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Project description:A coordinated pathway for the synthesis of a novel blood-red pigment in a Mauritian nectar.
| PRJNA630452 | ENA
Project description:Nearly 90% of flowering plants depend on animals for reproduction. One of the main rewards plants offer to pollinators for visitation is nectar. Nesocodon mauritianus (Campanulaceae) produces a blood-red nectar that has been proposed to serve as a visual attractant for pollinator visitation. Here, we show that the nectar's red color is derived from a previously undescribed alkaloid termed nesocodin. The first nectar produced is acidic and pale yellow in color, but slowly becomes alkaline before taking on its characteristic red color. Three enzymes secreted into the nectar are either necessary or sufficient for pigment production, including a carbonic anhydrase that increases nectar pH, an aryl-alcohol oxidase that produces a pigment precursor, and a ferritin-like catalase that protects the pigment from degradation by hydrogen peroxide. Our findings demonstrate how these three enzymatic activities allow for the condensation of sinapaldehyde and proline to form a pigment with a stable imine bond. We subsequently verified that synthetic nesocodin is indeed attractive to Phelsuma geckos, the most likely pollinators of Nesocodon We also identify nesocodin in the red nectar of the distantly related and hummingbird-visited Jaltomata herrerae and provide molecular evidence for convergent evolution of this trait. This work cumulatively identifies a convergently evolved trait in two vertebrate-pollinated species, suggesting that the red pigment is selectively favored and that only a limited number of compounds are likely to underlie this type of adaptation.
| S-EPMC8812537 | biostudies-literature
Project description:Identification of nectary expressed genes
2014-12-31 | GSE43394 | GEO
Project description:Floral nectar proteins (nectarins) are mainly enzymes and play important roles in inhibiting microbial growth in nectar and tailoring nectar chemistry before or after secretory. Nectar proteomes are usually small, but only very few plant species have had their nectar proteomes thoroughly investigated. Nectarins from Nicotiana tabacum (NT) were separated using two-dimensional gel electrophoresis, and then analyzed using mass spectrometry. Glycoproteins were isolated from raw NT nectar, separated by SDS-PAGE, and identified by mass spectrometry. All eight identified nectarins and four invertase genes’ expression were analysed by qPCR. Sugars composition, total sugar concentration, protein content, polyphenol content and hydrogen peroxide content were compared at different time intervals in extracted nectar and nectar in situ after secretion. Totally, eight nectarins were detected in NT nectar in which only two are glycoproteins, beta-xylosidase and a protein with unknown function. All of the eight nectarin genes expression was not nectary-specific and not synchronous along with the nectary development. After secretion, NT nectar in flower tube changed from sucrose–rich to hexose-rich type even though no free invertase or its activity was detected in NT nectar. No sugar composition changes observed in extracted nectar after incubating at 30 ℃ up to 48 hours in plastic tubes. Our results indicate that nectar post-secretory changes could be a complex process and tissue closely contact with nectar might function in it.
2019-08-20 | PXD011658 | Pride
Project description:Primitive nucleated erythroid cells in the bloodstream have long been suggested to be more similar to nucleated red cells of fish, amphibians, and birds than the red cells of fetal and adult mammals. Rainbow trout Ficoll-purified red blood cells (RBCs) cultured in vitro undergo morphological changes, especially when exposed to stress, and enter a new cell stage that we have coined shape-shifted RBCs (shRBCs). We have characterized these shRBCs using transmission electron microscopy (TEM) micrographs, Wright⁻Giemsa staining, cell marker immunostaining, and transcriptomic and proteomic evaluation. shRBCs showed reduced density of the cytoplasm, hemoglobin loss, decondensed chromatin in the nucleus, and striking expression of the B lymphocyte molecular marker IgM. In addition, shRBCs shared some features of mammalian primitive pyrenocytes (extruded nucleus surrounded by a thin rim of cytoplasm and phosphatidylserine (PS) exposure on cell surface). These shRBCs were transiently observed in heat-stressed rainbow trout bloodstream for three days. Functional network analysis of combined transcriptomic and proteomic studies resulted in the identification of proteins involved in pathways related to the regulation of cell morphogenesis involved in differentiation, cellular response to stress, and immune system process. In addition, shRBCs increased interleukin 8 (IL8), interleukin 1 β (IL1β), interferon ɣ (IFNɣ), and natural killer enhancing factor (NKEF) protein production in response to viral hemorrhagic septicemia virus (VHSV). In conclusion, shRBCs may represent a novel cell stage that participates in roles related to immune response mediation, homeostasis, and the differentiation and development of blood cells.
| S-EPMC5946108 | biostudies-literature
Project description:Cucurbita maxima c.v. Big Max is a monoecious plant with separate male and female flowers which utilizes nectar as a floral reward for the attraction of bees to the flowers. Maintenance of this mutualism with bees is essential for the reproductive success in this economically valuable crop. In this study, the sex-dependent variation in composition of male and female nectar and the nectaries were defined using a combination of GC-MS based metabolomics and LC-MS/MS based proteomics. Nectar proteins were detected non-quantitatively using LC-MS/MS coupled to Orbitrap. The male and female nectary proteomes were quantified using iTRAQ labeled peptides which were fractioned and concatenated prior to detection using LC-MS/MS coupled to Orbitrap. The nectar proteome consists of 46 proteins, of which 70% overlap between nectar types. Only two proteins are unique to female nectar, and 10 are specific to male nectar. Nectarins (nectar proteins) commonly alter nectar carbohydrates. In our datasets, significant differences in carbohydrate abundance, specifically galactose and sucrose, may be explained by the unique presence of galactinol--sucrose galactosyltransferase 2 (functioning in galactose metabolism) and invertase (catalyzes the hydrolysis of sucrose to glucose and fructose) in the nectar of female and male flowers respectively. The nectary proteome contained 339 identifiable proteins, 71% of which were descriptively annotatable by homology to Plantae. The abundance of 45 proteins differs significantly between male and female nectaries. GO slim analysis revealed a high abundance of proteins related to transport, protein metabolism, carbohydrate metabolism, response to stress, and amino acid metabolism. Comparisons of relative protein abundance revealed that 45 proteins displayed differential expression between male and female nectaries (p-value <0.05); 20 of these proteins were more abundant in male nectaries and 25 were more abundant in female nectaries. GO enrichment of nectary proteins with increased female abundances indicate that female-enriched GO terms are associated with proteins functioning as plasma membrane proton pumps and central metabolism. Proteins associated with male nectary-enriched GO terms were related to cinnamic acid biosynthesis and neutralization of superoxide radicals and hydrogen peroxide.
2018-07-03 | PXD009810 | Pride
Project description:A series of environment-friendly clay minerals-α-Fe₂O₃ iron-red hybrid pigments-were prepared by a simple one-step hydrothermal reaction process using natural nanostructured silicate clay minerals as starting materials. The influence of structure, morphology and composition of different clay minerals on the structure, color properties, and stability of the pigments was studied comparatively by systematic structure characterizations with X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmittance electron microscope (TEM), X-ray fluorescence spectroscopy (XRF), X-ray photoelectron spectroscopy (XPS) and CIE-L*a*b* Colorimetric analyses. The results showed that the clay minerals act as green precipitants during the hydrothermal reaction to induce in-situ transformation of Fe(III) ions into Fe₂O₃ crystals. Meanwhile, they also act as the "micro-reactor" for forming Fe₂O₃ crystals and the supporter for inhibiting the aggregation of Fe₂O₃ nanoparticles. The color properties of iron-red hybrid pigments are closely related to the surface charges, surface silanol groups, and solid acid sites of clay minerals. The clay minerals with higher surface activity are more suitable to prepare iron-red pigments with better performance. The iron-red hybrid pigment derived from illite (ILL) clay showed the best red color performance with the color values of L* = 31.8, a* = 35.2, b* = 27.1, C* = 44.4 and h° = 37.6, and exhibited excellent stability in different chemical environments such as acid, alkaline, and also in high-temperature conditions.
| S-EPMC6266117 | biostudies-literature
Project description:Floral Nectaries Many plants secrete a rich floral nectar to entice visitation by insect and avian pollinators. In turn, these pollinators transfer pollen between flowers increasing plant fecundity. The nectary is the floral organ that secretes nectar into the base of the flower. The size and abundance of the ornamental tobacco nectaries (Nicotiana sp.) will permit us to isolate up to several grams of nectaries at each stage to obtain the necessary amounts of RNA for probe preparation. Our primary goals to understand the biochemistry the nectary, so that we can manipulate nectary function to increase pollinator visitation. We have previously conducted an EST study and have identified 13596 cDNAs from three different stages of nectary development (Stage 6, immature, presecretory nectaries; Stage 12, mature nectaries at floral anthesis; and nectaries, 44 hours after fertilization. In our efforts to evaluate the transcriptional program for the Nicotiana nectary we are proposing to evaluate nectary mRNAs by hybridization with the potato microarrays. We have preliminary evidence that wholesale transcriptional reprogramming (60% of the transcriptome) occurs during nectary maturation and again following fertilization. Our goal is to understand these processes at a biochemical level so that we can begin manipulating nectary function to improve nectar quality and quantity thereby increasing the attractiveness of flowers to insect pollinators. Such improvements have the potential to result in increases in insect visitation, seedset, and ultimately yield for insect pollinated crops. We are also making significant efforts to understand the restructuring of the nectary during its lifecycle. Many changes occur during nectary development and the observed transcriptional reprogramming makes sense the when these many changes are accounted for. Keywords: Loop design
2007-09-01 | GSE8245 | GEO
Project description:Obligate intracellular parasites must efficiently invade host cells in order to mature and be transmitted. For the malaria parasite Plasmodium falciparum, invasion of host red blood cells (RBCs) is essential. Here we describe a parasite-specific transcription factor PfAP2-I, belonging to the Apicomplexan AP2 (ApiAP2) family, that is responsible for regulating the expression of genes involved in RBC invasion. Our genome-wide analysis by ChIP-seq shows that PfAP2-I interacts with a specific DNA motif in the promoters of target genes. Although PfAP2-I contains three AP2 DNA-binding domains, only one is required for binding of the target genes during blood stage development. Furthermore, we find that PfAP2-I associates with several chromatin-associated proteins, including the Plasmodium bromodomain protein PfBDP1 and that complex formation is associated with transcriptional regulation. As a key regulator of red blood cell invasion, PfAP2-I represents a potential new antimalarial therapeutic target.
| S-EPMC5855115 | biostudies-literature
Project description:To identify the genes encoding the defense proteins and gain a deeper insight into the Ptt nectary transcriptom, poplar DNA microarrays (Affymetrix) were hybridized with RNA of extrafloral nectaries and nectary-free leaf sections Many plant species grow extrafloral nectaries and produce nectar to attract carnivore arthropods as defenders against herbivores. We studied in Populus how insect feeding feeds back on nectary development and activity. Two nectary types evolved with Populus trichocarpa (Ptr) and P. tremula x P. tremuloides (Ptt) were studied from their ecology down to the genes and molecules.
2012-08-03 | GSE23897 | GEO