Glutaredoxins （GRXs） are ubiquitous oxidoreductases that play a crucial role in response to oxidative stress by reducing disulfides in various organisms. In planta, three different GRX classes have been identified a...Glutaredoxins （GRXs） are ubiquitous oxidoreductases that play a crucial role in response to oxidative stress by reducing disulfides in various organisms. In planta, three different GRX classes have been identified according to their active site motifs. CPYC and CGFS classes are found in all organisms, whereas the CC-type class is specific for higher land plants. Recently, two Arabidopsis CC-type GRXs, ROXY1 and ROXY2, were shown to exert crucial functions in petal and anther initiation and differentiation. To analyze the function of CC-type GRXs in the distantly related monocots, we isolated and characterized OsROXY1 and OsROXY2-two rice homologs of ROXY1. Both genes are expressed in vegetative and reproductive stages. Although rice flower morphology is distinct from eudicots, OsROXY1/2 floral expression patterns are similar to their Arabidopsis counterparts ROXY1/2. Complementation experiments demonstrate that OsROXY1 and OsROXY2 can fully rescue the roxyl floral mutant phenotype. Overexpression of OsROXY1, OsROXY2, and ROXY1 in Arabidopsis causes similar vegetative and reproductive plant developmental defects. ROXY1 and its rice homologs thus exert a conserved function during eudicot and monocot flower development. Strikingly, overexpression of these CC-type GRXs also leads to an increased accumulation of hydrogen peroxide levels and hyper-susceptibility to infection from the necrotrophic pathogen Botrytis cinerea, revealing the importance of balanced redox processes in flower organ develop- ment and pathogen defence.展开更多
Objective To study the chemical constituents from Desmodium triquetrum and their antihyperlipidemic activities. Methods The constituents of D. triquetrumwere isolated and purified using various column chromatographies...Objective To study the chemical constituents from Desmodium triquetrum and their antihyperlipidemic activities. Methods The constituents of D. triquetrumwere isolated and purified using various column chromatographies. Their chemical structures were elucidated using extensive spectroscopic methods. The lipid-lowering effects of the isolates were evaluated in HepG2 cells. Results Nine compounds were obtained from the ethanol extract of D. triquetrum and determined to be 6＇-O-cis-p-coumaroyl- 3,5-dihydroxyphenyl-β-D-glucopyranoside （1）, tadehaginoside （2）, rutin （3）, quercetin-3-O-β-D-glucopyranoside （4）, quercetin-3-O-β-D-galactopyranoside （5）, 6-O-（E）-p-hydroxy-cinnamoyl-β-glucose （6）, 6-O-（E）-p-hydroxy-cinnamoyl-α-glucose （7）, kaempferol-3-O-β-D-rutinoside （8）, and 3-O-β-D-galacopyranosyl （6-1）-α-L- rhamnosyl quercetin （9）. Compounds 1 and 2 significantly reduced the intracellular content of total cholesterols and triglycerides. Conclusion Compound 1 is a new phenolic compound and exhibits potent anti-hyperlipidemic activity. Additionally, compounds 6 and 7 are isolated from D. triquetrum for the first time.展开更多
文摘Glutaredoxins （GRXs） are ubiquitous oxidoreductases that play a crucial role in response to oxidative stress by reducing disulfides in various organisms. In planta, three different GRX classes have been identified according to their active site motifs. CPYC and CGFS classes are found in all organisms, whereas the CC-type class is specific for higher land plants. Recently, two Arabidopsis CC-type GRXs, ROXY1 and ROXY2, were shown to exert crucial functions in petal and anther initiation and differentiation. To analyze the function of CC-type GRXs in the distantly related monocots, we isolated and characterized OsROXY1 and OsROXY2-two rice homologs of ROXY1. Both genes are expressed in vegetative and reproductive stages. Although rice flower morphology is distinct from eudicots, OsROXY1/2 floral expression patterns are similar to their Arabidopsis counterparts ROXY1/2. Complementation experiments demonstrate that OsROXY1 and OsROXY2 can fully rescue the roxyl floral mutant phenotype. Overexpression of OsROXY1, OsROXY2, and ROXY1 in Arabidopsis causes similar vegetative and reproductive plant developmental defects. ROXY1 and its rice homologs thus exert a conserved function during eudicot and monocot flower development. Strikingly, overexpression of these CC-type GRXs also leads to an increased accumulation of hydrogen peroxide levels and hyper-susceptibility to infection from the necrotrophic pathogen Botrytis cinerea, revealing the importance of balanced redox processes in flower organ develop- ment and pathogen defence.
基金National Natural Science Foundation of China (81202994,81001437)China Postdoctoral Science Foundation (2012M510361)Technological Large Platform for Comprehensive Research and Development of New Drugs in the Twelfth Five-Year Significant New Drugs Created Science and Technology Major Projects (2012ZX09301-002-001-026)
文摘Objective To study the chemical constituents from Desmodium triquetrum and their antihyperlipidemic activities. Methods The constituents of D. triquetrumwere isolated and purified using various column chromatographies. Their chemical structures were elucidated using extensive spectroscopic methods. The lipid-lowering effects of the isolates were evaluated in HepG2 cells. Results Nine compounds were obtained from the ethanol extract of D. triquetrum and determined to be 6＇-O-cis-p-coumaroyl- 3,5-dihydroxyphenyl-β-D-glucopyranoside （1）, tadehaginoside （2）, rutin （3）, quercetin-3-O-β-D-glucopyranoside （4）, quercetin-3-O-β-D-galactopyranoside （5）, 6-O-（E）-p-hydroxy-cinnamoyl-β-glucose （6）, 6-O-（E）-p-hydroxy-cinnamoyl-α-glucose （7）, kaempferol-3-O-β-D-rutinoside （8）, and 3-O-β-D-galacopyranosyl （6-1）-α-L- rhamnosyl quercetin （9）. Compounds 1 and 2 significantly reduced the intracellular content of total cholesterols and triglycerides. Conclusion Compound 1 is a new phenolic compound and exhibits potent anti-hyperlipidemic activity. Additionally, compounds 6 and 7 are isolated from D. triquetrum for the first time.
