Leaf morphogenesis requires the establishment of adaxlal-abaxlal polarity after primordium initiation from the snoot apical meristem （SAM）. Several families of transcription factors are known to play critical roles ...Leaf morphogenesis requires the establishment of adaxlal-abaxlal polarity after primordium initiation from the snoot apical meristem （SAM）. Several families of transcription factors are known to play critical roles in promoting adaxial or abaxial leaf fate. Recently, post-transcriptional gene silencing pathways have been shown to regulate the establishment of leaf polarity, providing novel and exciting insights into leaf development. For example, microRNAs （miR 165/166） and a trans-acting siRNA （TAS3-derived tasiR-ARF） have been shown to repress the expression of several key transcription factor genes. In addition, yet another level of regulation, post-translational regulation, has been revealed recently by studies on the role of the 26S proteasome in leaf polarity. Although our understanding regarding the molecular mecha- nisms underlying establishment of adaxial-abaxial polarity has greatly improved, there is still much that remains elusive. This review aims to discuss recent progress, as well as the remaining questions, regarding the molecular mechanisms underlying leaf polarity formation.展开更多
The asymmetric leaves2 ( as2) is a classical Arabidopsis thaliana (L.) Heynh. mutant that shows leaf lobes and leaflet-like structures from the petioles of leaves. Genetic and molecular analyses have demonstrated that...The asymmetric leaves2 ( as2) is a classical Arabidopsis thaliana (L.) Heynh. mutant that shows leaf lobes and leaflet-like structures from the petioles of leaves. Genetic and molecular analyses have demonstrated that the AS2 function is required for repression of meristem-related homeobox genes in leaves. In this study, we describe phenotypic characterizations of new as2 alleles that are in the Landsberg erecta (Ler) genetic background. In addition to the as2 phenotypes reported previously, the new as2 mutants have some leaves with petiole growth underneath the leaf blade, showing a lotus-leaf structure. More severe rosettes leaves of the as2 mutants form a filament-like structure, reflecting a loss of the adaxial-abaxial polarity in leaves. Among as2 mutants analyzed in different genetic backgrounds, only those that are in the Ler genetic background resulted in a high frequency of the lotus-leaf structure. We have isolated the AS2 gene by map-based gene cloning. The predicted AS2 protein contains a leucine-zipper motif, and its N-terminus shares high levels of sequence similarity to those of a group of predicted proteins with no known biological functions. AS2 transcripts were detected in leaves, flowers and fruits, but absent in stems, consistent with the mutant phenotypes.展开更多
The physics that associated with the performance of lithium secondary batteries(LSB)are reviewed.The key physical problems in LSB include the electronic conduction mechanism,kinetics and thermodynamics of lithium ion ...The physics that associated with the performance of lithium secondary batteries(LSB)are reviewed.The key physical problems in LSB include the electronic conduction mechanism,kinetics and thermodynamics of lithium ion migration,electrode/electrolyte surface/interface,structural(phase)and thermodynamics stability of the electrode materials,physics of intercalation and deintercalation.The relationship between the physical/chemical nature of the LSB materials and the batteries performance is summarized and discussed.A general thread of computational materials design for LSB materials is emphasized concerning all the discussed physics problems.In order to fasten the progress of the new materials discovery and design for the next generation LSB,the Materials Genome Initiative(MGI)for LSB materials is a promising strategy and the related requirements are highlighted.展开更多
基金supported by grants from the National Natural Science Foundation of China(Nos.30630041,90208009)the Ministry of Science and Technology of China(No.04JC14077)the Shanghai Scientific Committee(No.KSCX2-YW-N-016)to H Huang.
文摘Leaf morphogenesis requires the establishment of adaxlal-abaxlal polarity after primordium initiation from the snoot apical meristem （SAM）. Several families of transcription factors are known to play critical roles in promoting adaxial or abaxial leaf fate. Recently, post-transcriptional gene silencing pathways have been shown to regulate the establishment of leaf polarity, providing novel and exciting insights into leaf development. For example, microRNAs （miR 165/166） and a trans-acting siRNA （TAS3-derived tasiR-ARF） have been shown to repress the expression of several key transcription factor genes. In addition, yet another level of regulation, post-translational regulation, has been revealed recently by studies on the role of the 26S proteasome in leaf polarity. Although our understanding regarding the molecular mecha- nisms underlying establishment of adaxial-abaxial polarity has greatly improved, there is still much that remains elusive. This review aims to discuss recent progress, as well as the remaining questions, regarding the molecular mechanisms underlying leaf polarity formation.
文摘The asymmetric leaves2 ( as2) is a classical Arabidopsis thaliana (L.) Heynh. mutant that shows leaf lobes and leaflet-like structures from the petioles of leaves. Genetic and molecular analyses have demonstrated that the AS2 function is required for repression of meristem-related homeobox genes in leaves. In this study, we describe phenotypic characterizations of new as2 alleles that are in the Landsberg erecta (Ler) genetic background. In addition to the as2 phenotypes reported previously, the new as2 mutants have some leaves with petiole growth underneath the leaf blade, showing a lotus-leaf structure. More severe rosettes leaves of the as2 mutants form a filament-like structure, reflecting a loss of the adaxial-abaxial polarity in leaves. Among as2 mutants analyzed in different genetic backgrounds, only those that are in the Ler genetic background resulted in a high frequency of the lotus-leaf structure. We have isolated the AS2 gene by map-based gene cloning. The predicted AS2 protein contains a leucine-zipper motif, and its N-terminus shares high levels of sequence similarity to those of a group of predicted proteins with no known biological functions. AS2 transcripts were detected in leaves, flowers and fruits, but absent in stems, consistent with the mutant phenotypes.
基金supported by the National Natural Science Foundation of China(Grant Nos.11234013,11064004 and 11264014)supported by the"Gan-po talent 555"project of Jiangxi Province
文摘The physics that associated with the performance of lithium secondary batteries(LSB)are reviewed.The key physical problems in LSB include the electronic conduction mechanism,kinetics and thermodynamics of lithium ion migration,electrode/electrolyte surface/interface,structural(phase)and thermodynamics stability of the electrode materials,physics of intercalation and deintercalation.The relationship between the physical/chemical nature of the LSB materials and the batteries performance is summarized and discussed.A general thread of computational materials design for LSB materials is emphasized concerning all the discussed physics problems.In order to fasten the progress of the new materials discovery and design for the next generation LSB,the Materials Genome Initiative(MGI)for LSB materials is a promising strategy and the related requirements are highlighted.
