The economic alga Neopyropia,which holds significant value in China for its edibility and economic potential,harbors diverse epiphytic bacteria on its surface.The epiphytic bacteria on Neopyropia yezoensis and Neopyro...The economic alga Neopyropia,which holds significant value in China for its edibility and economic potential,harbors diverse epiphytic bacteria on its surface.The epiphytic bacteria on Neopyropia yezoensis and Neopyropia katadae,two nori species of Neopyropia living at the same tidal level but with distinct physiological states and living habits,were investigated to understand the differences between them and the effects of epiphytic bacteria on their differential characteristics.Analysis of 16S rRNA gene sequences and real-time quantitative PCR(qPCR)of thalli and seawater samples(n=24)revealed notable differences in microbial diversity and community structure between the two species.Bacteroidetes dominated the bacterial communities in association with N.yezoensis,whereas Proteobacteria were predominant in N.katadae.Phylogenetic Investigation of Communities by Reconstruction of Unobserved States(PICRUSt2)analysis revealed enriched genes that related to the ABC transport system,iron complex outer membrane receptor proteins,and proliferation in N.yezoensis,whereas N.katadae exhibited enrichment of genes that related to energy supply as well as cell wall and cell membrane production.The results of qPCR indicate a higher abundance of epiphytic bacteria on surface of N.yezoensis than those on surface of N.katadae.The findings indicate that differences in the living environments of N.yezoensis and N.katadae may result in distinct structural composition and abundance of epiphytic bacteria on their surfaces,thereby conferring specific biological functionalities to each microbial community,and the epiphytic bacteria may shape the living habits of hosts to some extents.This study provided a basis for understanding the close association between surface microorganisms and algal bodies,and the physiological and ecological characteristics of nori species.展开更多
Colloidal CdSe nanoplatelets are thin semiconductor materials with atomic flatness surfaces and one-dimensional strong quantum confinement,and hence they own very narrow and anisotropic emission.Here,we present a poly...Colloidal CdSe nanoplatelets are thin semiconductor materials with atomic flatness surfaces and one-dimensional strong quantum confinement,and hence they own very narrow and anisotropic emission.Here,we present a polydimethylsiloxane(PDMS)assisted transferring method that can pick up single layer CdSe nanoplatelet films self-assembled on a liquid surface and then precisely transfer to a target.By layer-by-layer picking up and transferring,multiple layers of CdSe films can be built up to form CdSe stacks with each single layer having dominant in-plane transition dipole distribution,which both material and energic structures are analogous to traditional multiple quantum wells grown by molecular-beam epitaxy.Additionally,with the great flexibility of colloidal nanoplatelets and this transferring method,CdSe nanoplatelets films can be combined with other materials to form hybrid heterostructures.We transferred a single-layer CdSe film onto WS_(2) flakes,and precisely studied the fast energy transfer rate with controlled CdSe nanoplatelet orientation and by using a streak camera with a ps time resolution.展开更多
The genus Pyropia contains several important cultivated species.Genetic research in nori species has mainly focused on the cell nucleus,with few studies on organelles(chloroplast and mitochondria).Due to the high copy...The genus Pyropia contains several important cultivated species.Genetic research in nori species has mainly focused on the cell nucleus,with few studies on organelles(chloroplast and mitochondria).Due to the high copy numbers of organelles in cells,which influence the development and traits of algae,it is necessary to study their genetic mechanism.In this study,the marine red alga Pyropia yezoensis,an important economic macroalga,was selected as the study object.To investigate organelle(chloroplast and mitochondria)inheritance in P.yezoensis,the wild type RZ(maternal strain)was crossed with the red mutant HT(paternal strain)and 30 color-sectors from 11 F1 gametophytic blades were examined.The complete chloroplast and mitochondrial genomes of the red mutant(HT)were assembled for the first time.One reliable and stable single nucleotide polymorphism(SNP)loci filtrated by bioinformatics analysis was used as a molecular marker for chloroplast and mitochondrial DNA,respectively,in subsequent experiments.PCR amplification and sequence analysis showed that the haplotypes of color-sectors detected were consistent with those of the maternal parent,confirming that both chloroplast and mitochondrial genomes were inherited maternally in P.yezoensis.The inheritance pattern of organelles in P.yezoensis can be used to guide the hybridization and breeding of nori.Additionally,the organelle SNP markers developed in this study can be applied in subsequent genetic research.展开更多
The phosphatidylinositol(PI)signaling system,a central regulator of eukaryotic metabolism,is widely found in eukaryotes for regulating a variety of cell activities.Most of the genes in the PI signaling system were fou...The phosphatidylinositol(PI)signaling system,a central regulator of eukaryotic metabolism,is widely found in eukaryotes for regulating a variety of cell activities.Most of the genes in the PI signaling system were found conserved in Pyropia yezoensis.In this experiment,wortmannin was used as an inhibitor to inhibit the activity of phosphatidylinositol-3 kinase(PI3K),an important regulator of the PI signaling system.After wortmannin treatment,the mitotic division of P.yezoensis was signifi cantly inhibited in a dose-dependent manner,and the mitotic division percentage was reduced by 68.1%and 91.9%in the 5-and 10-μmol/L groups,respectively.When thalli were treated with wortmannin,the levels of reactive oxygen species(ROS)were signifi cantly decreased.Furthermore,the expression level of PI3K was inhibited and the expression levels of downstream genes regulated by PI3K was signifi cantly changed.In the PI3K-AGC signaling pathway,the expression levels of Serine/threonine protein kinase(AGC)and cyclindependent kinases A(CDKA)were downregulated,while WEE1 kinase gene(WEE1)was upregulated.Three nicotinamide adenine dinucleotide phosphate(NADPH)oxidase genes were downregulated after wortmannin treatment.These results indicate that the PI signaling system plays an important role in the regulation of cell activity in P.yezoensis.It was speculated that the growth and development of P.yezoensis might be regulated by P.yezoensis PI3K,which promoted the expression of the AGC gene and further regulates the expression of downstream WEE1 and CDKA genes to advance mitotic division,and also promoted the expression level of NADPH oxidase that regulates ROS homeostasis.展开更多
Charge carrier dynamics essentially determines the performance of various optoelectronic applications of colloidal semiconductor nanocrystals.Among them,two-dimensional nanoplatelets provide new adjustment freedom for...Charge carrier dynamics essentially determines the performance of various optoelectronic applications of colloidal semiconductor nanocrystals.Among them,two-dimensional nanoplatelets provide new adjustment freedom for their unique core/crown heterostructures.Herein,we demonstrate that by fine-tuning the core size and the lateral quantum confinement,the charge carrier transfer rate from the crown to the core can be varied by one order of magnitude in CdSe/CdSeS core/alloy-crown nanoplatelets.In addition,the transfer can be affected by a carrier blocking mechanism,i.e.,the filled carriers hinder further possible transfer.Furthermore,we found that the biexciton interaction is oppositely affected by quantum confinement and electron delocalization,resulting in a non-monotonic variation of the biexciton binding energy with the emission wavelength.This work provides new observations and insights into the charge carrier transfer dynamics and exciton interactions in colloidal nanoplatelets and will promote their further applications in lasing,display,sensing,etc.展开更多
基金Supported by the National Natural Science Foundation of China(Nos.42276148,41976133)。
文摘The economic alga Neopyropia,which holds significant value in China for its edibility and economic potential,harbors diverse epiphytic bacteria on its surface.The epiphytic bacteria on Neopyropia yezoensis and Neopyropia katadae,two nori species of Neopyropia living at the same tidal level but with distinct physiological states and living habits,were investigated to understand the differences between them and the effects of epiphytic bacteria on their differential characteristics.Analysis of 16S rRNA gene sequences and real-time quantitative PCR(qPCR)of thalli and seawater samples(n=24)revealed notable differences in microbial diversity and community structure between the two species.Bacteroidetes dominated the bacterial communities in association with N.yezoensis,whereas Proteobacteria were predominant in N.katadae.Phylogenetic Investigation of Communities by Reconstruction of Unobserved States(PICRUSt2)analysis revealed enriched genes that related to the ABC transport system,iron complex outer membrane receptor proteins,and proliferation in N.yezoensis,whereas N.katadae exhibited enrichment of genes that related to energy supply as well as cell wall and cell membrane production.The results of qPCR indicate a higher abundance of epiphytic bacteria on surface of N.yezoensis than those on surface of N.katadae.The findings indicate that differences in the living environments of N.yezoensis and N.katadae may result in distinct structural composition and abundance of epiphytic bacteria on their surfaces,thereby conferring specific biological functionalities to each microbial community,and the epiphytic bacteria may shape the living habits of hosts to some extents.This study provided a basis for understanding the close association between surface microorganisms and algal bodies,and the physiological and ecological characteristics of nori species.
基金supported by Beijing Natural Science Foundation(grant no.Z190005)the National Natural Science Foundation of China(grant nos.61875002)the National Key R&D Program of China(grant no.2018YFA0306302)。
文摘Colloidal CdSe nanoplatelets are thin semiconductor materials with atomic flatness surfaces and one-dimensional strong quantum confinement,and hence they own very narrow and anisotropic emission.Here,we present a polydimethylsiloxane(PDMS)assisted transferring method that can pick up single layer CdSe nanoplatelet films self-assembled on a liquid surface and then precisely transfer to a target.By layer-by-layer picking up and transferring,multiple layers of CdSe films can be built up to form CdSe stacks with each single layer having dominant in-plane transition dipole distribution,which both material and energic structures are analogous to traditional multiple quantum wells grown by molecular-beam epitaxy.Additionally,with the great flexibility of colloidal nanoplatelets and this transferring method,CdSe nanoplatelets films can be combined with other materials to form hybrid heterostructures.We transferred a single-layer CdSe film onto WS_(2) flakes,and precisely studied the fast energy transfer rate with controlled CdSe nanoplatelet orientation and by using a streak camera with a ps time resolution.
基金Supported by the National Key R&D Program of China(Nos.2018YFD0900106,2018YFC1406700)the Marine S&T Fund of Shandong Province for Pilot National Laboratory for Marine Science and Technology(Qingdao)(No.2018SDKJ0302-4)the MOA Modern Agricultural Talents Support Project。
文摘The genus Pyropia contains several important cultivated species.Genetic research in nori species has mainly focused on the cell nucleus,with few studies on organelles(chloroplast and mitochondria).Due to the high copy numbers of organelles in cells,which influence the development and traits of algae,it is necessary to study their genetic mechanism.In this study,the marine red alga Pyropia yezoensis,an important economic macroalga,was selected as the study object.To investigate organelle(chloroplast and mitochondria)inheritance in P.yezoensis,the wild type RZ(maternal strain)was crossed with the red mutant HT(paternal strain)and 30 color-sectors from 11 F1 gametophytic blades were examined.The complete chloroplast and mitochondrial genomes of the red mutant(HT)were assembled for the first time.One reliable and stable single nucleotide polymorphism(SNP)loci filtrated by bioinformatics analysis was used as a molecular marker for chloroplast and mitochondrial DNA,respectively,in subsequent experiments.PCR amplification and sequence analysis showed that the haplotypes of color-sectors detected were consistent with those of the maternal parent,confirming that both chloroplast and mitochondrial genomes were inherited maternally in P.yezoensis.The inheritance pattern of organelles in P.yezoensis can be used to guide the hybridization and breeding of nori.Additionally,the organelle SNP markers developed in this study can be applied in subsequent genetic research.
基金Supported by the National Key R&D Program of China(Nos.2018YFD0900106,2020YFD0901101)the Marine S&T Fund of Shandong Province for Pilot National Laboratory for Marine Science and Technology(Qingdao)(No.2018SDKJ0302-4)+2 种基金the Fundamental Research Funds for the Central Universities(No.202064006)the MOA Modern Agricultural Talents Support ProjectSpecial Project of Central Government Guiding Local Science and Technology Development(No.7033204020)。
文摘The phosphatidylinositol(PI)signaling system,a central regulator of eukaryotic metabolism,is widely found in eukaryotes for regulating a variety of cell activities.Most of the genes in the PI signaling system were found conserved in Pyropia yezoensis.In this experiment,wortmannin was used as an inhibitor to inhibit the activity of phosphatidylinositol-3 kinase(PI3K),an important regulator of the PI signaling system.After wortmannin treatment,the mitotic division of P.yezoensis was signifi cantly inhibited in a dose-dependent manner,and the mitotic division percentage was reduced by 68.1%and 91.9%in the 5-and 10-μmol/L groups,respectively.When thalli were treated with wortmannin,the levels of reactive oxygen species(ROS)were signifi cantly decreased.Furthermore,the expression level of PI3K was inhibited and the expression levels of downstream genes regulated by PI3K was signifi cantly changed.In the PI3K-AGC signaling pathway,the expression levels of Serine/threonine protein kinase(AGC)and cyclindependent kinases A(CDKA)were downregulated,while WEE1 kinase gene(WEE1)was upregulated.Three nicotinamide adenine dinucleotide phosphate(NADPH)oxidase genes were downregulated after wortmannin treatment.These results indicate that the PI signaling system plays an important role in the regulation of cell activity in P.yezoensis.It was speculated that the growth and development of P.yezoensis might be regulated by P.yezoensis PI3K,which promoted the expression of the AGC gene and further regulates the expression of downstream WEE1 and CDKA genes to advance mitotic division,and also promoted the expression level of NADPH oxidase that regulates ROS homeostasis.
基金This work was supported by the National Natural Science Foundation of China(No.61875002)the National Key R&D Program of China(No.2018YFA0306302)+4 种基金the Beijing Natural Science Foundation(No.Z190005)the Program of State Key Laboratory of Quantum Optics and Quantum Optics Devices(No.KF202208)The author acknowledges the support of the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDB36000000)the National Natural Science Foundation of China(Nos.11874130 and 22073022)the support from the DNL Cooperation Fund,CAS(No.DNL202016)of Dalian National Laboratory for Clean Energy。
文摘Charge carrier dynamics essentially determines the performance of various optoelectronic applications of colloidal semiconductor nanocrystals.Among them,two-dimensional nanoplatelets provide new adjustment freedom for their unique core/crown heterostructures.Herein,we demonstrate that by fine-tuning the core size and the lateral quantum confinement,the charge carrier transfer rate from the crown to the core can be varied by one order of magnitude in CdSe/CdSeS core/alloy-crown nanoplatelets.In addition,the transfer can be affected by a carrier blocking mechanism,i.e.,the filled carriers hinder further possible transfer.Furthermore,we found that the biexciton interaction is oppositely affected by quantum confinement and electron delocalization,resulting in a non-monotonic variation of the biexciton binding energy with the emission wavelength.This work provides new observations and insights into the charge carrier transfer dynamics and exciton interactions in colloidal nanoplatelets and will promote their further applications in lasing,display,sensing,etc.