Project description:Background: Hypovirulent fungal strain Gibellulopsis nigrescens Vn-1 cross-protects sunflower against Verticillium wilt. To discover the mechanism of cross-protection by this hypovirulent strain, we analyzed defense enzyme activities and transcriptomes of root samples infected with virulent and hypovirulent strains. Results: Defense enzyme activities increased after inoculation, with the highest levels observed 24 h post-inoculation. At the same time, defense enzyme gene expressions were upregulated, and H2O2 accumulation decreased. A comparative transcriptome analysis revealed that there are 23 GO terms significantly enriched in the Vn-1 group compared with the control, including three specific oxidoreductase-related and four signaling related GO terms. In addition, there were 7 KEGG pathway only enriched in V33 group compared with the control, and 3 KEGG pathway (Alanine, aspartate and glutamate metabolism, Cutin, suberine and wax biosynthesis and Ribosome) only enriched in Vn-1 compared with the control. Conclusions: According to our results, both hypovirulent strain G. nigrescens Vn-1 and virulent strain V. dahliae V33 can reduce levels of reactive oxygen species in sunflower seedling by regulating HaCAT and HaPOD expression. Twenty three GO terms and three KEGG pathway contribute to the formation of specific resistance against virulent strain V. dahliae V33.
Project description:Purpose: Molecular analysis of chickpea-Foc interaction; Methods: Four LongSAGE libraries of wilt-resistant and wilt-susceptible chickpea cultivars prepared after Foc inoculation and sequenced using Ion Torrent PGM. Results: Transcriptome analyses revealed expression of several plant defense and pathogen virulence genes with their peculier expression patterns in wilt-resistant and wilt-susceptible chickpea cultivars. Conclusion: The study identified several candidate Foc resistant genes, which can be used for crop improvement after their functional validation.
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.