Presence of wild and managed bees in the agricultural crops: Overview of available data to reduce pesticide risk

In France, a derogation to pesticide regulation allows spraying on blooms with insecticides or acaricides bearing the bee label (mention « Abeilles »), but only when no bees are foraging on crops. Nevertheless, no decision rule is available for farmers to assess bees’ absence on the crop. To fill this gap, the Ministry of Agriculture initiated a reflection about environmental and climatic factors influencing the presence of forager bees. This review takes an inventory of data available about foraging activity according to environment or weather. Decision rules based on such criteria appear inappropriate. Only nocturnal sprays of pesticides on crops significantly reduce the risk of bees’ exposure to chemicals.Fil: Decourtye, Axel. Institut National de la Recherche Agronomique; FranciaFil: Vidau, Cyril. Institut National de la Recherche Agronomique; FranciaFil: Rollin, Orianne. Institut National de la Recherche Agronomique; Francia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Requier, Fabrice. Institut National de la Recherche Agronomique; FranciaFil: Rüger, Charlotte. Institut National de la Recherche Agronomique; FranciaFil: Allier, Fabrice. Institut National de la Recherche Agronomique; FranciaFil: Le Féon, Violette Alice Marie. Institut National de la Recherche Agronomique; FranciaFil: Kretzschmar, André. Institut National de la Recherche Agronomique; FranciaFil: Devillers, James. Institut National de la Recherche Agronomique; FranciaFil: Henry, Mickaël. Institut National de la Recherche Agronomique; FranciaFil: Odoux, Jean François. Institut National de la Recherche Agronomique; Franci

Genomic analysis of the necrotrophic fungal pathogens Sclerotinia sclerotiorum and Botrytis cinerea

Sclerotinia sclerotiorum and Botrytis cinerea are closely related necrotrophic plant pathogenic fungi notable for their wide host ranges and environmental persistence. These attributes have made these species models for understanding the complexity of necrotrophic, broad host-range pathogenicity. Despite their similarities, the two species differ in mating behaviour and the ability to produce asexual spores. We have sequenced the genomes of one strain of S. sclerotiorum and two strains of B. cinerea. The comparative analysis of these genomes relative to one another and to other sequenced fungal genomes is provided here. Their 38–39 Mb genomes include 11,860–14,270 predicted genes, which share 83% amino acid identity on average between the two species. We have mapped the S. sclerotiorum assembly to 16 chromosomes and found large-scale co-linearity with the B. cinerea genomes. Seven percent of the S. sclerotiorum genome comprises transposable elements compared to <1% of B. cinerea. The arsenal of genes associated with necrotrophic processes is similar between the species, including genes involved in plant cell wall degradation and oxalic acid production. Analysis of secondary metabolism gene clusters revealed an expansion in number and diversity of B. cinerea–specific secondary metabolites relative to S. sclerotiorum. The potential diversity in secondary metabolism might be involved in adaptation to specific ecological niches. Comparative genome analysis revealed the basis of differing sexual mating compatibility systems between S. sclerotiorum and B. cinerea. The organization of the mating-type loci differs, and their structures provide evidence for the evolution of heterothallism from homothallism. These data shed light on the evolutionary and mechanistic bases of the genetically complex traits of necrotrophic pathogenicity and sexual mating. This resource should facilitate the functional studies designed to better understand what makes these fungi such successful and persistent pathogens of agronomic crops.Fil: Ten Have, Arjen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigaciones Biológicas; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Biológicas; ArgentinaFil: Amselem, Joelle. Institut National de la Recherche Agronomique; FranciaFil: Cuomo, Christina A.. Broad Institute of MIT and Harvard; Estados UnidosFil: Jan, A. L. van Kan. Wageningen University; Países BajosFil: Viaud, Muriel. Institut National de la Recherche Agronomique; FranciaFil: Benito, Ernesto P.. Universidad de Salamanca; EspañaFil: Couloux, Arnaud. Centre National de Séquençage. Genoscope; FranciaFil: Coutinho, Pedro M.. Centre National de la Recherche Scientifique; FranciaFil: Vries, Ronald P. de. Microbiology and Kluyver Centre for Genomics of Industrial Fermentations; Países Bajos. Fungal Biodiversity Centre; Países BajosFil: Dyer, Paul S.. The University Of Nottingham; Reino UnidoFil: Fillinger, Sabine. Institut National de la Recherche Agronomique; FranciaFil: Fournier, Elisabeth. Institut National de la Recherche Agronomique; Francia. Centre de coopération internationale en recherche agronomique pour le développement; FranciaFil: Gout, Lilian. Institut National de la Recherche Agronomique; FranciaFil: Hahn, Matthias. University Of Kaiserlautern; AlemaniaFil: Kohn, Linda. University Of Toronto; CanadáFil: Lapalu, Nicolas. Institut National de la Recherche Agronomique; FranciaFil: Plummer, Kim M.. la Trobe University; AustraliaFil: Pradier, Jean-Marc. Institut National de la Recherche Agronomique; FranciaFil: Quévillon, Emmanuel. Institut National de la Recherche Agronomique; Francia. Centre National de la Recherche Scientifique; FranciaFil: Sharon, Amir. Tel Aviv University. Department of Molecular Biology and Ecology of Plants; IsraelFil: Simon, Adeline. Institut National de la Recherche Agronomique; FranciaFil: Tudzynski, Bettina. Institut für Biologie und Biotechnologie der Pflanzen; AlemaniaFil: Tudzynski, Paul. Institut für Biologie und Biotechnologie der Pflanzen; AlemaniaFil: Wincker, Patrick. Centre National de Séquençage. Genoscope; FranciaFil: Andrew, Marion. University Of Toronto; CanadáFil: Anthouard, Véronique. Centre National de Séquençage. Genoscope; FranciaFil: Beever, Ross E.. Landcare Research; Nueva ZelandaFil: Beffa, Rolland. Centre National de la Recherche Scientifique; FranciaFil: Benoit, Isabelle . Microbiology and Kluyver Centre for Genomics of Industrial Fermentations; Países BajosFil: Bouzid, Ourdia. Microbiology and Kluyver Centre for Genomics of Industrial Fermentations; Países Bajo

Mating-induced transient inhibition of responses to sex pheromone in a male moth is not mediated by octopamine or serotonin

In the male moth, Agrotis ipsilon, mating induces a transient inhibition of behavioural and central nervous responses to sex pheromone. Newly mated males are not attracted to sex pheromone, and the sensitivity of their antennal lobe (AL) neurons is lower than in virgin males. This rapid transient olfactory inhibition prevents them from re-mating unsuccessfully until they have refilled their sex glands. We hypothesized that this olfactory ‘switch off’ might be controlled by neuromodulators such as biogenic amines. To test our hypothesis, we studied the effects of octopamine (OA) and serotonin (5-hydroxytryptamine, 5-HT) on the coding properties of pheromone-sensitive AL neurons in virgin and newly mated males. We show that AL neuron sensitivity increased in newly mated males after injection of OA or 5-HT, but only OA treatment affected certain response characteristics of AL neurons in virgin males. Whereas all measured AL neuron response characteristics were different between virgin and newly mated males, amine treatment in newly mated males restored only the latency and spike frequency, but not the duration of excitatory and inhibitory phases, which were initially found in virgin males. Additionally, we investigated the behavioural effects of OA and 5-HT treatments in virgin and mated males. Although OA and 5-HT enhanced the general flight activity of newly mated males, amine treatments did not restore the behavioural pheromone response of mated moths. Altogether, these results show that, although biogenic amines modulate the olfactory system in moths, OA and 5-HT are probably not involved in the post-mating inhibition of responses to sex pheromone in A. ipsilon males.Fil: Barrozo, Romina. Institut National de la Recherche Agronomique; Francia. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Jarriault, David. Institut National de la Recherche Agronomique; FranciaFil: Simeone, Xenia. Institut National de la Recherche Agronomique; FranciaFil: Gaertner, Cyril. Institut National de la Recherche Agronomique; FranciaFil: Gadenne, Christophe. Institut National de la Recherche Agronomique; FranciaFil: Anton, Sylvia. Institut National de la Recherche Agronomique; Franci

New insights about phenotypic heterogeneity within Propionibacterium freudenreichii argue against its division into subspecies

Propionibacterium freudenreichii is widely used in Swiss-type cheese manufacture, where it contributes to flavour and eye development. It is currently divided into two subspecies, according to the phenotype for lactose fermentation and nitrate reduction (lac+/nit- and lac-/nit+ for P. freudenreichii subsp. shermanii and subsp. freudenreichii, respectively). However, the existence of unclassifiable strains (lac+/nit+ and lac-/nit-) has also been reported. The aim of this study was to revisit the relevance of the subdivision of P. freudenreichii into subspecies, by confirming the existence of unclassifiable strains. Relevant conditions to test the ability of P. freudenreichii for lactose fermentation and nitrate reduction were first determined, by using 10 sequenced strains, in which the presence or absence of the lactose and nitrate genomic islands were known. We also determined whether the subdivision based on lac/nit phenotype was related to other phenotypic properties of interest in cheese manufacture, in this case, the production of aroma compounds, analysed by gas chromatography-mass spectrometry, for a total of 28 strains. The results showed that a too short incubation time can lead to false negative for lactose fermentation and nitrate reduction. They confirmed the existence of four lac/nit phenotypes instead of the two expected, thus leading to 13 unclassifiable strains out of the 28 characterized (7 lac+/nit+ and 6 lac-/nit-). The production of the 15 aroma compounds detected in all cultures varied more within a lac/nit phenotype (up to 20 times) than between them. Taken together, these results demonstrate that the division of P. freudenreichii into two subspecies does not appear to be relevant.Fil: de Freitas, Rosangela. Universidade Federal de Viçosa. Departamento de Tecnologia de Alimentos; Brasil. Institut National de la Recherche Agronomique; Francia. Science et Technologie du Lait et de l; FranciaFil: Madec, Marie Noelle. Institut National de la Recherche Agronomique; Francia. Science et Technologie du Lait et de l; FranciaFil: Chuat, Victoria. Institut National de la Recherche Agronomique; Francia. Science et Technologie du Lait et de l; FranciaFil: Maillard, Marie Bernadette. Institut National de la Recherche Agronomique; Francia. Science et Technologie du Lait et de l; FranciaFil: Abeijon Mukdsi, Maria Claudia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Centro de Referencia para Lactobacilos (i); Argentina. Institut National de la Recherche Agronomique; Francia. Science et Technologie du Lait et de l; FranciaFil: Falentin, Hélène. Institut National de la Recherche Agronomique; Francia. Science et Technologie du Lait et de l; FranciaFil: Carvalho, Antonio Fernandes de. Universidade Federal de Viçosa. Departamento de Tecnologia de Alimentos; BrasilFil: Valence, Florence. Institut National de la Recherche Agronomique; Francia. Science et Technologie du Lait et de l; FranciaFil: Thierry, Anne. Institut National de la Recherche Agronomique; Francia. Science et Technologie du Lait et de l; Franci

Phylogenomic analysis of lactobacillus curvatus reveals two lineages distinguished by genes for fermenting plant-derived carbohydrates

Lactobacillus curvatus is a lactic acid bacterium encountered in many different types of fermented food (meat, seafood, vegetables, and cereals). Although this species plays an important role in the preservation of these foods, few attempts have been made to assess its genomic diversity. This study uses comparative analyses of 13 published genomes (complete or draft) to better understand the evolutionary processes acting on the genome of this species. Phylogenomic analysis, based on a coalescent model of evolution, revealed that the 6,742 sites of single nucleotide polymorphism within the L. curvatus core genome delineate two major groups, with lineage 1 represented by the newly sequenced strain FLEC03, and lineage 2 represented by the type-strain DSM20019. The two lineages could also be distinguished by the content of their accessory genome, which sheds light on a long-term evolutionary process of lineage-dependent genetic acquisition and the possibility of population structure. Interestingly, one clade from lineage 2 shared more accessory genes with strains of lineage 1 than with other strains of lineage 2, indicating recent convergence in carbohydrate catabolism. Both lineages had a wide repertoire of accessory genes involved in the fermentation of plant-derived carbohydrates that are released from polymers of α/β-glucans, α/β-fructans, and N-acetylglucosan. Other gene clusters were distributed among strains according to the type of food from which the strains were isolated. These results give new insight into the ecological niches in which L. curvatus may naturally thrive (such as silage or compost heaps) in addition to fermented food.Fil: Teran, Lucrecia Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Coeuret, Gwendoline. Institut National de la Recherche Agronomique; FranciaFil: Raya, Raul Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Zagorec, Monique. Institut National de la Recherche Agronomique; FranciaFil: Champomier-Vergès, Marie-Christine. Institut National de la Recherche Agronomique; FranciaFil: Chaillou, Stéphane. Institut National de la Recherche Agronomique; Franci

Genetic variation of xylem hydraulic properties shows that wood density is involved in adaptation to drought in Douglas-fir (Pseudotsuga menziesii (Mirb.))

Relationships between wood density and hydraulic efficiency and safety (hydraulic specific conductivity and vulnerability to cavitation, respectively) could clarify the physiological process explaining the impact of density on fitness. We have used new, relatively high-throughput phenotyping methods to estimate genetic variation of wood hydraulic specific conductivity (ks) and vulnerability to cavitation (VC) as an important step toward demonstrating the adaptive value of wood density.Estación Experimental Agropecuaria BarilocheFil: Dalla Salda, Guillermina. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche. Área de Recursos Forestales. Grupo de Ecología Forestal; ArgentinaFil: Martinez Meier, Alejandro. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche. Área de Recursos Forestales. Grupo de Ecología Forestal; ArgentinaFil: Cochard, Hervé. Institut National de la Recherche Agronomique (INRA); FranciaFil: Rozenberg, Philippe. Institut National de la Recherche Agronomique (INRA); Franci

The small secreted effector protein MiSSP7.6 of Laccaria bicolor is required for the establishment of ectomycorrhizal symbiosis

To establish and maintain a symbiotic relationship, the ectomycorrhizal fungus Laccaria bicolor releases mycorrhiza-induced small secreted proteins (MiSSPs) into host roots. Here, we have functionally characterized the MYCORRHIZA-iNDUCED SMALL SECRETED PROTEIN OF 7.6 kDa (MiSSP7.6) from L. bicolor by assessing its induced expression in ectomycorrhizae, silencing its expression by RNAi, and tracking in planta subcellular localization of its protein product. We also carried out yeast two-hybrid assays and bimolecular fluorescence complementation analysis to identify possible protein targets of the MiSSP7.6 effector in Populus roots. We showed that MiSSP7.6 expression is upregulated in ectomycorrhizal rootlets and associated extramatrical mycelium during the late stage of symbiosis development. RNAi mutants with a decreased MiSSP7.6 expression have a lower mycorrhization rate, suggesting a key role in the establishment of the symbiosis with plants. MiSSP7.6 is secreted, and it localizes both to the nuclei and cytoplasm in plant cells. MiSSP7.6 protein was shown to interact with two Populus Trihelix transcription factors. Furthermore, when coexpressed with one of the Trihelix transcription factors, MiSSP7.6 is localized to plant nuclei only. Our data suggest that MiSSP7.6 is a novel secreted symbiotic effector and is a potential determinant for ectomycorrhiza formation.Fil: Kang, Heng. Institut National de la Recherche Agronomique; FranciaFil: Chen, Xin. Institut National de la Recherche Agronomique; FranciaFil: Kemppainen, Minna Johanna. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnologia. Instituto de Microbiologia Basica y Aplicada. Laboratorio de Micologia Molecular.; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Pardo, Alejandro Guillermo. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnologia. Instituto de Microbiologia Basica y Aplicada. Laboratorio de Micologia Molecular.; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Veneault Fourrey, Claire. Institut National de la Recherche Agronomique; FranciaFil: Kohler, Annegret. Institut National de la Recherche Agronomique; FranciaFil: Martin, Francis M.. Institut National de la Recherche Agronomique; Franci

The small secreted effector protein MiSSP7.6 of Laccaria bicolor is required for the establishment of ectomycorrhizal symbiosis

To establish and maintain a symbiotic relationship, the ectomycorrhizal fungus Laccaria bicolor releases mycorrhiza-induced small secreted proteins (MiSSPs) into host roots. Here, we have functionally characterized the MYCORRHIZA-iNDUCED SMALL SECRETED PROTEIN OF 7.6 kDa (MiSSP7.6) from L. bicolor by assessing its induced expression in ectomycorrhizae, silencing its expression by RNAi, and tracking in planta subcellular localization of its protein product. We also carried out yeast two-hybrid assays and bimolecular fluorescence complementation analysis to identify possible protein targets of the MiSSP7.6 effector in Populus roots. We showed that MiSSP7.6 expression is upregulated in ectomycorrhizal rootlets and associated extramatrical mycelium during the late stage of symbiosis development. RNAi mutants with a decreased MiSSP7.6 expression have a lower mycorrhization rate, suggesting a key role in the establishment of the symbiosis with plants. MiSSP7.6 is secreted, and it localizes both to the nuclei and cytoplasm in plant cells. MiSSP7.6 protein was shown to interact with two Populus Trihelix transcription factors. Furthermore, when coexpressed with one of the Trihelix transcription factors, MiSSP7.6 is localized to plant nuclei only. Our data suggest that MiSSP7.6 is a novel secreted symbiotic effector and is a potential determinant for ectomycorrhiza formation.Fil: Kang, Heng. Institut National de la Recherche Agronomique; FranciaFil: Chen, Xin. Institut National de la Recherche Agronomique; FranciaFil: Kemppainen, Minna Johanna. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnologia. Instituto de Microbiologia Basica y Aplicada. Laboratorio de Micologia Molecular.; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Pardo, Alejandro Guillermo. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnologia. Instituto de Microbiologia Basica y Aplicada. Laboratorio de Micologia Molecular.; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Veneault Fourrey, Claire. Institut National de la Recherche Agronomique; FranciaFil: Kohler, Annegret. Institut National de la Recherche Agronomique; FranciaFil: Martin, Francis M.. Institut National de la Recherche Agronomique; Franci

Editorial

The Institut National de la Recherche Agronomique (INRA) was honoured to welcome scientists from all over the world who attended the International Workshop on major Genes and QTL in Sheep and Goats. Approximately 100 participants from 16 countries were registered, contributing 52 oral or poster presentations

An empirical model that uses light attenuation and plant nitrogen status to predict within-canopy N distribution and upscale photosynthesis from leaf to whole canopy

Modelling the spatial and temporal distribution of leaf nitrogen (N) is central to specify photosynthetic parameters and simulate canopy photosynthesis. Leaf photosynthetic parameters depend on both local light availability and whole-plant N status. The interaction between these two levels of integration has generally been modelled by assuming optimal canopy functioning, which is not supported by experiments. During this study, we examined how a set of empirical relationships with measurable parameters could be used instead to predict photosynthesis at the leaf and whole-canopy levels. The distribution of leaf N per unit area (Na) within the canopy was related to leaf light irradiance and to the nitrogen nutrition index (NNI), a whole-plant variable accounting for plant N status. Na was then used to determine the photosynthetic parameters of a leaf gas exchange model. The model was assessed on alfalfa canopies under contrasting N nutrition and with N2-fixing and non-fixing plants. Three experiments were carried out to parameterize the relationships between Na, leaf irradiance, NNI and photosynthetic parameters. An additional independent data set was used for model evaluation. The N distribution model showed that it was able to predict leaf N on the set of leaves tested. The Na at the top of the canopy appeared to be related linearly to the NNI, whereas the coef- ficient accounting for N allocation remained constant. Photosynthetic parameters were related linearly to Na irrespective of N nutrition and the N acquisition mode. Daily patterns of gas exchange were simulated accurately at the leaf scale. When integrated at the whole-canopy scale, the model predicted that raising N availability above an NNI of 1 did not result in increased net photosynthesis. Overall, the model proposed offered a solution for a dynamic coupling of leaf photosynthesis and canopy N distribution without requiring any optimal functioning hypothesis.Fil: Louarn, Gaëtan. Institut National de la Recherche Agronomique; FranciaFil: Frak, Ela. Institut National de la Recherche Agronomique; FranciaFil: Zaka, Serge. Institut National de la Recherche Agronomique; FranciaFil: Lebon, Eric. Institut National de la Recherche Agronomique. Unité Mixte de Recherche; FranciaFil: Prieto, Jorge Alejandro. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza; Argentin