Comparative transcriptomic analyses of high and low oleic acid content sunflower (Helianthus annuus L.) seed development
Ontology highlight
ABSTRACT: RNA sequencing in sunflower for detect mRNA expression of developmental seeds. The two cultivars (86-1, L-1-OL-1) with significant difference in oleic acid content in two different seed developmental stages (oleic acid accumulated rapidly at 17 DAF, and kept relatively stable at 27 DAF) for transcriptome sequencing
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:Comparative proteomic analysis between high-oleate ('L-1-OL-1') and low-oleate ('86-1') maintainer lines of sunflower based on iTRAQ (isobaric tags for relative and absolute quantification) was performed to identify key oleic acid synthesis-related proteins. These findings should enhance understanding of sunflower seed oleic acid synthesis mechanisms toward improving oil quality through breeding and germplasm-based measures.
Project description:We describe the design, cleaning and annotation of the gene index for sunflower and the construction of the microarray platform. In addition, we validate this tool by means of the analysis of global changes in gene expression profiles in response to water deficit as a physiological event which induces senescence, taken as a model experiment, for which reference genes have also been identified and validated (Fernandez et al., 2011). Our results show that Helianthus annuus L. microarray is suitable for a functional genomics approach across many different possible treatments and conditions to be carried out. Actually, it is already being used for other experiments showing a precise and accurate level of trustability along different gene expression profiles.
Project description:Sesquiterpene lactones (STL) are a subclass of isoprenoids with many known bioactivities frequently found in the Asteraceae family. In recent years, remarkable progress has been made regarding the biochemistry of STL, and today the biosynthetic pathway of the core backbones of many STLs has been elucidated. Consequently, the focus has shifted to the discovery of the decorating enzymes that can modify the core skeleton with functional hydroxy groups. Using in vivo pathway reconstruction assays in heterologous organisms such as Saccharomyces cerevisiae and Nicotiana benthamiana, we have analyzed several cytochrome P450 enzyme genes of the CYP71AX subfamily from Helianthus annuus clustered in close proximity to one another on the sunflower genome. We show that one member of this subfamily, CYP71AX36, can catalyze the conversion of costunolide to 14-hydroxycostunolide. The catalytic activity of CYP71AX36 may be of use for the chemoenzymatic production of antileukemic 14-hydroxycostunolide derivatives and other STLs of pharmaceutical interest. We also describe the full 2D-NMR assignment of 14-hydroxycostunolide and provide all 13C chemical shifts of the carbon skeleton for the first time.
Project description:This is the first complete mitochondrial genome sequence for sunflower and the first complete mitochondrial genome for any member of Asteraceae, the largest plant family, which includes over 23,000 named species. The master circle is 300,945-bp long and includes 27 protein-coding sequences, 18 tRNAs, and the 26S, 5S, and 18S rRNAs.