE. The study area is having a drainage area of 950 km2 up to the gauging station. The estimation was done for 1990 to 2021. The estimated rainfall erosivity, soil erodibility, Slope length and slope steepness factor and crop management factors range from 929.36 and 980.38 MJ mm ha-1 h-1 yr-1, 0.01387 to 0.0385 t ha h ha−1 MJ−1 mm−1, 0 to 9.77 and 0.057796 to 1.0999. The results indicate that the estimated total annual potential soil loss of about 842175 t/y is comparable with the measured sediment of 845500 t/yr during the years 1990-2021. The soil erosion rate categorized into six classes based on the erosion severity, the major portion (60%) of the study area comes under very slight erosion zone and only a small portion (14%) comes under severe and very severe erosion zone. Result suggests the area of the north-eastern part suffers from a high soil erosion risk due to steep slope. The results can certainly aid in implementation of soil management and conservation practices to reduce the soil erosion in the Kunthippuzha sub-watershed.

Natural Oil Lure Outperforms Trimedlure in Capturing Males of the Mediterranean Fruit Fly, Ceratitis capitata (Diptera: Tephritidae).

Females of certain tephritid fruit fly species (Diptera: Tephritidae) pose an enormous agricultural threat, as they oviposit in commercially important fruits and vegetables. Trapping networks are often operated in fruit fly-free areas to detect incipient infestations. Trapping relies largely on male attractants, so-called male lures, with trimedlure (TML) being used to detect invasive Ceratitis spp. Operating large-scale surveillance programs incurs substantial costs for both supplies and labor, and the problem is exacerbated by the fact that trimedlure (as well as other male lures) is effective for relatively short intervals in the field (6-8weeks). Because frequent servicing increases costs, there is considerable interest in modifying existing lures or developing new formulations to extend their effective field longevity. Here, we present results of a field study in Hawaii on a wild population of the Mediterranean fruit fly, Ceratitis capitata (Wiedemann), that compared male captures in traps baited with (i) fresh liquid TML, (ii) TML plugs, (iii) a novel controlled-release TML sachet, and (iv) a novel natural oil blend dispensed from a sachet. Catch was recorded weekly for 12weeks and then at 16 and 20weeks, with 12 traps deployed per treatment. The natural oil formulation, which contains the natural plant product α-copaene, was as effective as the fresh liquid TML even after weathering for 20weeks. Future work will focus on developing a dispenser for this formulation that is compatible with standard trap design and deployment.

Soil and water pollution an update on the status of selected Indian states and cities

Pollution is now the main problem for man and his survival. Waste, which can originate from any source, whether mining, industrial, biological or household, is now on the priority list of all countries? The treatment and disposal of waste is a source of local and central government concern. The methods used to dispose of waste create a new problem for society. Dumping solid waste and burying it underground pollutes the soil and handling liquid waste on the ground or in water both causes pollution. Therefore, the pollution caused by the continuous disposal of wastes underground and in the water is not only harmful to the environment, but also has a negative impact on the health of living organisms. This review aims to highlight the status of several Indian states and cities that are suffering from soil and water pollution. The review will attempt to shows oil and water standards, heavy metal status, seasonal changes in soil and water pollution, contaminated agricultural crops, pollution pathways, uses and threat to living organisms.

Gibberellins promote seed conditioning by up-regulating strigolactone receptors in the parasitic plant Striga hermonthica.

Dormant seeds of a root parasitic plant Striga hermonthica sense strigolactones from host plants as environmental cues for germination. This process is mediated by diversified member of strigolactone receptors encoded by HYPOSENSITIVE TO LIGHT/KARRIKIN INSENSITIVE2 genes. It is known that warm and moist treatment of seed conditioning gradually turns dormant Striga seeds competent to respond strigolactones, while the mechanism behind it has been poorly understood. In this report, we show that plant hormone gibberellins increase the strigolactone-competence by up-regulating mRNA expressions of the major strigolactone receptors during the conditioning period. This idea was supported by poor germination phenotype when gibberellin biosynthesis is depleted by paclobutrazol during conditioning. Moreover, live-imaging with fluorogenic strigolactone-mimic, yoshimulactone green W, revealed that paclobutrazol treatment during conditioning caused aberrant dynamics of strigolactone perception after germination. These observations revealed an indirect role of gibberellins to the seed germination in Striga, which is contrastive to their roles as dominant germination stimulating hormone in non-parasitic plants. We propose a model of how the role of gibberellins become indirect during the evolution of parasitism in plants. Our work also highlight the potential role for gibberellins in field application, for instance, elevating the sensitivity of the seeds towards strigolactones in the current suicidal germination approach to alleviate the agricultural threats caused by this parasite in Africa.

Application of multi-criteria decision analysis techniques and decision support framework for informing select agent designation for agricultural animal pathogens.

The United States Department of Agriculture (USDA), Division of Agricultural Select Agents and Toxins (DASAT) established a list of biological agents and toxins (Select Agent List) that potentially threaten agricultural health and safety, the procedures governing the transfer of those agents, and training requirements for entities working with them. Every 2years the USDA DASAT reviews the Select Agent List, using subject matter experts (SMEs) to perform an assessment and rank the agents. To assist the USDA DASAT biennial review process, we explored the applicability of multi-criteria decision analysis (MCDA) techniques and a Decision Support Framework (DSF) in a logic tree format to identify pathogens for consideration as select agents, applying the approach broadly to include non-select agents to evaluate its robustness and generality. We conducted a literature review of 41 pathogens against 21 criteria for assessing agricultural threat, economic impact, and bioterrorism risk and documented the findings to support this assessment. The most prominent data gaps were those for aerosol stability and animal infectious dose by inhalation and ingestion routes. Technical review of published data and associated scoring recommendations by pathogen-specific SMEs was found to be critical for accuracy, particularly for pathogens with very few known cases, or where proxy data (e.g., from animal models or similar organisms) were used to address data gaps. The MCDA analysis supported the intuitive sense that select agents should rank high on the relative risk scale when considering agricultural health consequences of a bioterrorism attack. However, comparing select agents with non-select agents indicated that there was not a clean break in scores to suggest thresholds for designating select agents, requiring subject matter expertise collectively to establish which analytical results were in good agreement to support the intended purpose in designating select agents. The DSF utilized a logic tree approach to identify pathogens that are of sufficiently low concern that they can be ruled out from consideration as a select agent. In contrast to the MCDA approach, the DSF rules out a pathogen if it fails to meet even one criteria threshold. Both the MCDA and DSF approaches arrived at similar conclusions, suggesting the value of employing the two analytical approaches to add robustness for decision making.

Probe-based quantitative PCR and RPA-Cas12a molecular diagnostics for detection of the tomato pest Phthorimaea absoluta (Lepidoptera: Gelechiidae).

The tomato pest Phthorimaea absoluta Meyrick is highly invasive but has not yet invaded North America. However, several morphologically similar species are already present, making detection of P. absoluta presence and invasion challenging. We designed a quantitative PCR molecular diagnostic to differentiate P. absoluta, P. operculella (Zeller), or Keiferia lycopersicella (Walsingham) (Lepidoptera: Gelechiidae) DNA. Additionally, we developed an RPA-Cas12a molecular diagnostic that allows for the isothermal detection of P. absoluta DNA, eliminating the need for a thermocycler. The results of the RPA-Cas12a diagnostic can be visualized simply using a UV light source and cell phone camera. We expect these diagnostics to improve quarantine and prevention measures against this serious agricultural threat.