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: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:affy_tour_2012-02 - Identification of transcripts that are addressed to traduction in imbibed seeds in relation with dormancy: comparison of the translatome in Dormant versus Non-Dormant seeds -- At harvest seeds are dormant. They stay dormant if they are stored at -20°C (D) and become non-dormant (ND) if they are stored 2 months at +20°C. Polysomal fractions were purified on sucrose gradients from sunflower axis isolated from dormant and non-dormant seeds imbibed at 10°C during 3h, 15h or 24h. - These fractions allow to identify the transcripts addressed to translation (translatome) during the seed imbibition process (3, 15 and 24h) - The translatome of 2 types of seeds are compared: Dormant vs Non-Dormant at the 3 time points. 18 arrays - SUNFLOWER; time course,treated vs untreated comparison
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: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:affy_sunflower_2011_02 - affy_sunflower_2011_02 - The early sowing constitutes an alternative strategy to avoid drought occurring during flowering and post-flowering periods and responsible for decrease in sunflower production. In French cropping system, early sowing is associated to low temperature period and frost during first development stages in sunflower. Knowledge about metabolism of frost acclimation must be performed to supply tools for breeding programs in sunflower. The aim of our experiment is to unravel the transcriptional regulation underpinning frost tolerance in sunflower-5 genotypes of sunflower were grown in a growth chamber 1 (23°C day/18°C night, 63% air humidity, 14 hours day photoperiod). At the stage of 6 leaves well-developed, 12 plants of each genotype were subjected to cold acclimation (+4°C during 2 days) in another growth chamber 2. Then, these plants were subjected to 2 nights at -3°C (frost treatment). Chlorophylle fluorescence, Osmotic potential, Relative electrolyte leakage were then determined in the following conditions : - 6th October on 6 plants X 5 genotypes from growth chamber 1 (C1) - 6th October on 6 plants X 5 genotypes from growth chamber 2 (S1) - 11th October on 6 plants X 5 genotypes from growth chamber 1 (C2) - 11th October on 6 plants X 5 genotypes from growth chamber 1 (S2)
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:affy_sunflower_2011_02 - affy_sunflower_2011_02 - The early sowing constitutes an alternative strategy to avoid drought occurring during flowering and post-flowering periods and responsible for decrease in sunflower production. In French cropping system, early sowing is associated to low temperature period and frost during first development stages in sunflower. Knowledge about metabolism of frost acclimation must be performed to supply tools for breeding programs in sunflower. The aim of our experiment is to unravel the transcriptional regulation underpinning frost tolerance in sunflower-5 genotypes of sunflower were grown in a growth chamber 1 (23°C day/18°C night, 63% air humidity, 14 hours day photoperiod). At the stage of 6 leaves well-developed, 12 plants of each genotype were subjected to cold acclimation (+4°C during 2 days) in another growth chamber 2. Then, these plants were subjected to 2 nights at -3°C (frost treatment). Chlorophylle fluorescence, Osmotic potential, Relative electrolyte leakage were then determined in the following conditions : - 6th October on 6 plants X 5 genotypes from growth chamber 1 (C1) - 6th October on 6 plants X 5 genotypes from growth chamber 2 (S1) - 11th October on 6 plants X 5 genotypes from growth chamber 1 (C2) - 11th October on 6 plants X 5 genotypes from growth chamber 1 (S2) 12 arrays - SUNFLOWER; treated vs untreated comparison