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.
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
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 30 hybs total
Project description:Bacterial community in floral nectar of Nicotiana glauca: The roles of environmental versus spatial factors along climatic gradient and across the globe