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UMR 1332 - Equipe OrFE; In the last few years, high-throughput genomics promised to bridge the gap between plant physiology and plant sciences. In addition, high-throughput genotyping technologies facilitate marker-based selection for better performing genotypes. In strawberry, Fragaria vesca was the first reference sequence obtained in the Rosoideae sub-family. This genome has a high level of synteny with genomes of other species of diploid and polyploid Fragaria, but it also provides a reference for species like Rubus and Rosa for functional genomics. Many tools for genetic, genomic and functional analyses were introduced over the last 10 years and these tools are still evolving. For genotyping, many studies have used simple sequence repeats (SSRs) but whole genome sequencing is now a mature technology and facilitates the development of genotyping chips and other genetic approaches such as genome wide association studies (GWAS). Furthermore, microarray-based technologies have been eclipsed by RNA-seq, the high-throughput sequencing of RNA. These new approaches have led to advances in our understanding of the genetically complex octoploid species, and have revolutionized functional genomics. For all genetic and genomic studies, novel material such as complex crosses such as NILs and EMS have appeared in addition to the classical segregating population. With all these tools, strawberry now emerges as a plant model, not only for studying fruit quality but also for deciphering the mechanisms controlling various aspects of plant biology. Selective examples will be described to illustrate the latest research on strawberry and what is coming from other model species.

UMR 1332 - Equipe OrFE; The Axiom® IStraw90 SNP (single nucleotide polymorphism) array was developed to enable high-throughput genotyping in allo-octoploid cultivated strawberry (Fragaria ×ananassa). However, high cost ($ 80-105 sample-1) limits throughput for certain applications. On average the IStraw90 has yielded 50 to 60% usable data points, defined as PHR (Poly High Resolution) and NMH (No Minor Homozygote) marker classes. Thus, an array is needed with a higher percentage of usable data points at a lower cost. We initiated an effort to identify IStraw90 SNP markers that were genetically mapped in one or more strawberry populations from research programs around the world. Seven programs participated in this endeavor. A total of 41,183 SNP probes were submitted to Affymetrix for quality check, 38,506 of which were accommodated on the Axiom® IStraw35 384HT design. In order to assess the performance of the Axiom® IStraw35 384HT array, 384 DNA samples from the University of Florida strawberry breeding program were assayed at a cost of $ 50 per sample, all inclusive. The performance of the array met expectations. More than 87% of markers belonged to the PHR and NMH categories. This array is expected to provide high-quality genome scanning at a more affordable price for strawberry researchers worldwide.

Augmentative releases of parasitoids may be a useful tool for the area-wide management of tephritid pests. The latter are parasitized by many wasp species, though only a few of them are relevant for augmentative biocontrol purposes. To date, nearly all the actual or potential biocontrol agents for such programs are egg or larval Opiinae parasitoids (Hymenoptera: Braconidae). Here, we review the literature published on their habitat and host location behavior, as well as the factors that modulate this behavior, which is assumed to be sequential; parasitoids forage first for the host habitat and then for the host itself. Parasitoids rely on chemical, visual, and mechanical stimuli, often strongly related to their ecology. Behavioral modulation factors include biotic and abiotic factors including learning, climatic conditions and physiological state of the insect. Finally, conclusions and perspectives for future research are briefly highlighted. A detailed knowledge of this behavior may be very useful for selecting the release sites for both inundative/augmentative releases of mass-reared parasitoids and inoculative releases for classical biocontrol.

Fruit flies are pests of economic importance inWest Africa due to their quarantine status and losses recorded in fruits and vegetables. Before the introduction of exotic species of parasitoids against any exotic fruit fly species, it is fundamental to first determine the presence and monitor the native parasitoid species. This work was carried out in Casamance (Senegal), during the rainy season of 2010, with sampling of 5191 fruits from 22 plant species. Seven species of parasitoids (all Braconidae) were recorded and reared from six fruit species. The parasitoids included Fopius caudatus (Szépligeti), F. silvestrii (Wharton), F. desideratus (Bridwell), Diachasmimorpha fullawayi (Silvestri), D. carinata (Szépligeti), Psyttalia cosyrae (Wilkinson) and P. concolor (Szépligeti). The most abundant species was F. caudatus (63.97 %). The overall mean parasitism rate observed in all samples was 2.4 ± 1.3 %. Ceratitis cosyra (Walker) (77 %) was the host fly most commonly reared from fruits yielding parasitoids including F. caudatus. Annona senegalensis Pers. was the fruit species most frequently infested by fruit flies and Saba comorensis (Boj. ex DC) Pichon fruits had the highest parasitism rates. In the current work, there were no parasitoids reared from the recently introduced pest, Bactrocera invadens Drew, Tsuruta and White. This is the first report of all these reared parasitoids, except D. fullawayi, in Senegal.

Publication Inra prise en compte dans l'analyse bibliométrique des publications scientifiques mondiales sur les Fruits, les Légumes et la Pomme de terre. Période 2000-2012. http://prodinra.inra.fr/record/256699; International audience; The aim of this research is to study the effects of salt stress during different stages of development in transgenic tomato plants overexpressing the apple spermidine synthase gene (MdSPDS1) compared to wild type (WT) plants. Under salt treatment (100 and 150 mM NaCl), tomato plants clearly displayed several stress symptoms such as impaired seedling growth, decreased chlorophyll content, reduction in fruit yield and increased electrolyte leakage (EL) in leaves. These changes were more prominent in WT plants compared to MdSPDS1 transgenic plants which accumulate significantly more polyamines, namely spermine and spermidine. The response of ascorbate peroxidase (APX) isoenzymes in tomato leaves under saline conditions was also investigated. The transcript levels of SlApx genes were significantly up regulated under 100 mM NaCl either in wild type or in transgenic plants. Under 150 mM NaCl, only transgenic plants were capable to maintain high expression of SlApx genes, whereas in WT plants the expression declined after one month treatment. As a consequence, APX activity was significantly higher in MdSPDS1 transgenic plants compared to WT under saline conditions. These results suggest that elevated APX activity might contribute largely to the protection against oxidative stress generated by NaCl treatments and thus confer salinity tolerance in tomato overexpressing MdSPDS1.

Plant trypanosomes have never been at the forefront of plant pathology matters. Even today, they hold only a marginal place among plant pathogens. There are two main reasons for this isolation: (1) the diseases caused by trypanosomes are confined to northern Latin America and the southern Caribbean; and (2) they affect only a small number of cultivated plants. It can also be added that the outbreak of one such disease, on coffee in a small country, Suriname (a Dutch colony at the time), became a real problem only during 1930–1950, a time during which the economic effects of World War II were at least as important, if not more important, to the coffee industry, and the publications concerning the outbreak were in German. Finally, because it was impossible at the time to isolate these organisms and culture them in vitro, the scientific community, including plant pathologists and parasitologists, lost interest in them. In this chapter we shall see that plant trypanosomes are of great interest in different respects, including parasitology, the evolution of members of Trypanosomatidae, parasite biology, plant pathology, transmission and insect vectors, and epidemiology.

[EN] Background: Genomic libraries of introgression lines (ILs) consist of collections of homozygous lines with a single chromosomal introgression from a donor genotype in a common, usually elite, genetic background, representing the whole donor genome in the full collection. Currently, the only available melon IL collection was generated using Piel de sapo (var. inodorus) as the recurrent background. ILs are not available in genetic backgrounds representing other important market class cultivars, such as the cantalupensis. The recent availability of genomic tools in melon, such as SNP collections and genetic maps, facilitates the development of such mapping populations. Results: We have developed a new genomic library of introgression lines from the Japanese cv. Ginsen Makuwa (var. makuwa) into the French Charentais-type cv. Vedrantais (var. cantalupensis) genetic background. In order to speed up the breeding program, we applied medium-throughput SNP genotyping with Sequenom MassARRAY technology in early backcross generations and High Resolution Melting in the final steps. The phenotyping of the backcross generations and of the final set of 27 ILs (averaging 1.3 introgressions/plant and covering nearly 100 % of the donor genome), in three environments, allowed the detection of stable QTLs for flowering and fruit quality traits, including some that affect fruit size in chromosomes 6 and 11, others that change fruit shape in chromosomes 7 and 11, others that change flesh color in chromosomes 2, 8 and 9, and still others that increase sucrose content and delay climacteric behavior in chromosomes 5 and 10. Conclusions: A new melon IL collection in the Charentais genetic background has been developed. Genomic regions that consistently affect flowering and fruit quality traits have been identified, which demonstrates the suitability of this collection for dissecting complex traits in melon. Additionally, pre-breeding lines with new, commercially interesting phenotypes have been observed, including delayed climacteric ripening associated to higher sucrose levels, which is of great interest for Charentais cultivar breeding., This work has been carried out in the framework of the Programa de Valorización y Recursos Conjuntos de I + D + i de VLC/CAMPUS and has been funded by the Ministerio de Educación, Cultura y Deporte as part of the Programa Campus de Excelencia Internacional. IL generation, genotyping and phenotyping was supported by SAFQIM project, AGL2012-40130-C02-02 of the Spanish Ministry of Economy and Competitivity (MINECO). The authors also wish to thank the MINECO project AGL2014-53398-C2-2-R, co-funded with FEDER funds.

The coordinated pattern of cell division and cell expansion during fruit set and fruit growth in tomato pericarp. Fruit Structure 2015

UMR BFP - Equipe GFDF; The glycero-3-phosphate acyl transferase GPAT6-like from tomato plays a crucial role in fruitcutin biosynthesis. PaDiBa 2015. International Symposium on Plant Apoplastic Diffusion Barriers

Characterization of the balance between asexual and sexual reproduction in diploid strawberry. Plant Biology Scandinavia 2015, The 26th SPPS Congress

International audience; This study falls within the framework of the industrial exploitation of by-products of the prickly pear (Opuntia ficus-indica). The study aims to evaluate the use of hydro-ethanolic extract of prickly pear peels as a substitute of vitamin E used as antioxidant in margarine preservation. The extract was rich in total phenolics (1512.58 mg GAE/100 g DM). HPLC-DAD-ESI-MSn analyses allowed the identification of sixteen compounds belonging to hydroxybenzoic acids, hydroxycinnamic acids and flavonoids. The extract displayed a reducing power and an antiradical activity that were respectively similar to and lower than the two antioxidant standards quercetin and butylated hydroxyanisole. Tests conducted at laboratory and pilot scales showed that the margarines elaborated with peel extract were more resistant to oxidation than the margarine reference with vitamin E. In addition, neither the physicochemical nor the microbiological properties were modified. Prickly pear peels contain bioactive substances that could be used in different food sectors.

Introduction. Pays d'Afrique de l'Ouest, la Guinee a un climat tropical et un relief accidente, avec un reseau hydrographique important. Elle presente quatre regions naturelles dans lesquelles se developpent spontanement plusieurs especes fruitieres dont les fruits sont actuellement consommes et vendus dans les marches nationaux. Afin de mieux exploiter ces produits, des enquetes ont cherche a constituer une base de donnees fiables identifiant les especes fruitieres impliquees, leurs zones et leurs periodes de production, le circuit de commercialisation des produits, leurs techniques de conservation, de transformation et de consommation. Materiel et methodes. Un suivi des prix des fruits de cueillette commercialises en Guinee et une analyse approfondie de leur production et de leur utilisation ont ete realises de mars 1998 a fevrier 2000 sur deux memes marches guineens. Pour cela, les informations requises (prix, periode, conditionnement, circuit de commercialisation) ont ete collectees par enquetes effectuees tous les quinze jours et consignees sur une fiche specifique. Resultats. L'etude a mis en evidence d'eventuels problemes d'approvisionnement des marches, lies a leur site. Parmi les especes identifiees, douze se sont revelees plus importantes et ont fait l'objet d'analyses. Leurs zones de production ont ete definies. La majorite des fruits commercialises sur les marches enquetes murissent entre mars et juin ; ils representent une source de revenus pour une bonne part de la population. Les techniques de conservation, de commercialisation, de transformation et de consommation ont ete repertoriees. Conclusion. L'enquete effectuee conduit a encourager la protection des fruitiers de cueillette et a conseiller leur introduction progressive dans les vergers familiaux. Les programmes de recherches nationaux cherchent a intervenir egalement dans la transformation et la conservation des produits issus de cueillettes, qui posent de grosses difficultes aux producteurs.

Fruit systems biology. IPMB 2015 - 11. International Congress of Plant Molecular Biology

Validating markers linked to soluble solid contents in octoploid strawberry . 2014 ASHS Annual Conference

Nectarine stem pitting-associated virus (NSPaV) is a recently described member of the genus Luteovirus in the family Luteoviridae on which very limited information is available. Initially described in the United States on post-quarantine imported nectarine (Prunus persica) trees (Bag et al. 2015), it was later detected on peach and nectarine plants from California (Villamor et al. 2016). Although it was initially described as tentatively associated with severe stem-pitting symptoms (Bag et al. 2015), NSPaV association with disease remains uncertain because it has been detected in some symptomless trees (Villamor et al. 2016). During a survey in 2015, five Japanese apricot (P. mume) samples collected in Japan and showing various virus-like symptoms such as discolorations and spotting on their leaves were individually analyzed by Illumina deep sequencing of cDNA libraries prepared from purified double-stranded RNAs (Candresse et al. 2013). Analysis of the sequence data showed that in one sample, collected in a park in Morioka, seven contigs showed high nucleotide identity values (90 to 98%) with the closely related NSPaV sequences available in GenBank (accession nos. KP638562, KT273409, and KT273410). These contigs totaled 3.4 kb or about 68% of NSPaV genome (NC_027211; Bag et al. 2015) and corresponded to about 0.37% of the total sequencing reads obtained for the sample. The presence of NSPaV in the sample was confirmed by RT-PCR using the NSPaV-F mod 5′-AGACTMAAATTCAATGARAAGA-3′ and NSPaV-R 5′-TTTCACAAATGATAACACAAT-3′ primer pair modified from Bag et al. (2015). The expected 460-bp fragment, corresponding to positions 1646 to 2106 of the genome (RdRp gene), was obtained and, upon direct sequencing (KX853093), shown to share 96.2 to 96.7% nucleotide identity with the NSPaV isolates present in GenBank. To the best of our knowledge, this is the first report of NSPaV presence in Japan and in P. mume, extending the information on both its host range and geographical distribution. The analysis of the high-throughput sequence data obtained on the NSPaV-infected sample showed it to be also infected by Asian prunus virus 1 and thus, no clear conclusion can be drawn on whether NSPaV may be responsible for any specific symptoms in P. mume.

International audience; Fleshy fruits are important worldwide crops that are rich sources of useful and functional compounds in the human diet. Although fruit ripening has been extensively studied, early fruit development has not been paid much attention despite its contribution to the sensorial and nutritional quality of the fruit. This study aimed at identifying candidate genes involved in early fleshy fruit development that can contribute to the control of final fruit size and composition by comparative analysis of tomato and grape genes. By mining public sequences and microarray database, we identified 23 transcription factors belonging to 14 classes (AP2-EREBP, ARF, bHLH, bZIP, C2C2-GATA, FHA, GeBP, GRAS, HB, LIM, MYB, PBF-2-like, SBP and WRKY) as candidate regulatory genes for early fruit development. The function of these candidate genes will be confirmed by several reverse genetic approaches using the miniature tomato cv. Micro-Tom.

International audience; Endopolyploidy, i.e. the amplification of genomic DNA without mitosis, is a widespread process in plants. Cells from the tomato fruit pericarp are characterized by a wide range of ploidy levels (from 2C to 256C). Although various functional hypotheses have been attributed to endoreduplication according to the literature, evidence for a specific role of endoreduplication in transcription and metabolism control is still lacking. We have developed a new method based on bacterial artificial chromosome fluorescent in situ hybridization (BAC-FISH) that allows the in situ determination of DNA ploidy levels of individual nuclei. The advantage of this method is illustrated by the analysis of ploidy levels and cell sizes within the pericarp tissue from mature green tomato fruits. Using this cellular approach we established the ploidy map of the pericarp tissue. Based on this map, we performed a structural analysis of endoreduplicated nuclei at the level of chromatin organization, nuclear shape and relationship with mitochondria. We demonstrated a link between the ploidy level of nuclei, the complexity of their shape and the number of mitochondria at the vicinity of polyploid nuclei. The use of the DNA FISH method demonstrated that endopolyploidy leads to the formation of polytene chromosomes, whereas the use of a RNA FISH method demonstrated that the rDNA transcription was increased during polyploidization. Performing quantitative PCR (qPCR) and RT-qPCR on sorted nuclei respectively, we confirmed that endoreduplication did amplified exponentially loci for a set of specific genes allowing us to demonstrade that endoreduplication results in an increasing transcriptional activity.

International audience; Understanding how the fruit microclimate affects ascorbate (AsA) biosynthesis, oxidation and recycling is a great challenge in improving fruit nutritional quality. For this purpose, tomatoes at breaker stage were harvested and placed in controlled environment conditions at different temperatures (12, 17, 23, 27 and 31 °C) and irradiance regimes (darkness or 150 µmol m(-2) s(-1)). Fruit pericarp tissue was used to assay ascorbate, glutathione, enzymes related to oxidative stress and the AsA/glutathione cycle and follow the expression of genes coding for 5 enzymes of the AsA biosynthesis pathway (GME, VTC2, GPP, L-GalDH, GLDH). The AsA pool size in pericarp tissue was significantly higher under light at temperatures below 27 °C. In addition, light promoted glutathione accumulation at low and high temperatures. At 12 °C, increased AsA content was correlated with the enhanced expression of all genes of the biosynthesis pathway studied, combined with higher DHAR and MDHAR activities and increased enzymatic activities related to oxidative stress (CAT and APX). In contrast, at 31 °C, MDHAR and GR activities were significantly reduced under light indicating that enzymes of the AsA/glutathione cycle may limit AsA recycling and pool size in fruit pericarp, despite enhanced expression of genes coding for AsA biosynthesis enzymes. In conclusion, this study confirms the important role of fruit microclimate in the regulation of fruit pericarp AsA content, as under oxidative conditions (12 °C, light) total fruit pericarp AsA content increased up to 71%. Moreover, it reveals that light and temperature interact to regulate both AsA biosynthesis gene expression in tomato fruits and AsA oxidation and recycling.

International audience; Besides being a model for fleshy fruits and Solanaceae species, tomato represents one of the main sources of ascorbate (vitamin C) in human diet in many parts of the world. Ascorbate fulfills various roles in plants due to its antioxidant potential and to its connection with other metabolic pathways e. g. cell wall biosynthesis. Among the functional genomic tools recently developed in tomato, EMS (ethyl methanesulfonate) mutant collections provide an opportunity for identifying allelic series of mutations in target genes by TILLING (Targeting Induced Local Lesions IN Genomes). We describe here the use of tomato EMS mutant collections in the miniature cv. Micro-Tom for the discovery of allelic variants in three ascorbate biosynthetic genes encoding the GDP-D-mannose pyrophosphorylase (GMP), the GDP-D-mannose epimerase (GME) and the GDP-L-galactose phosphorylase (GGP) respectively. We report on the discovery of several missense, truncation and splice junction mutations in these genes affecting plant ascorbate content to various levels, and show that several tomato mutant lines with strongly reduced ascorbate content undergo severe bleaching upon exposure to high light intensity.

chapitre 3; National audience

Publication Inra prise en compte dans l'analyse bibliométrique des publications scientifiques mondiales sur les Fruits, les Légumes et la Pomme de terre. Période 2000-2012. http://prodinra.inra.fr/record/256699; The SlPPC2 phosphoenolpyruvate carboxylase (PEPC; EC 4.1.1.31) gene from tomato (Solanum lycopersicum) is differentially and specifically expressed in expanding tissues of developing tomato fruit. We recently showed that a 1966 bp DNA fragment located upstream of the ATG codon of the SlPPC2 gene (GenBank AJ313434) confers appropriate fruit-specificity in transgenic tomato. In this study, we further investigated the regulation of the SlPPC2 promoter gene by analysing the SlPPC2 cis-regulating region fused to either the firefly luciferase (LUC) or the beta-glucuronidase (GUS) reporter gene, using stable genetic transformation and biolistic transient expression assays in the fruit. Biolistic analyses of 5' SlPPC2 promoter deletions fused to LUC in fruits at the 8th day after anthesis revealed that positive regulatory regions are mostly located in the distal region of the promoter. In addition, a 5' UTR leader intron present in the 1966 bp fragment contributes to the proper temporal regulation of LUC activity during fruit development. Interestingly, the SlPPC2 promoter responds to hormones (ethylene) and metabolites (sugars) regulating fruit growth and metabolism. When tested by transient expression assays, the chimeric promoter: LUC fusion constructs allowed gene expression in both fruit and leaf, suggesting that integration into the chromatin is required for fruit-specificity. These results clearly demonstrate that SlPPC2 gene is under tight transcriptional regulation in the developing fruit and that its promoter can be employed to drive transgene expression specifically during the cell expansion stage of tomato fruit. Taken together, the SlPPC2 promoter offers great potential as a candidate for driving transgene expression specifically in developing tomato fruit from various tomato cultivars.

El trabajo se desarrolló en el período comprendido entre los meses de abril de 1998 a febrero del 2000, en áreas próximas a la ciudad de Iquitos. Se determinó y comparó la tasa de infestación ocasionada por Xylosandrus compactus (Eichhoff) sobre plantones de camu-camu, en vivero y empacados. El estudio se complementó con observaciones sobre la biología y ecología del insecto. X. compactus tiene una elevada tasa de infestación sobre los plantones de camu-camu, existiendo una diferencia significativa entre los tratamientos (Chi quadrado = 35,02; 1 gl.). Se observó una preferencia en el ataque por la parte inferior del tallo, que no es evidente estadísticamente (Chi quadrado = 1.29; 2 gl.). Los niveles de infestación en el vivero están favorecidos por la alta humedad del ambiente, los plantones expuestos al sol fueron los menos atacados.

Metabolomics-based approaches are methods of choice for studying changes in fruit composition induced by environmental or genetic modulation of biochemical pathways in the fruit. Owing to enzyme redundancy and high plasticity of the metabolic network, transgenic alteration of the activity of the enzymes from the central metabolism very often results in only slight modifications of the fruit composition. In order to avoid costly and time-consuming plant analysis, we used a fast and sensitive 1 H-NMR-based metabolomic profiling technique allowing discovery of slight metabolite variations in a large number of samples. Here, we describe the screening of transgenic tomato plants in which two genes from the central metabolism, phosphoenolpyruvate carboxylase (EC.3.4.1.1) and malate synthase (EC 2.3.3.9) were silenced by antisens and RNAi strategy. 1 H-NMR metabolomic profiles of methanol-d4 D 2 O buffer extracts of tomato fruit flesh were acquired and subjected to unsupervised multivariate statistical analysis. 1 H-NMR spectra were binned into variable-size spectral domains, making it possible to get an overall analysis of a large number of resonances, even in the case of uncontrolled variation of the chemical shift. Principal component analysis was used to separate groups of samples and to relate known and unknown metabolites to transgenic events. The screening of 100 samples, from extraction to data mining, took 36 h. Thus, this procedure allows the rapid selection of metabolic phenotypes of interest among about 30 transgenic lines. Key words: Metabolome, GMO, tomato, fruit, 1 H-NMR profiling, screening.

L'article original est publié par The American Society of Plant Biologists; International audience; Activities of 28 enzymes from central carbon metabolism were measured in pericarp tissue of ripe tomato fruits from field trials with an introgression line (IL) population generated by introgressing segments of the genome of the wild relative Solanum pennellii (LA0716) into the modern tomato cultivar Solanum lycopersicum M82. Enzyme activities were determined using a robotized platform in optimized conditions, where the activities largely reflect the level of the corresponding proteins. Two experiments were analyzed from years with markedly different climate conditions. A total of 27 quantitative trait loci were shared in both experiments. Most resulted in increased enzyme activity when a portion of the S. lycopersicum genome was substituted with the corresponding portion of the genome of S. pennellii. This reflects the change in activity between the two parental genotypes. The mode of inheritance was studied in a heterozygote IL population. A similar proportion of quantitative trait loci (approximately 30%) showed additive, recessive, and dominant modes of inheritance, with only 5% showing overdominance. Comparison with the location of putative genes for the corresponding proteins indicates a large role of trans-regulatory mechanisms. These results point to the genetic control of individual enzyme activities being under the control of a complex program that is dominated by a network of trans-acting genes.

Publication Inra prise en compte dans l'analyse bibliométrique des publications scientifiques mondiales sur les Fruits, les Légumes et la Pomme de terre. Période 2000-2012. http://prodinra.inra.fr/record/256699; International audience; The effects of cadmium (Cd) were investigated on growth and metabolite profiling in roots and leaves of tomato (Solanum lycopersicum L., Var. Ibiza F1) plants exposed for 3 and 10 days to various CdCl(2) concentrations (0 - 300 mu M). The aim of this study was to describe metabolite modifications in response to Cd stress and to identify Cd stress markers in the roots and leaves of tomato plants. During the treatment, Cd accumulated significantly in the roots compared to stems and leaves. Plant growth (root, stem and leaf) decreased when Cd concentration increased. The analysis of (1)H-NMR spectra of polar extracts showed clear differences between metabolites amounts (soluble sugars, organic and amino acids) in 30 and 300 mu M Cd-treated plants versus control ones. Among soluble sugars and organic acids, glucose, fructose and citrate contents significantly increased, by a factor 2 to 5 in both leaves and roots of Cd treated plants during the first three days of the treatment and then only in roots. In addition, Cd induced qualitative and quantitative changes in amino acid contents in the roots. Asparagine, glutamine and branched chain amino acids (valine, isoleucine, phenylalanine and tryptophane) significantly accumulated after 10 days of Cd exposure. Asparagine content which increased by 26 fold in the roots of 300 mu M Cd treated plants when compared with control ones, was found to be a good marker for Cd stress. In contrast, few modifications occurred in the leaves in response to Cd, except for tyrosine which content was highly increased (by 10 fold) after three days of treatment with 30 mu M. Taken together, our results show that, the exposure of tomato plants to various Cd concentrations results in significant changes in primary metabolism compounds, especially in the accumulation of some amino and organic acids involved in cellular compartmentation and detoxification of Cd.

Publication Inra prise en compte dans l'analyse bibliométrique des publications scientifiques mondiales sur les Fruits, les Légumes et la Pomme de terre. Période 2000-2012. http://prodinra.inra.fr/record/256699; International audience; Few intraspecific genetic linkage maps have been reported for cultivated tomato, mainly because genetic diversity within Solanum lycopersicum is much less than that between tomato species. Single nucleotide polymorphisms (SNPs), the most abundant source of genomic variation, are the most promising source of polymorphisms for the construction of linkage maps for closely related intraspecific lines. In this study, we developed SNP markers based on expressed sequence tags for the construction of intraspecific linkage maps in tomato. Out of the 5607 SNP positions detected through in silico analysis, 1536 were selected for high-throughput genotyping of two mapping populations derived from crosses between 'Micro-Tom' and either 'Ailsa Craig' or 'M82'. A total of 1137 markers, including 793 out of the 1338 successfully genotyped SNPs, along with 344 simple sequence repeat and intronic polymorphism markers, were mapped onto two linkage maps, which covered 1467.8 and 1422.7 cM, respectively. The SNP markers developed were then screened against cultivated tomato lines in order to estimate the transferability of these SNPs to other breeding materials. The molecular markers and linkage maps represent a milestone in the genomics and genetics, and are the first step toward molecular breeding of cultivated tomato. Information on the DNA markers, linkage maps, and SNP genotypes for these tomato lines is available at http://www.kazusa.or.jp/tomato/.

Enzymes interact to generate metabolic networks. The activities of more than 22 enzymes from central metabolism were profiled during the development of fruit of the modern tomato cultivar Solanum lycopersicum 'M82' and its wild relative Solanum pennellii (LA0716). In S. pennellii, the mature fruit remains green and contains lower sugar and higher organic acid levels. These genotypes are the parents of a widely used near introgression line population. Enzymes were also profiled in a second cultivar, S. lycopersicum 'Moneymaker', for which data sets for the developmental changes of metabolites and transcripts are available. Whereas most enzyme activities declined during fruit development in the modern S. lycopersicum cultivars, they remained high or even increased in S. pennellii, especially enzymes required for organic acid synthesis. The enzyme profiles were sufficiently characteristic to allow stages of development and cultivars and the wild species to be distinguished by principal component analysis and clustering. Many enzymes showed coordinated changes during fruit development of a given genotype. Comparison of the correlation matrices revealed a large overlap between the two modern cultivars and considerable overlap with S. pennellii, indicating that despite the very different development responses, some basic modules are retained. Comparison of enzyme activity, metabolite profiles, and transcript profiles in S. lycopersicum 'Moneymaker' revealed remarkably little connectivity between the developmental changes of transcripts and enzymes and even less between enzymes and metabolites. We discuss the concept that the metabolite profile is an emergent property that is generated by complex network interactions. Fil: Steinhauser, Marie Caroline. Max Planck Institute of Molecular Plant Physiology; Alemania Fil: Steinhauser, Dirk. Max Planck Institute of Molecular Plant Physiology; Alemania Fil: Koehl, Karin. Max Planck Institute of Molecular Plant Physiology; Alemania Fil: Carrari, Fernando Oscar. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Gibon, Yves. Max Planck Institute of Molecular Plant Physiology; Alemania Fil: Fernie, Alisdair R.. Max Planck Institute of Molecular Plant Physiology; Alemania Fil: Stitt, Mark. Max Planck Institute of Molecular Plant Physiology; Alemania

Depuis la fin de la décennie 80, la cacaoculture camerounaise est caractérisée par le faible niveau de revenu des producteurs en raison, entre autre, d'une faible productivité du verger cacaoyer. Le faible niveau d'adoption des acquis de la recherche cacaoyère est également en cause d'autant que les technologies développées ne répondent qu'en partie aux besoins réels des producteurs. Dans un contexte marqué par l'embellie des prix du cacao sur le marché international depuis 2000, les producteurs se mobilisent pour relancer la cacaoculture. L'accent est mis notamment sur la diversification des sources de revenus à travers le développement de systèmes de culture plurispécifiques originaux mais dont les rendements restent faibles. Ce guide a pour objectif d'apporter une contribution à l'accompagnement des producteurs dans leur processus de construction d'innovations en cacaoculture. Il s'appuie sur les résultats d'expérimentations pilotes conduites depuis 2005 dans 168 parcelles de cinq villages du Cameroun. il est également destiné à aider les décideurs de projets et les techniciens de l'agriculture et du développement dans leurs prises de décisions

absent

L'efficacité du GF-120 (Dow Chemical), dont l'insecticide est le spinosad, a été évaluée dans le cadre de la lutte contre les mouches des fruits (Diptera: Tephritidae) inféodées au manguier en comparant les résultats de 6 vergers traités par rapport à ceux de 6 vergers témoins très proches des précédents et comportant les mêmes cultivars. Les traitements par taches (un m² / arbre) avec le GF-120 ont été effectués de façon hebdomadaire durant 9 semaines en 2006 et 12 semaines en 2007. Douze vergers de manguiers, Mangifera indica L., situés dans six villages (deux vergers par village: l'un traité et l'autre témoin) tous localisés dans le Borgou (Bénin) ont été suivis toutes les semaines par un piégeage de détection et avec un échantillonnage de fruits afin de détecter le taux d'infestation larvaire par les mouches des fruits. Les deux périodes d'échantillonnage se situaient au début et au milieu du mois de mai en 2006 comme en 2007. Les deux principales espèces de mouches des fruits sont Ceratitis cosyra (Walker) et Bactrocera invadens Drew Tsuruta and White, une espèce exotique qui a très rapidement envahi toute l'Afrique de l'Ouest. Durant les campagnes 2006 et 2007, C. cosyra avait un pic de population précoce (en saison sèche) et les différences (nombre de mouches / piège / semaine) n'ont été significatives, entre vergers traits et témoins, qu'en 2007. Les populations de B. invadens ont augmenté très rapidement après les premières pluies utiles (à partir de début mai) et il n'y avait pas de différences significatives entre vergers traités et témoins. En 2006 et 2007, l'infestation larvaire des fruits par B. invadens était significativement plus faible dans les vergers traités avec le GF-120 que dans les vergers témoins. Les traitements avec le GF-120 ont apporté une réduction de 81 % au niveau du nombre de pupes par kg de fruit frais suivant chaque application hebdomadaire durant 9 semaines en 2006 et une réduction de 89% durant 12 semaines en 2007. La possibilité du couplage de ces traitements par taches avec d'autres méthodes de lutte est discutée. (Texte intégral)

National audience

L’étude comparative du processus de la fécondation chez 3 clones aspermes de clémentinier (Citrus reticulata Blanco) par l’observation de la croissance des tubes polliniques in vivo, a permis de confirmer l’existence d’anomalies, non pas au niveau des relations stigmate-pollen, mais au niveau des relations style-tubes polliniques, laissant supposer la présence d’un système d’auto-incompatibilité pollinique de type gamétophytique. L’arrêt des tubes polliniques, rendus visibles par la microscopie en fluoresence, intervient généralement dès le premier tiers du style, bien que certains d’entre eux parviennent jusque dans les tissus ovariens. Ceci permet d’attribuer un caractère partiel au phénomène mis en cause. De plus l’appréciation, par le biais d’un indice, de la compatibilité intra- et intervariétale des quelques cultivars étudiés laisse apparaître des degrés variables d’affinités., Since seedless clementine (Citrus reticulata Blanco) is supposed not to have a normal fertilization process 3 varieties were studied in regard to the type of incompatibility and their ability in intercrosses. A comparison was first made between seedless SRA 85 clementine and seeded Wilking mandarin: pollen germination on stigmata (fig 1), rate of pollen tube growth and tube evolution in the styles (fig 2) were studied using fluorescent microscopy. It was shown clearly for autofertilized SRA 85 that pollen tubes were stopped by callose in the first third of style (fig 3). Crosses between 3 varieties, Corsica 2, Oroval, SRA 85 were then examined and very limited affinity for each other (fig 8). Estimation of affinity was made by a calculated index (IPC) for each cross. Main IPC values were under a quarter of the optimal index reached for a simulated total compatible cross. It was concluded that the normal fertilization process cannot take place in the seedless clementine because of a gametophytic incompatibility. Nevertheless, it is only partial; some flowers can be fertilized with success at a certain stage, to be defined by further studies.

International audience

International audience