Fabrication of trace elements incorporated apatite coating could combine the ions’ pharmaceutical effect into the materials. In this study, strontium, silicon, and fluoride ions have been incorporated into apatite co...Fabrication of trace elements incorporated apatite coating could combine the ions’ pharmaceutical effect into the materials. In this study, strontium, silicon, and fluoride ions have been incorporated into apatite coatings through a biomineralization method, which mimics an in vitro mineralization process. The surface composition is tested with X-ray diffraction and X-ray photoelectron spectroscopy, and the surface morphology is characterized with scanning electron microscopy. Compared with pure hydroxyapatite coating, the strontium, silicon, and fluoride substituted apatite coatings show different morphology as spherical, needle-like, and nano-flake-like, individually. The crystal size of these biomimetic hydroxyapatite coatings decreased after ion substitution. The results of the analysis of surface composition present the ion substitutions are increased with the increasing of ion concentrations in the soaking solution. That means the ion incorporation into the apatite structure based on the biomineralization method could not only vary the ion content in but also change the morphology of the apatite coatings. Herein, the role of ion substitution is considered from the point of view of materials science at the micro structural and surface chemistry levels.展开更多
Sequential carbohydrate synthesis is important for plant survival because it guarantees energy supplies for growth and development during plant ontogeny and reproduction. Starch and fructan are two important carbohydr...Sequential carbohydrate synthesis is important for plant survival because it guarantees energy supplies for growth and development during plant ontogeny and reproduction. Starch and fructan are two important carbohydrates in many flowering plants and in human diets. Understanding this coordinated starch and fructan synthesis and unraveling how plants allocate photosynthates and prioritize different carbohydrate synthesis for survival could lead to improvements to cereals in agriculture for the purposes of greater food security and production quality. Here, we report a system from a single gene in barley employing two alternative promoters, one intronic/exonic, to generate two sequence-overlapping but functionally opposing transcription factors, in sensing sucrose, potentially via sucrose/gluco lose 6-phosphate signaling. The system employs an autoregulatory mechanism in perceiving a sucrose- controlled trans activity on one promoter and orchestrating the coordinated starch and fructan synthesis by competitive transcription factor binding on the other promoter. As a case in point for the physiological roles of the system, we have demonstrated that this multitasking system can be exploited in breeding barley with tailored amounts of fructan to produce healthy food ingredients. The identification of an intron/exon-spanning promoter in a hosting gene, resulting in proteins with distinct functions, adds to the complexity of plant genomes.展开更多
基金This work was supported by BIOMATCELL,VINN Ex-cellence Center of Biomaterials and Cell Therapy.
文摘Fabrication of trace elements incorporated apatite coating could combine the ions’ pharmaceutical effect into the materials. In this study, strontium, silicon, and fluoride ions have been incorporated into apatite coatings through a biomineralization method, which mimics an in vitro mineralization process. The surface composition is tested with X-ray diffraction and X-ray photoelectron spectroscopy, and the surface morphology is characterized with scanning electron microscopy. Compared with pure hydroxyapatite coating, the strontium, silicon, and fluoride substituted apatite coatings show different morphology as spherical, needle-like, and nano-flake-like, individually. The crystal size of these biomimetic hydroxyapatite coatings decreased after ion substitution. The results of the analysis of surface composition present the ion substitutions are increased with the increasing of ion concentrations in the soaking solution. That means the ion incorporation into the apatite structure based on the biomineralization method could not only vary the ion content in but also change the morphology of the apatite coatings. Herein, the role of ion substitution is considered from the point of view of materials science at the micro structural and surface chemistry levels.
文摘Sequential carbohydrate synthesis is important for plant survival because it guarantees energy supplies for growth and development during plant ontogeny and reproduction. Starch and fructan are two important carbohydrates in many flowering plants and in human diets. Understanding this coordinated starch and fructan synthesis and unraveling how plants allocate photosynthates and prioritize different carbohydrate synthesis for survival could lead to improvements to cereals in agriculture for the purposes of greater food security and production quality. Here, we report a system from a single gene in barley employing two alternative promoters, one intronic/exonic, to generate two sequence-overlapping but functionally opposing transcription factors, in sensing sucrose, potentially via sucrose/gluco lose 6-phosphate signaling. The system employs an autoregulatory mechanism in perceiving a sucrose- controlled trans activity on one promoter and orchestrating the coordinated starch and fructan synthesis by competitive transcription factor binding on the other promoter. As a case in point for the physiological roles of the system, we have demonstrated that this multitasking system can be exploited in breeding barley with tailored amounts of fructan to produce healthy food ingredients. The identification of an intron/exon-spanning promoter in a hosting gene, resulting in proteins with distinct functions, adds to the complexity of plant genomes.
