Project description:Survey of post pollination events in a sexually deceptive orchid (Ophrys fusca): a transcriptional approach Pollination through deception is a widespread phenomenon in angiosperm, and is extremely common in Orchidaceae family. One of the most striking pollination mechanism in orchids is known as sexual deception, in which flowers lure pollinators by foraging chemical (sex pheromones), visual (e.g. labellum colour and/or shape) and tactile (e.g. labellum pilosity) cues of the female insect pollinator. Ophrys has been used as a model genus to study sexual deception mechanism, mainly regarding chemical analysis in plant-insect association. Study was focused on Ophrys fusca, a species widely distributed in Mediterranean Basin. The main objective rely on Ophrys fusca gene expression study after pollination, through a transcriptional approach using cDNA microarrays. In order to evaluate pollination enhanced events, two different time points were selected: 2 days and 4 days after pollination. Ophrys fusca plants were sampled from a Portuguese natural occurring population. Plants were covered with a white and inert net, built specially for preventing pollinator’s visits in both pollinated and unpollinated flowers. Cross- pollination was performed manually with a sterile plastic stick. Five biological replicates (5 plants in each replicate) from each condition (pollinated and unpollinated) were collected in each time-point Flowers that demonstrate strict pollination regulation, as orchids, provide an excellent model system to unravel pollination- elicited mechanisms (i.e. petal senescence, pigmentation changes, ovary growth). Therefore, this study aims to contribute to the overall knowledge on orchid pollination biology, which is still lacking.
Project description:Survey of post pollination events in a sexually deceptive orchid (Ophrys fusca): a transcriptional approach Pollination through deception is a widespread phenomenon in angiosperm, and is extremely common in Orchidaceae family. One of the most striking pollination mechanism in orchids is known as sexual deception, in which flowers lure pollinators by foraging chemical (sex pheromones), visual (e.g. labellum colour and/or shape) and tactile (e.g. labellum pilosity) cues of the female insect pollinator. Ophrys has been used as a model genus to study sexual deception mechanism, mainly regarding chemical analysis in plant-insect association. Study was focused on Ophrys fusca, a species widely distributed in Mediterranean Basin. The main objective rely on Ophrys fusca gene expression study after pollination, through a transcriptional approach using cDNA microarrays. In order to evaluate pollination enhanced events, two different time points were selected: 2 days and 4 days after pollination. Ophrys fusca plants were sampled from a Portuguese natural occurring population. Plants were covered with a white and inert net, built specially for preventing pollinator’s visits in both pollinated and unpollinated flowers. Cross- pollination was performed manually with a sterile plastic stick. Five biological replicates (5 plants in each replicate) from each condition (pollinated and unpollinated) were collected in each time-point Flowers that demonstrate strict pollination regulation, as orchids, provide an excellent model system to unravel pollination- elicited mechanisms (i.e. petal senescence, pigmentation changes, ovary growth). Therefore, this study aims to contribute to the overall knowledge on orchid pollination biology, which is still lacking. 2 time points: 2 days and 4 days after pollination.Two-samples accessed: control (nonpollinated labella) and test (pollinated labella). 5 Biological replicates and 2 technical replicates (repeats of labelling and hybridization using randomly chosen biological replicates) in each time point were made.
Project description:Proteomics data from a combind transcriptome/proteome study of three sexually deceptive orchids of the genus Ophrys. Data are from labella of mature, unpollinated flowers of (1) Ophrys exaltata subsp. archipelagi, (2) O. sphegodes, and (3) O. garganica. Proteomics data were searched against SwissProt and TAIR databases and further against organism-specific databases obtained from transcriptome sequencing (454, Sanger ESTs and Solexa data). Thirteen trypsinised gel slices per sample were subjected to electrospray ionisation-based LC-MS/MS analysis with a 2D linear ion trap Finnigan LTQ (Thermo Electron Corporation) equipped with an Ultimate Nano HPLC System (Dionex Corporation). Mass spectra were searched against SwissProt and Arabidopsis TAIR9 protein databases to identify peptides. Additionally, spectra were searched against protein databases created from the Ophrys reference transcriptome obtained in this study. Stringent criteria were used for the assignment of spectra to peptides (95% peptide identification probability) in Scaffold 3.3 (Proteome Software Inc., USA). In order to maximise the utility of proteomics data for uncovering proteins predicted by the orchid transcriptome, a minimum of one unique peptide was used for protein identification, while using two different stringency levels for the probabilistic assignment of peptides to proteins (99% for highest quality, HQ; 90% to maximise protein discovery, PD, in the absence of a fully sequenced genome). Concerning the sequencing and transcriptomics results: Three normalised cDNA libraries were constructed from three different Ophrys species, O. exaltata, O. garganica, and O. sphegodes. These libraries were 454 pyrosequenced and all the high quality reads generated in this study are available in the Sequence Read Archive (SRA) of the National Centre for Biotechnology Information (NCBI) with the accession number SRA060767. Additional sequencing of O. sphegodes flower labella yielded 1.7 Mbp of Sanger (dbEST library LIBEST_028084; dbEST IDs 77978749-77979571; GenBank accessions JZ163765-JZ164587) and 2.5 Gbp of Illumina Solexa (SRA060767) data.