Project description:Sunflower (Helianthus annuus L.) is the third most important source of edible vegetable oil worldwide, and the second most planted oilseed crop in Argentina after soybean. The sunflower breeding program at the Instituto Nacional de Tecnología Agropecuaria (INTA) produced the first Argentinean varieties with the introduction of early materials from Russia, Canada, and Romania, as well as through introgression with wild Helianthus species. This project comprises the SNP variants used to build a custom oligo pool assay used in the frame of the sunflower breeding program for biotic and abiotic stress resistance.
Project description:Background: Respiratory allergy triggered by pollen allergens is increasing at an alarming rate worldwide. Sunflower pollen is thought to be an important source of inhalant allergens. Present study aims to identify the prevalence of sunflower pollinosis among the Indian allergic population and characterizes the pollen allergens using immuno-proteomic tools. Methodology: Clinico-immunological tests were performed to understand the prevalence of sensitivity towards sunflower pollen among the atopic population. Sera from selected sunflower positive patients were used as probe to detect the IgE-reactive proteins from the one and two dimensionally separated proteome of sunflower pollen. The antigenic nature of the sugar moiety of the glycoprotein allergens was studied by meta-periodate modification of IgE-immunoblot. Finally, these allergens were identified by mass-spectrometry (MALDI TOF/TOF and LC ESI qTOF). MASCOT searching was performed against NCBInr database. However, Helianthus annuus genome is not fully sequenced and partially annotated. So in case of low confidence (p> 0.05) protein identification, searching was performed against EST library of Helianthus annuus. Results: Prevalence of sunflower pollen allergy was observed among 21% of the atopic population and associated with elevated level of specific IgE and histamine in the sera of these patients. Immunoscreening of sunflower pollen proteome with patient serum detected seven IgE-reactive proteins with varying molecular weight and pI. Hierarchical clustering of 2D-immunoblot data highlighted three allergens characterized by a more frequent immuno-reactivity and increased levels of IgE antibodies in the sera of susceptible patients. These allergens were considered as the major allergens of sunflower pollen and were found to have their glycan moiety critical for inducing IgE response. Homology driven search of MS/MS data of these IgE-reactive proteins identified seven previously unreported allergens from sunflower pollen. Three major allergenic proteins were identified as two non-isoformic pectate lyases and a cystein protease. Conclusion: Novelty of the present report is the identification of a panel of seven sunflower pollen allergens for the first time at immuno-biochemical and proteomic level, which substantiated the clinical evidence of sunflower allergy. Further purification and recombinant expression of these allergens will improve component-resolved diagnosis and therapy of pollen allergy.
Project description:affy_tour_2010_21 - affy_tour_2010_21 - The aim of this project is to assess the possibility of implementing transcriptomic studies on sunflower plants grown in field assays. Data obtained from plants under drought in the glasshouse have already obtained. We intend to use these results as a template and see if the field offers the possibility of carrying these studies. In order to do so, treatment-effect as well as intra and inter-plot variability will be assessed.-Plants were grown in the field. The assay was arranged in plots with one genotype per plot. The assay was divided in two identically seized parts, containing the same number of plots. Starting from the capitule, flower # -3 was harvested in every plant. In some cases, several plants from the same plot were harvested. In other, plants from different plots were harvested. We expect that this sampling will allow us to assess intra- as well as inter-plot variability in the analysis of drought-driven gene expression modulation. 24 arrays - SUNFLOWER; treated vs untreated comparison
Project description:Microarray-based gene expression analysis of peripheral whole blood is a common strategy in the development of clinically relevant biomarker panels for a variety of human diseases. However, the results of such an analysis are often plagued by decreased sensitivity and reliability due to the effects of relatively high levels of globin mRNA in whole blood. Globin reduction assays have been shown to overcome such effects, but they require large amounts of total RNA and may induce distinct gene expression profiles. The Illumina whole-genome DASL (WG-DASL) assay can detect gene expression levels using partially degraded RNA samples and has the potential to detect rare transcripts present in highly heterogeneous whole blood samples without the need for globin reduction. We therefore assessed the utility of the WG-DASL assay in the analysis of peripheral whole blood gene expression profiles. We find that gene expression detection is significantly increased with the use of WG-DASL compared to the standard in vitro transcription-based direct hybridization (IVT), while globin-probe-negative WG-DASL did not exhibit significant improvements over globin-probe-positive WG-DASL. Globin reduction increases the detection sensitivity and reliability of both WG-DASL and IVT with little effect on raw intensity correlations: raw intensity correlations between total RNA and globin-reduced RNA were 0.970 for IVT and 0.981 for WG-DASL. Overall, the detection sensitivity of the WG-DASL assay is higher than the IVT-based direct hybridization assay, with or without globin reduction, and should be considered in conjunction with globin reduction methods for future blood-based gene expression studies. Peripheral whole blood samples were collected from eight human donors in PAXGene tubes. RNA was isolated after freezing and storage, and then prepared for gene expression analysis using the Illumina Human-Ref8 v3.0 BeadChip. Alpha and beta globin were reduced from a portion of the total RNA using the GLOBINclear assay (Ambion, Austin, TX, USA). Two methods of microarray target preparation were examined: Illumina IVT-based direct hybridization (IVT) and Illumina Whole-Genome DASL (WG-DASL). Two DASL Assay Oligo pools (DAP) were utilized for DASL target preparation: the DASL Assay Oligo Pool with globin probes (DAP +) and the DASL Asssay Oligo Pool without globin probes (DAP-).
Project description:Abiotic stress and more specifically drought is the major limiting factor for sunflower production. ABA is a key hormone for drought stress response in plants and sunflower. This experiment aims at identifying ABA responsive pathways in order to better understand sunflower responses to drought. We studied in parallel microRNA profiles on the same samples and we will try to identify sunflower microRNA regulated genes in response to ABA. The ultimate goal will be improve sunflower breeding through selection of key drought response genes.-The experiment consisted of 3 repeats of four 12-day-old-plantlets of sunflower genotype SF193 (INRA code: XRQ) grown in growth chamber conditions and submitted to a 6-hour-treatment of 10 µM absissic acid or not. Growth conditions were 14h light at 23°C and 10h night at 20°C under fluorescent bulbs. Plants were grown in 6 hydroponic boxes containing 20 litres of aerated liquid culture medium (as described in Massonneau et al., 2001 Planta). Leaves (not cotyledons) 1 to 4 were harvested 4 hours after light onset and frozen immediately in liquid nitrogen.
Project description:Sunflower is an important source of vegetable oil worlwide. A differential organ-specific sunflower ESTs was previously generated by a subtractive hybridization method, including a considerable number of abiotic stress associated sequences. The objective of this work is to analyze the sunflower gene expression of previously identified candidate genes under a comprehensive microarray analysis of the leaf transcriptoma under cold and salinity stresses, considering the impacts of these abiotic stresses on sunflower yield in many productive areas. The aimed of this work is to perform genome analysis of sunflower based on its functional regions and the characterization of the sunflower transcriptoma profiles for different organ-specific genes. Abiotic-related expressed genes were the target of this characterization through a gene expression analysis of the local EST bank (annotated according to Gene Ontology Annotation) using a cDNA organ-specific microarray chip approach. We analyzed 287 differentially expressed genes derived from leaf, stem, R1 and R4 flower developmental stages. Transcriptional analysis allowed the detection of three different groups of genes according to their expression patterns. Group 1 contained 112 up-regulated genes under abiotic stress conditions (cold or salinity), whereas Group 2 (126 genes) did not show changes in their expression levels. On the other hand, 49 genes were classified as Group 3 included were down-regulated genes under both stresses. Eighty genes exhibited a significative fold change under abiotic stress conditions, being six of them validated by qRT-PCR. Microrarray profiling of cold and NaCl-treated sunflower leaves revealed dynamic changes in transcript abundance, including transcription factors, defense/stress related proteins, and effectors of homeostasis, all of which highlight the complexity of both stress responses. This finding provides identification of many transcriptional processes occurring under abiotic stress in sunflower for genes isolated from organ-specific cDNA libraries Keywords: gene expression profile of organ-specific sunflower transcriptoma in response to NaCl and cold
Project description:affy_sunflower_2010_13 - affy_sunflower_2010_13 - It concerns the interaction between ROS and hormones in dormancy release in sunflower seeds. ABA is responsible for dormancy maintenance, while GA and ethylene promote seed germination. Based on our results, ROS could represent good candidate to shift from a hormone signalling to another determining the dormancy state in sunflower seeds.-We aim to understand the mechanisms controlling sunflower seed dormancy at the transcriptomic level, by the application of treatments which maintain dormancy as ABA, or alleviate dormancy as ROS and ethylene. Transcripts comparison will be performed between dormant and non-dormant sunflower embryo imbibed 24h on water, on ABA, on methylviologen, a pro-oxidant compound or on ethylene.
Project description:affy_sunflower_2010_13 - affy_sunflower_2010_13 - It concerns the interaction between ROS and hormones in dormancy release in sunflower seeds. ABA is responsible for dormancy maintenance, while GA and ethylene promote seed germination. Based on our results, ROS could represent good candidate to shift from a hormone signalling to another determining the dormancy state in sunflower seeds.-We aim to understand the mechanisms controlling sunflower seed dormancy at the transcriptomic level, by the application of treatments which maintain dormancy as ABA, or alleviate dormancy as ROS and ethylene. Transcripts comparison will be performed between dormant and non-dormant sunflower embryo imbibed 24h on water, on ABA, on methylviologen, a pro-oxidant compound or on ethylene. 12 arrays - SUNFLOWER; treated vs untreated comparison
Project description:Abiotic stress and more specifically drought is the major limiting factor for sunflower production. ABA is a key hormone for drought stress response in plants and sunflower. This experiment aims at identifying ABA responsive pathways in order to better understand sunflower responses to drought. We studied in parallel microRNA profiles on the same samples and we will try to identify sunflower microRNA regulated genes in response to ABA. The ultimate goal will be improve sunflower breeding through selection of key drought response genes.-The experiment consisted of 3 repeats of four 12-day-old-plantlets of sunflower genotype SF193 (INRA code: XRQ) grown in growth chamber conditions and submitted to a 6-hour-treatment of 10 µM absissic acid or not. Growth conditions were 14h light at 23°C and 10h night at 20°C under fluorescent bulbs. Plants were grown in 6 hydroponic boxes containing 20 litres of aerated liquid culture medium (as described in Massonneau et al., 2001 Planta). Leaves (not cotyledons) 1 to 4 were harvested 4 hours after light onset and frozen immediately in liquid nitrogen. 6 arrays - SUNFLOWER; treated vs untreated comparison
Project description:Twenty-four sunflower genotypes were selected to represent genetic diversity within cultivated sunflower and included both inbred lines and their hybrids. Drought stress was applied to plants in pots at the vegetative stage using the high-throughput phenotyping platform Heliaphen. Here, we provide transcriptomics data from sunflower leaves. These data differentiate both treatment and the different genotypes and constitute a valuable resource to the community to study adaptation of crops to drought and the transcriptomic basis of heterosis.