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National audience; Cell wall integrity is crucial for fungal growth, development and stress survival. In yeast, Slt2MAP kinase and calcineurin signaling pathways monitor cell wall repair during stress and development. MPS1, the M. grisea SLT2 orthologue, is essential for cell wall repair and for appressorium mediated penetration into host plants (Xu 1998 PNAS 95:12713). In yeast, Slt2 activates the transcription factors Rlm1, Swi4 and Swi6, while calcineurin activates Crz1. Genes orthologous to yeast CRZ1, MPS1, RLM1, SWI4, and SWI6 genes were identified in M. grisea genome. Swi4 and Swi6 interact with Mps1 in yeast two hybrid assays. Deletion mutants were constructed by targeted gene replacement in M. grisea. Delta-mps1 mutants displayed an abnormal mycelial growth (no aerial hyphae), did not sporulate, and were nonpathogenic on plants as reported. Delta-crz1, delta-rlm1, delta-swi6 mutants have a normal mycelial growth and sporulation rates similar to wild type. Of these three mutants, only delta- Rlm1 displays a highly reduced pathogenicity on barley and rice (-98%, lesion number). Delta-mps1 mutants are highly sensitive to nikkomycin Z (chitin synthase inhibitor), CFW (disorganization of cell wall) and aculeacine (glucan synthase inhibitor), while delta-crz1 and delta-rlm1 mutant are only mildly hypersensitive to Nikkomycin, and delta-swi6 mutant is only slightly hypersensitive to CFW. These studies suggest that the transcription factors controlled by Mps1 are either functionally redundant or specialized in the control of specific target genes.

National audience

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IRAC-US is a specialist technical group of CropLife America. It provides a coordinated crop protection industry response to prevent or delay the development of resistance in insect and mite pests. Its aim is to keep all classes of insecticides and acaricides as viable control options. The neonicotinoid subcommittee of IRAC, U.S. has developed resistance management guidelines for the use of the neonicotinoid class of chemistry. For additional information about IRAC, US visit the website: www.irac-online.org. Accepted for publication 6 July 2006. Published 19 July 2007.

The present invention relates to a composition comprising a) a pesticidal terpene mixture comprising, as pesticidally active chemical compounds, alpha-terpinene, p-cymene and limonene and b) at least one biological control agent selected from specific microorganisms and/or a mutant of it having all identifying characteristics of the respective strain, and/or a metabolite produced by the respective strain that exhibits activity against insects, mites, nematodes and/or phytopathogens in a synergistically effective amount. Furthermore, the present invention relates to the use of this composition as well as a method for reducing overall damage of plants and plant parts.

Disclosed are herbicidal agents containing A) a compound from the group comprising benzoylpyrazoles, B) at least one additional herbicide, and C) at least one safener, as herbicides that are effective against monocotyledonous and/or dicotyledonous weeds. Said agents are provided with an effect that is superior to the effect of the herbicides used individually while featuring a high degree of cultigen compatibility.

The invention relates to novel heterocyclic compounds, to their use for controlling animal pests, which include arthropods, insects and nematodes, and to methods and intermediate products for producing said novel compounds.

The invention relates to thiazolylpiperidine derivates of the formula (I), where the symbols A, G, Y, n, R1, R2, R3, R4, and R5 have the meanings given in the description, and to agrochemically active salts thereof, and the use thereof for treating plant pathenogenic fungi, and to the method for producing compounds of the formula (I).

The invention relates inter alia to halogen-substituted compounds of general formula (I), in which the radicals A1-A4, T, W, Q, R1 and Z1-Z3 have the meaning cited in the description. The invention also relates to methods for producing the compounds of formula (I). The compounds according to the invention are in particular suitable for controlling insects, arachnids and nematodes in agricultural applications and for controlling ectoparasites in veterinary medicine.

The invention relates to novel DELTA

The invention relates to polypeptides which perform the biological activity of a helicokinin-receptor, in addition to polynucleotides which code for said polypeptides and especially the use thereof for detecting active ingredients for the protection of plants.

The present invention relates to a novel process for the preparation of compounds of the formula (I) (I)by reacting in a first step amino alcohols of the formula (II) (II)with oleum to give sulphuric acid esters of the general formula (III) (III)and by reacting these sulphuric acid esters in a second step with mercaptans or salts thereof of the general formula (IV) (IV)in each formula, where applicable, R1, R2, R3, R4, R5, R6, R, n and M have the meanings given in the description,in the presence of a diluent and in the presence of a base.

The invention relates to an electrolysis cell for particularly efficient treatment of waste water polluted with organic substances by electro-oxidative degradation of waste water components that contribute to the chemical oxygen demand and the use thereof.

The present invention relates to the novel use of Isotianil or Tiadinil for inducing latent host defenses in a plant. In particular, the present invention relates the use of Isotianil or Tiadinil for inducing latent host defenses that are activated in the event of an attack by a phytopathogenic pathogen or pestor or of abiotic stress. The invention further relates to the induction of latent host defenses in a plant which comprises the priming of the intrinsic disease resistance mechanisms of a plant.

The invention relates to substituted pyrimidines of general formula (I), in which n, R1, R2, R3 et Z have the meaning indicated in the description, to the use thereof as plant treatment products, in particular as herbicides and to a method for the production thereof.

The invention relates to the use of selective insecticides for controlling insects and/or arachnids. Said insecticides are characterized by an active moiety of an active substance combination comprising (a) at least one compound of formula (I), wherein CKE, W, X, Y, and Z have the meaning indicated in the description, and (b) at least one compound which improves crop plant tolerance and is part of the group of compounds indicated in the description. Also disclosed is a method for controlling insects and/or arachnids using the inventive insecticides.

The invention relates to 4-(3-alkyl sulfinyl benzoyl) pyrazoles of the general formula (I) as herbicides. In said formula (I), R1 through R4, X, and Y stand for radicals such as hydrogen, organic radicals such as alkyls, and other radicals such as halogens.

Glyphosate-resistant (GR) Italian ryegrass (LOLMU) and Alexandergrass (URPLA) are troublesome weeds in corn cropping systems in Southern Brazil. The emergence pattern of those weeds is not uniform and may change according to the season?s environmental characteristics. Also, herbicide resistance has been diminishing the success of the weed control programs. The objectives of this study were to evaluate the influence of corn-sowing date on LOLMU and URPLA densities and their control provided by pre- and post-emergent herbicides. Field trials were conducted in two crop seasons in Southern Brazil consisting of three corn sowing date (August, September, and October) and the application of atrazine + S-metolachlor (residual) in corn pre-emergence in different post-emergence weed control programs with glyphosate, ammonium-glufosinate, nicosulfuron, and atrazine. The results indicated that the sowing date had a significant influence on LOLMU and URPLA densities. Corn sown in the earliest period was exposed to a higher LOLMU density, whereas corn sown in the latest period had a higher density of URPLA. Also, the application of residual herbicide at corn pre-emergence reduced both weed species densities and decreased the pressure for the control of glyphosate-resistant LOLMU for the post-emergence herbicides. The use of residual herbicides in corn pre-emergence is an efficient strategy to be considered in the LOLMU and URPLA control programs, followed by post-emergence application of glyphosate, ammonium-glufosinate, atrazine, and nicosulfuron. Made available in DSpace on 2021-02-09T13:18:35Z (GMT). No. of bitstreams: 1 Piasecki-2020-285.pdf: 264629 bytes, checksum: 9eae754ec72262cd23e97e0716fd8e5f (MD5) Previous issue date: 2020

International audience; From several decades, some organophosphorus compounds specifically designed to alterbiological systems were introduced on market as agrochemicals (ie glyphosate and glufosinate asherbicides). Nevertheless, it becomes necessary to find new compounds in order to counter plantresistances already observed with glyphosate. Fosmidomicyn and its N-acetyl analogues FR-900098 were perceived as starting points for elaboration of new herbicide candidates, targetingthe second enzyme of the non-mevalonate pathway in plants, the 1-deoxy-D-xylulose 5-phosphate reductoisomerase (DOXP reductoisomerase or DXR). It is expected that theenhancement of bioactivity compared to the parent compounds, might be reached by insertion oftwo fluorine atoms close to the phosphonate function. Indeed, the presence of both fluorineatoms could improve the lipophilicity, affect the pKa of the phosphonic acid function and theninduce better activities. Herein, the synthesis of gem-difluorinated analogues of retrohydroxamicfosmidomycin and FR-900098-ester is reported using a radical addition mediated by acobaloxime complex

International audience; Magnaporthe oryzae is a fungal plant pathogen of many grasses including rice. Since arabinoxylan is one of the major components of the plant cell wall of grasses, M. oryzae is likely to degrade this polysaccharide for supporting its growth in infected leaves. D-Xylose is released from arabinoxylan by fungal depolymerising enzymes and catabolized through the pentose pathway. The expression of genes involved in these pathways is under control of the transcriptional activator XlnR/Xlr1, conserved among filamentous ascomycetes. In this study, we identified M. oryzae genes involved in the pentose catabolic pathway (PCP) and their function during infection, including the XlnR homolog, XLR1, through the phenotypic analysis of targeted null mutants. Growth of the Delta xlr1 strain was reduced on D-xylose and xylan, but unaffected on L-arabinose and arabinan. A strong reduction of PCP gene expression was observed in the Delta xlr1 strain on D-xylose and L-arabinose. However, there was no significant difference in xylanolytic and cellulolytic enzyme activities between the Delta xlr1 mutant and the reference strain. These data demonstrate that XLR1 encodes the transcriptional activator of the PCP in M. oryzae, but does not appear to play a role in the regulation of the (hemi-) cellulolytic system in this fungus. This indicates only partial similarity in function between Xlr1 and A. niger XlnR. The deletion mutant of D-xylulose kinase encoding gene (XKI1) is clearly unable to grow on either D-xylose or L-arabinose and showed reduced growth on xylitol, L-arabitol and xylan. Delta xki1 displayed an interesting molecular phenotype as it over-expressed other PCP genes as well as genes encoding (hemi-) cellulolytic enzymes. However, neither Delta xlr1 nor Delta xki1 showed significant differences in their pathogeny on rice and barley compared to the wild type, suggesting that p-xylose catabolism is not required for fungal growth in infected leaves. (C) 2013 Elsevier Inc. All rights reserved.

Fusarium head blight in wheat spikes is associated with production of mycotoxins by the fungi. Although flowering is recognized as the most favourable host stage for infection, a better understanding of infection timing on disease development and toxin accumulation is needed. This study monitored the development of eight characterized isolates of F. graminearum, F. culmorum and F. poae in a greenhouse experiment. The fungi were inoculated on winter wheat spikes before or at anther extrusion, or at 8, 18 and 28 days later. Disease levels were estimated by the AUDPC and thousand-kernel weight (TKW). The fungal biomass (estimated by qPCR) and toxin concentration (deoxynivalenol and nivalenol, estimated by UPLC-UV-MS/MS) were measured in each inoculated spike, providing a robust estimation of these variables and allowing correlations based on single-individual measurements to be established. The toxin content correlated well with fungal biomass in kernels, independently of inoculation date. The AUDPC was correlated with fungal DNA, but not for early and late infection dates. The highest disease and toxin levels were for inoculations around anthesis, but early or late infections led to detectable levels of fungus and toxin for the most aggressive isolates. Fungal development appeared higher in kernels than in the chaff for inoculations at anthesis, but the opposite was found for later inoculations. These results show that anthesis is the most susceptible stage for FHB, but also clearly shows that early and late infections can produce significant disease development and toxin accumulation with symptoms difficult to estimate visually.

Because aquatic macroinvertebrates may be exposed regularly to pesticides in edge-of-the-field water bodies, an accurate assessment of potential adverse effects and subsequent population recovery is essential. Standard effect risk assessment tools are not able to fully address the complexities arising from multiple exposure patterns, nor can they properly address the population recovery process. In the present study, we developed an individual-based model of the freshwater amphipod Gammarus pulex to evaluate the consequences of exposure to 4 compounds with different modes of action on individual survival and population recovery. Effects on survival were calculated using concentration-effect relationships and the threshold damage model (TDM), which accounts for detailed processes of toxicokinetics and toxicodynamics. Delayed effects as calculated by the TDM had a significant impact on individual survival and population recovery. We also evaluated the standard assessment of effects after short-term exposures using the 96-h concentration-effect model and the TDM, which was conservative for very short-term exposure. An integration of a TKTD submodel with a population model can be used to explore the ecological relevance of ecotoxicity endpoints in different exposure environments.

International audience; A gene (MoPRD1), related to xylose reductases, was identified in Magnaporthe oryzae. Recombinant MoPRD1 displays its highest specific reductase activity toward L-arabinose and D-xylose. K-m and V-max values using L-arabinose and D-xylose are similar. MoPRD1 was highly overexpressed 2-8 h after transfer of mycelium to D-xylose or L-arabinose, compared to D-glucose. Therefore, we conclude that MoPDR1 is a novel pentose reductase, which combines the activities and expression patterns of fungal L-arabinose and D-xylose reductases. Phylogenetic analysis shows that PRD1 defines a novel family of pentose reductases related to fungal D-xylose reductases, but distinct from fungal L-arabinose reductases. The presence of PRD1, L-arabinose and D-xylose reductases encoding genes in a given species is variable and likely related to their life style. (C) 2013 Federation of European Biochemical Societies. Published by Elsevier B. V. All rights reserved.

Germination vigor is driven by the ability of the plant embryo, embedded within the seed, to resume its metabolic activity in a coordinated and sequential manner. Studies using “-omics” approaches support the finding that a main contributor of seed germination success is the quality of the messenger RNAs stored during embryo maturation on the mother plant. In addition, proteostasis and DNA integrity play a major role in the germination phenotype. Because of its pivotal role in cell metabolism and its close relationships with hormone signaling pathways regulating seed germination, the sulfur amino acid metabolism pathway represents a key biochemical determinant of the commitment of the seed to initiate its development toward germination. This review highlights that germination vigor depends on multiple biochemical and molecular variables. Their characterization is expected to deliver new markers of seed quality that can be used in breeding programs and/or in biotechnological approaches to improve crop yields.

International audience; Fungal secretomes are known to contain a multitude of components involved in nutrition, cell growth or biotic interactions. Recently, extra-cellular vesicles have been identified in a few fungal species. Here, we used a multidisciplinary approach to identify and characterize extracellular vesicles produced by the plant necrotroph Botrytis cinerea. Transmission electron microscopy of infectious hyphae and hyphae grown in vitro revealed extracellular vesicles of various sizes and densities. Electron tomography showed the co-existence of ovoid and tubular vesicles and pointed to their release via the fusion of multi-vesicular bodies with the cell plasma membrane. The isolation of these vesicles and exploration of their protein content using mass spectrometry led to the identification of soluble and membrane proteins involved in transport, metabolism, cell wall synthesis and remodeling, proteostasis, oxidoreduction and traffic. Confocal microscopy highlighted the capacity of fluorescently labeled vesicles to target cells of B. cinerea, cells of the fungus Fusarium graminearum, and onion epidermal cells but not yeast cells. In addition, a specific positive effect of these vesicles on the growth of B. cinerea was quantified. Altogether, this study broadens our view on the secretion capacity of B. cinerea and its cell-to-cell communication.

International audience; Proteome analysis, which involves the identification and characterization of expressed proteins, is a powerful tool for determining the biological roles and functions of individual proteins. Furthermore, by providing a systematic and without any a priori mean for large-scale identification of cellular proteins, proteomics is expected to accelerate discoveries in complex processes such as development. Allied to other genome-scale gene expression profiling methods as transcriptomics and metabolomics, proteomics also constitutes a powerful tool toward the development of modern systems biology, an emerging approach that seeks to biological systems through integration of diverse types of massive data and which will ultimately allow computational simulations of these complex systems, notably in plants.

International audience; The ascomycete Magnaporthe grisea is a model species for the study of plant fungal interactions. As in many filamentous fungi, targeted gene replacement occurs at low frequency in M. grisea (average 7%). mus52/KU80 is a gene essential for non-homologous end joining (NHEJ) of DNA double-strand breaks. Its deletion increases the frequency of targeted gene replacement in fungi [Ninomiya, Y., Suzuki, K., Ishii, C., Inoue, H., 2004. Highly efficient gene replacements in Neurospora strains deficient for non-homologous end joining. Proc. Natl. Acad. Sci. USA 101(33), 12248-53]. M. grisea KU80 deletion mutants were constructed and displayed wild-type phenotypes regarding pathogenicity, growth, sporulation and mating. MgADE4 targeted gene replacement frequency was increased in Deltaku80 mutants (80% vs 5%) and high frequencies (>80%) were observed at seven other loci. However, the deletion of MgKU80 did not increase the frequency of ACE1 replacement indicating that this locus has an intrinsic reduced ability for gene replacement. These results open the way to large-scale reverse genetics experiments in M. grisea facilitating the study of the infection process.

Magnaporthe grisea is responsible for a devastating fungal disease of rice called blast. Current control of this disease relies on resistant rice cultivars that recognize M. grisea signals corresponding to specific secreted proteins encoded by avirulence genes. The M. grisea ACE1 avirulence gene differs from others, since it controls the biosynthesis of a secondary metabolite likely recognized by rice cultivars carrying the Pi33 resistance gene. Using a transcriptional fusion between ACE1 promoter and eGFP , we showed that ACE1 is only expressed in appressoria during fungal penetration into rice and barley leaves, onion skin, and cellophane membranes. ACE1 is almost not expressed in appressoria differentiated on Teflon and Mylar artificial membranes. ACE1 expression is not induced by cellophane and plant cell wall components, demonstrating that it does not require typical host plant compounds. Cyclic AMP (cAMP) signaling mutants Δ cpkA and Δ mac1 sum1 - 99 and tetraspanin mutant Δ pls1 :: hph differentiate melanized appressoria with normal turgor but are unable to penetrate host plant leaves. ACE1 is normally expressed in these mutants, suggesting that it does not require cAMP signaling or a successful penetration event. ACE1 is not expressed in appressoria of the buf1 :: hph mutant defective for melanin biosynthesis and appressorial turgor. The addition of hyperosmotic solutes to buf1 :: hph appressoria restores appressorial development and ACE1 expression. Treatments of young wild-type appressoria with actin and tubulin inhibitors reduce both fungal penetration and ACE1 expression. These experiments suggest that ACE1 appressorium-specific expression does not depend on host plant signals but is connected to the onset of appressorium-mediated penetration.

Plant 4-hydroxyphenylpyruvate dioxygenase (HPPD) is part of the biosynthetic pathway leading to plastoquinone and vitamin E. This enzyme is also the molecular target of various new bleaching herbicides for which genetically engineered tolerant crops are being developed. We have expressed a sensitive bacterial hppd gene from Pseudomonas fluorescens in plastid transformants of tobacco and soybean and characterized in detail the recombinant lines. HPPD accumulates to approximately 5% of total soluble protein in transgenic chloroplasts of both species. As a result, the soybean and tobacco plastid transformants acquire a strong herbicide tolerance, performing better than nuclear transformants. In contrast, the over-expression of HPPD has no significant impact on the vitamin E content of leaves or seeds, quantitatively or qualitatively. A new strategy is presented and exemplified in tobacco which allows the rapid generation of antibiotic marker-free plastid transformants containing the herbicide tolerance gene only. This work reports, for the first time, the plastome engineering for herbicide tolerance in a major agronomic crop, and a technology leading to marker-free lines for this trait.

International audience

Earthworms are important ecosystem engineers, and assessment of the risk of plant protection products toward them is part of the European environmental risk assessment (ERA). In the current ERA scheme, exposure and effects are represented simplistically and are not well integrated, resulting in uncertainty when the results are applied to ecosystems. Modeling offers a powerful tool to integrate the effects observed in lower tier laboratory studies with the environmental conditions under which exposure is expected in the field. This paper provides a summary of the (In)Field Organism Risk modEling by coupling Soil Exposure and Effect (FORESEE) Workshop held 28-30 January 2020 in Düsseldorf, Germany. This workshop focused on toxicokinetic-toxicodynamic (TKTD) and population modeling of earthworms in the context of ERA. The goal was to bring together scientists from different stakeholder groups to discuss the current state of soil invertebrate modeling and to explore how earthworm modeling could be applied to risk assessments, in particular how the different model outputs can be used in the tiered ERA approach. In support of these goals, the workshop aimed at addressing the requirements and concerns of the different stakeholder groups to support further model development. The modeling approach included 4 submodules to cover the most relevant processes for earthworm risk assessment: environment, behavior (feeding, vertical movement), TKTD, and population. Four workgroups examined different aspects of the model with relevance for risk assessment, earthworm ecology, uptake routes, and cross-species extrapolation and model testing. Here, we present the perspectives of each workgroup and highlight how the collaborative effort of participants from multidisciplinary backgrounds helped to establish common ground. In addition, we provide a list of recommendations for how earthworm TKTD modeling could address some of the uncertainties in current risk assessments for plant protection products. Integr Environ Assess Manag 2021;17:352-363. © 2020 SETAC.

Conservation of bacterial consortia: functional and genetic consequences. Conservation of bacterial consortia exhibiting a high functional diversity can be useful to study both genetic and functional diversity as well as to exploit functional capacities for example to study biotransformation of different molecules and to analyze chemicals possibly produced. In order to improve bio-tests based on the use of complex microbial community, the possibility to repeat analyses with bacterial consortia exhibiting similar capacities of transformation over time was necessary. That is why consequences of conservation methods, either -80°C freezing in glycerol or lyophilization were studied. Bacterial consortia were characterized according to quantitative, qualitative and functional criteria: i) bacterial density by direct counting using orange acridine staining, ii) genetic structure by Ribosomal Intergenic Spacer Analysis, iii) respiratory activity by Substrate Induced Respiration measurements and iv) capacity to transform various toxic components in bio-tests. Bacterial consortia were extracted from two soils by mechanical dispersion. Culture of extracted consortia after conservation induced a slight decrease of bacterial density especially when they were lyophilized. Changes in respiratory capacities were also observed depending on soil. Although genetic structure of consortia became close after culture whatever the conservation method, differences in biotransformation capacities were observed depending on the toxic component tested. For atrazine, lyophilization induced a decrease in biotransformation capacity compared with frozen consortia. In conclusion, freezing has been shown to be the conservation method which allowed to minimize changes in transformation capacity in bacterial consortia.

The succession of soybean/maize has been largely adopted. Storm damage and crop problems can lead to grain loss, generating maize ear fragments or even whole ears that remain in the soil and still display germination viability, resulting in the occurrence of volunteer plants. In this context, the present study aimed to evaluate the interference of voluntary maize plants on soybean and investigate the susceptibility of maize hybrids to pre-emergence herbicides. In the first step, an experiment was performed evaluating the influence of voluntary maize plant density and spatial distribution on soybean. The experiment was performed in a randomized completely block design (RCBD) with four replications, with treatments disposed in factorial arrangement (2 x 4) + 1. The first factor corresponded to the spatial distribution of maize plants: row or in between soybean rows; while the second factor adopted four infestation densities of maize plants m-2: 4, 8, 12, and 16. The additional treatment consisted of a control without maize plants. For the second step, an experiment was conducted in two locations aiming to determine the efficacy of pre-emergence herbicides in the control of voluntary maize. Both experiments were installed in RCBD in a split-plot scheme with four replications. Fomesafen, lactofen, sulfentrazone, chlorimuron-ethyl, diclosulam, flumetsulam, imazethapyr, clomazone, metribuzin, [sulfentrazone + diuron], [imazethapyr + flumioxazin], and a control without herbicide application were evaluated in the main plot. In each subplot, the maize hybrids DKB310 PRO3™ and DKB390 PRO3™ were evaluated. No influence on the position of voluntary maize on the soybean yield was observed. The presence of the maize population led to a progressive decrease in soybean yield, ranging up to 86%, at 16 plants m-2. DKB390 displayed a stand reduction of 82.88% after the use of diclosulam. Diclosulam led to better results regarding maize plant decreases for both hybrids. The succession of soybean/maize has been largely adopted. Storm damage and crop problems can lead to grain loss, generating maize ear fragments or even whole ears that remain in the soil and still display germination viability, resulting in the occurrence of volunteer plants. In this context, the present study aimed to evaluate the interference of voluntary maize plants on soybean and investigate the susceptibility of maize hybrids to pre-emergence herbicides. In the first step, an experiment was performed evaluating the influence of voluntary maize plant density and spatial distribution on soybean. The experiment was performed in a randomized completely block design (RCBD) with four replications, with treatments disposed in factorial arrangement (2 x 4) + 1. The first factor corresponded to the spatial distribution of maize plants: row or in between soybean rows; while the second factor adopted four infestation densities of maize plants m-2: 4, 8, 12, and 16. The additional treatment consisted of a control without maize plants. For the second step, an experiment was conducted in two locations aiming to determine the efficacy of pre-emergence herbicides in the control of voluntary maize. Both experiments were installed in RCBD in a split-plot scheme with four replications. Fomesafen, lactofen, sulfentrazone, chlorimuron-ethyl, diclosulam, flumetsulam, imazethapyr, clomazone, metribuzin, [sulfentrazone + diuron], [imazethapyr + flumioxazin], and a control without herbicide application were evaluated in the main plot. In each subplot, the maize hybrids DKB310 PRO3™ and DKB390 PRO3™ were evaluated. No influence on the position of voluntary maize on the soybean yield was observed. The presence of the maize population led to a progressive decrease in soybean yield, ranging up to 86%, at 16 plants m-2. DKB390 displayed a stand reduction of 82.88% after the use of diclosulam. Diclosulam led to better results regarding maize plant decreases for both hybrids.

Introduction The COVID-19 pandemic placed an unprecedented overload on healthcare system globally. With all medical resources being dedicated to contain the spread of the disease, the pandemic may have impacted the burden of other infectious diseases such as dengue, particularly in countries endemic for dengue fever. Indeed, the co‐occurrence of COVID‐19 made dengue diagnosis challenging because of some shared clinical manifestations between the two pathogens. Furthermore, the sudden emergence and novelty of this global public health crisis has forced the suspension or slow-down of several research trials due to the lack of sufficient knowledge on how to handle the continuity of research trials during the pandemic. We report on challenges we have faced during the COVID-19 pandemic and measures that were implemented to continue the iDEM project (intervention for Dengue Epidemiology in Malaysia). Methods This randomized controlled trial aims to assess the effectiveness of Integrated Vector Management (IVM) on the incidence of dengue in urban Malaysia by combining: targeted outdoor residual spraying (TORS), deployment of auto-dissemination devices (ADDs), and active community engagement (CE). Our operational activities started on February 10, 2020, a few weeks before the implementation of non-pharmaceutical interventions to contain the spread of COVID-19 in Malaysia. Results The three main issues affecting the continuity of the trial were: ensuring the safety of field workers during the interventions; ensuring the planned turnover of TORS application and ADD deployment and services; and maintaining the CE activities as far as possible. Conclusions Even though the pandemic has created monumental challenges, we ensured the safety of field workers by providing complete personal protective equipment and regular COVID-19 testing. Albeit with delay, we maintained the planned interval time between TORS application and ADDs services by overlapping the intervention cycles instead of having them in a sequential scheme. CE activities continued remotely through several channels (e.g., phone calls and text messages). Sustained efforts of the management team, significant involvement of the Malaysian Ministry of Health and a quick and smart adaptation of the trial organisation according to the pandemic situation were the main factors that allowed the successful continuation of our research. Trial registration Trial registration number: ISRCTN-81915073. Date of registration: 17/04/2020, 'Retrospectively registered'.

International audience; Growing virus resistant varieties is a highly effective means to avoid yield loss due to infection by many types of virus. The challenge is to be able to detect resistance donors within plant species diversity and then quickly introduce alleles conferring resistance into elite genetic backgrounds. Until now, mainly monogenic forms of resistance with major effects have been introduced in crops. Polygenic resistance is harder to map and introduce in susceptible genetic backgrounds, but it is likely more durable. Genome wide association studies (GWAS) offer an opportunity to accelerate mapping of both monogenic and polygenic resistance, but have seldom been implemented and described in the plant–virus interaction context. Yet, all of the 48 plant–virus GWAS published so far have successfully mapped QTLs involved in plant virus resistance. In this review, we analyzed general and specific GWAS issues regarding plant virus resistance. We have identified and described several key steps throughout the GWAS pipeline, from diversity panel assembly to GWAS result analyses. Based on the 48 published articles, we analyzed the impact of each key step on the GWAS power and showcase several GWAS methods tailored to all types of viruses.

BACKGROUND Management of pesticide resistance is a major issue in modern agricultural systems, particularly in the context of the broader challenge of reducing pesticide use. However, such management must be adapted to resistance dynamics, which remains challenging to predict due to its dependence on many biological traits of pests, interactions with the environment and pesticide use. We retrospectively studied the evolution of reported resistances to four modes of action (benzimidazoles, quinone outside inhibitors, sterol demethylation inhibitors and succinate dehydrogenase inhibitors), in French populations of the wheat pathogen Zymoseptoria tritici. RESULTS We used statistical models to analyse the Performance trial network data set (2004-2017; ∼ 70 locations in France yearly). They highlighted contrasting behaviours between phenotypes, for example: (i) stable spatial distributions and colonization front structures over time, and (ii) different frequency growth rates at the national scale and between regions. CONCLUSION We provide a quantitative description of the spatiotemporal patterns of resistance evolution for fungicides with several modes of action. Moreover, we highlight some unexpected resistance dynamics in France, with major differences between the north and south. This complex pattern of resistance evolution in French populations is consistent with previous descriptions of dynamics at the European scale. These results should make it easier to anticipate evolution locally and to improve the management of resistance. © 2019 Society of Chemical Industry.

A synthesis to access rarely described 3-amino-5-fluoroalkylfurans has been developed by cyclization of easily accessible fluorovinamides. This method is rapid and simple and affords the desired furans as hydrochloride salts in quantitative or nearly quantitative yields. It is compatible with four different fluorinated groups (-CF3, -CF2CF3, -CHF2, and -CF2Cl) and a wide range of substituents on the amine.

Fungi are the most prevalent plant pathogens, causing annually important damages. To infect and colonize their hosts, they secrete effectors including hydrolytic enzymes able to kill and macerate plant tissues. These secreted proteins are transported from the Endoplasmic Reticulum and the Golgi apparatus to the extracellular space through intracellular vesicles. In pathogenic fungi, intracellular vesicles were described but their biogenesis and their role in virulence remain unclear. In this study, we report the essential role of clathrin heavy chain (CHC) in the pathogenicity of Botrytis cinerea, the agent of gray mold disease. To investigate the importance of this protein involved in coat vesicles formation in eukaryotic cells, a T-DNA insertional mutant reduced in the expression of the CHC-encoding gene, and a mutant expressing a dominant-negative form of CHC were studied. Both mutants were strongly affected in pathogenicity. Characterization of the mutants revealed altered infection cushions and an important defect in protein secretion. This study demonstrates the essential role of clathrin in the infectious process of a plant pathogenic fungus and more particularly its role in virulence factors delivery.

This research proposes new perspectives accounting for the uncertainty on 50% effective rates (ER50) as interval input for species sensitivity distribution (SSD) analyses and evaluating how to include this uncertainty may influence the 5% Hazard Rate (HR5) estimation. We explored various endpoints (survival, emergence, shoot-dry-weight) for non-target plants from seven standard greenhouse studies that used different experimental approaches (vegetative vigour vs. seedling emergence) and applied seven herbicides at different growth stages. Firstly, for each endpoint of each study, a three-parameter log-logistic model was fitted to experimental toxicity test data for each species under a Bayesian framework to get a posterior probability distribution for ER50. Then, in order to account for the uncertainty on the ER50, we explored two censoring criteria to automatically censor ER50 taking the ER50 probability distribution and the range of tested rates into account. Secondly, based on dose-response fitting results and censoring criteria, we considered input ER50 values for SSD analyses in three ways (only point estimates chosen as ER50 medians, interval-censored ER50 based on their 95% credible interval and censored ER50 according to one of the two criteria), by fitting a log-normal distribution under a frequentist framework to get the three corresponding HR5 estimates. We observed that SSD fitted reasonably well when there were at least six distinct intervals for the ER50 values. By comparing the three SSD curves and the three HR5 estimates, we shed new light on the fact that both propagating the uncertainty from the ER50 estimates and including censored data into SSD analyses often leads to smaller point estimates of HR5, which is more conservative in a risk assessment context. In addition, we recommend not to focus solely on the point estimate of the HR5, but also to look at the precision of this estimate as depicted by its 95% confidence interval.

The necrotrophic plant-pathogen fungus Botrytis cinerea produces multicellular appressoria dedicated to plant penetration, named infection cushions (IC). A microarray analysis was performed to identify genes upregulated in mature IC. The expression data were validated by RT-qPCR analysis performed in vitro and in planta, proteomic analysis of the IC secretome and biochemical assays. 1231 upregulated genes and 79 up-accumulated proteins were identified. The data support the secretion of effectors by IC: phytotoxins, ROS, proteases, cutinases, plant cell wall-degrading enzymes and plant cell death-inducing proteins. Parallel upregulation of sugar transport and sugar catabolism-encoding genes would indicate a role of IC in nutrition. The data also reveal a substantial remodelling of the IC cell wall and suggest a role for melanin and chitosan in IC function. Lastly, mutagenesis of two upregulated genes in IC identified secreted fasciclin-like proteins as actors in the pathogenesis of B. cinerea. These results support the role of IC in plant penetration and also introduce other unexpected functions for this fungal organ, in colonization, necrotrophy and nutrition of the pathogen.

Background Phakopsora pachyrhizi is a biotrophic fungal pathogen responsible for the Asian soybean rust disease causing important yield losses in tropical and subtropical soybean-producing countries. P. pachyrhizi triggers important transcriptional changes in soybean plants during infection, with several hundreds of genes being either up- or downregulated. Results Based on published transcriptomic data, we identified a predicted chitinase gene, referred to as GmCHIT1, that was upregulated in the first hours of infection. We first confirmed this early induction and showed that this gene was expressed as early as 8 h after P. pachyrhizi inoculation. To investigate the promoter of GmCHIT1, transgenic soybean plants expressing the green fluorescence protein (GFP) under the control of the GmCHIT1 promoter were generated. Following inoculation of these transgenic plants with P. pachyrhizi, GFP fluorescence was detected in a limited area located around appressoria, the fungal penetration structures. Fluorescence was also observed after mechanical wounding whereas no variation in fluorescence of pGmCHIT1:GFP transgenic plants was detected after a treatment with an ethylene precursor or a methyl jasmonate analogue. Conclusion We identified a soybean chitinase promoter exhibiting an early induction by P. pachyrhizi located in the first infected soybean leaf cells. Our results on the induction of GmCHIT1 promoter by P. pachyrhizi contribute to the identification of a new pathogen inducible promoter in soybean and beyond to the development of a strategy for the Asian soybean rust disease control using biotechnological approaches.

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