AIM:To demonstrate that mitochondrial morphological andfunctional changes are an important intermediate link in thecourse of apoptosis in esophageal carcinoma calls inducedby As_2O_3.METHODS:The esophageal carcinoma c...AIM:To demonstrate that mitochondrial morphological andfunctional changes are an important intermediate link in thecourse of apoptosis in esophageal carcinoma calls inducedby As_2O_3.METHODS:The esophageal carcinoma call line SHEEC1,established in our laboratory,was cultured in 199 growthmedium,supplemented with 100mL·L^(-1)calf serum and3 mol·L^(-1)As_2O_3(the same below).After 2,4,6,12,24 hof drug adding,the SHEECl calls were collected for light-and electron-microscopic examination.The mitochondriawere labeled by Rhodamine fluorescence probe and thefluorescence intensity of the mitochondria was measured byflow cytorneter and cytofluorimetric analysis.Further,themitochondrial transmembrane potential(MTP,ΔΨm)change was also calculated.RESULTS:The mitochondrial morphological change afteradding As_2O_3 could be divided into three stages.In theearly-stage(2-6h)after adding As203,an adaptiveproliferation of mitochondria appeared;in the mid-stage(6-12 h)a degenerative change was observed;and in the late-stage(12-24 h)the mitochondria swelled with outermembrane broken down and then calls death with apoptoticchanges of nucleus.The functional change of themitochondria indicated by fluorescent intensity,whichreflected the MTP status of mitochondria,was in accordancewith morphological change of the mitochondria.Thefluorescent intensity increased at early-stage,decUned inmid-stage and decreased to the lowest in the late-stage.24h after As_2O_3 adding,the cell nucleus showed typicalapoptotic changes.CONCLUSION:Under the inducement of As_2O_3,the earlyapoptotic changes of SHEEC1 cells ware the apparentmorphological and functional changes of mitochondria,afterwards the nucleus changes followed.It is consideredthat changes of mitochondria are an important intermediatelink in the course of apoptosis of esophageal carcinoma cells induced by As_2O_3.展开更多
Laizhou Bay provides a critical spawning and nursery habitat for many fishery species, including commercially important spe- cies, such as Fenneropenaeus chinensis and Larimichthys polyactis. The bay is severely stres...Laizhou Bay provides a critical spawning and nursery habitat for many fishery species, including commercially important spe- cies, such as Fenneropenaeus chinensis and Larimichthys polyactis. The bay is severely stressed due to high fishing pressure and environmental changes. Based on the long-term ecosystem surveys in Laizhou Bay during the main spawning period （May） of most fishery species from 1959 to 2008, the responses of the Laizhou Bay fishery ecosystem were analyzed here, including regime shifts in species composition, biomass, species diversity, zooplankton, phytoplankton, and environmental variables. The dominant species of large-size and high economic value （e.g. Trichiurus haumela, L. polyactis） have been replaced by the short-lived, low-trophic-level planktivorous pelagic species （e.g. Setipinna taty, Engraulisjaponicus） since the 1980s, and it is probable that the small-sized pelagic fishes have been recently replaced by invertebrates （e.g. Oratosquilla oratoria, Crangon affinis）. The biomass of fishery resources declined continuously from 423.6 kg haul 1 h-1 in 1959 to 164.6 kg haul-l h i in 1982, 37.7 kg haul-1 h-1 in 1993, and less than 8 kg haul 1 h-a in 1998-2008. Moreover, the biomass of zooplankton showed an increasing trend during 1959-2006, but showed a slight decline in 2008. The abundance of phytoplankton increased from 1959 through 1982, decreased substantially in 1993, and increased again until 2004. More recently, however, the phytoplankton abundance was very low. The sea surface temperature （SST） and sea bottom temperature （SBT） in May increased by 0.23~C a-~ and 0.16~C a-~, respectively, during 1982-2008. The salinity in May showed large fluctuations and reached its lowest val- ues in 2004 and 2006. The ratio of dissolved inorganic nitrogen （DIN） to dissolved inorganic phosphate （DIP） increased. However, the dissolved silicon （DSi）：DIP and DSi：DIN ratios decreased to a low level during 1959-2008. These changes seri- ously impacted primary produ展开更多
Dear Editor, In the past few years, the use of sequence-specific nucle- ases for efficient targeted mutagenesis has provided plant biologists with a powerful new approach for understanding gene function and developin...Dear Editor, In the past few years, the use of sequence-specific nucle- ases for efficient targeted mutagenesis has provided plant biologists with a powerful new approach for understanding gene function and developing new traits. These nucleases create DNA double-strand breaks at chromosomal targeted sites that are primarily repaired by the non-homologous end joining （NHEJ） or homologous recombination （HR） pathways. NHEJ is o^en imprecise and can introduce mutations at tar- get sites resulting in the loss of gene function. In contrast, HR uses a homologous DNA template for repair and can be employed to create site-specific sequence modifications or targeted insertions （Moynahan and Jasin, 2010）.展开更多
The Cucurbita genus contains several economically important species in the Cucurbitaceae family. Here, we report high-quality genome sequences of C. maxima and C. moschata and provide evidence supporting an allotetrap...The Cucurbita genus contains several economically important species in the Cucurbitaceae family. Here, we report high-quality genome sequences of C. maxima and C. moschata and provide evidence supporting an allotetraploidization event in Cucurbita. We are able to partition the genome into two homoeologous subgenomes based on different genetic distances to melon, cucumber, and watermelon in the Benincaseae tribe. We estimate that the two diploid progenitors successively diverged from Benincaseae around 31 and 26 million years ago （Mya）, respectively, and the allotetraploidization happened at some point between 26 Mya and 3 Mya, the estimated date when C. maxima and C. moschata diverged. The subgenomes have largely maintained the chromosome structures of their diploid progenitors. Such long-term karyotype stability after polyploidization has not been commonly observed in plant polyploids. The two subgenomes have retained similar numbers of genes, and neither subgenome is globally dominant in gene expression. Allele-specific expression analysis in the C. maxima ×C. moschata interspecific F1 hybrid and their two parents indicates the predominance of trans-regulatory effects underlying expression divergence of the parents, and detects transgressive gene expression changes in the hybrid correlated with heterosis in important agronomic traits. Our study provides insights into polyploid genome evolution and valuable resources for genetic improvement of cucurbit crops.展开更多
AIM:To compare efficacy of combined lamivudine(LAM)and adefovir dipivoxil(ADV)therapy with that of entecavir(ETV)monotherapy for hepatitis B virus(HBV)-related decompensated liver cirrhosis.METHODS:A total of 120 na v...AIM:To compare efficacy of combined lamivudine(LAM)and adefovir dipivoxil(ADV)therapy with that of entecavir(ETV)monotherapy for hepatitis B virus(HBV)-related decompensated liver cirrhosis.METHODS:A total of 120 na ve patients with HBVrelated decompensated cirrhosis participated in this study.Sixty patients were treated with combined LAM and ADV therapy(LAM+ADV group),while the other60 were treated with ETV monotherapy(ETV group)for two years.Tests for liver and kidney function,alpha-fetoprotein,HBV serum markers,HBV DNA load,prothrombin time(PT),and ultrasonography or computed tomography scan of the liver were performed every1 to 3 mo.Repeated measure ANOVA and theχ2test were performed to compare the efficacy,side effects,and the cumulative survival rates at 48 and 96 wk.RESULTS:Forty-five patients in each group were observed for 96 wk.No significant differences in HBV DNA negative rates and alanine aminotransferase(ALT)normalization rates at weeks 48(χ2=2.12 and 2.88)and96(χ2=3.21 and 3.24)between the two groups were observed.Hepatitis B e antigen seroconversion rate in the LAM+ADV group at week 96 was significantly higher in the ETV group(43.5%vs 36.4%,χ2=4.09,P<0.05).Viral breakthrough occurred in 2 cases(4.4%)by week 48 and in 3 cases(6.7%)by week 96 in the LAM+ADV group,and no viral mutation was detected.In the ETV group,viral breakthrough occurred in 1 case(2.2%)at the end of week 96.An increase in albumin(F=18.9 and 17.3),decrease in total bilirubin and in ALT(F=16.5,17.1 and 23.7,24.8),reduced PT(F=22.7 and 24.5),and improved Child-Turcotte-Pugh and the model for end-stage liver disease scores(F=18.5,17.8,and 24.2,23.8)were observed in both groups.The cumulative rates of mortality and liver transplantation were 16.7%(10/60)and 18.3%(11/60)in the LAM+ADV and ETV groups,respectively.CONCLUSION:Both LAM+ADV combination therapy and ETV monotherapy can effectively inhibit HBV replication,improve liver function,and decrease mortality.展开更多
Background Fibrinogen-depleting agents are promising in the treatment of cerebral ischemic disease. They were studied by many trials, and the outcomes were different because of different regimens and different doses. ...Background Fibrinogen-depleting agents are promising in the treatment of cerebral ischemic disease. They were studied by many trials, and the outcomes were different because of different regimens and different doses. In this study, we assessed the efficacy and safety of defibrase on acute cerebral infarction in China. Methods A search using Chinese hospital knowledge database （CHKD） and MEDLINE database for randomized controlled trials was carded out. A CHKD （1994 June 2005） search was performed with the keyword ＂defibrase＂, then a second search for the keyword ＂acute cerebral infarction＂; a MEDLINE search （1950 June 2005） was performed with the following keywords： [（cerebral ischemia）, OR （acute cerebral infarction）, OR （stroke）], AND [defibrase]. Meta-analysis was performed with RevMan software 4.2. Results Included were 14 studies comparing the efficiency and safety of defibrase with other drugs in the treatment of acute cerebral infarction. Patients＇ records were pooled （total 646 patients; defibrase, n=328, no defibrase n=318）. Neurological deficit score （NDS） before treatment showed weighted mean differences （WMD）=0.95, 95% confidence interval （CI）= （-0.60, 2.50）, P=0.23; NDS after treatment showed WMD=- 2.20, 95% CI= （-4.21, -0.18）, P=0.03; Barthel index at 3 months showed WMD=4.45, 95% CI= （-0.13, 9.03）, P=0.06; the plasma fibrinogen level before treatment showed WMD=0.02, 95% CI= （-0.16, 0.19）, P=0.86; plasma fibrinogen level after treatment showed WMD=- 1.51, 95% CI= （- 1.88, - 1.15）, P〈0.00 001.Conclusions With the given dose and regimen of defibrase in China, defibrase may play a role of anticoagulation. It might inhibit the progression of stroke and prevent the recurrence of stroke.展开更多
Chlorophyll （Chl） degradation is an integral process of leaf senescence, and NYE1/SGR1 has been demonstrated as a key regulator of Chl catabolism in diverse plant species. In this study, using yeast one-hybrid scree...Chlorophyll （Chl） degradation is an integral process of leaf senescence, and NYE1/SGR1 has been demonstrated as a key regulator of Chl catabolism in diverse plant species. In this study, using yeast one-hybrid screening, we identified three abscisic acid （ABA）-responsive element （ABRE）-binding transcription factors, ABF2 （AREB1）, ABF3, and ABF4 （AREB2）, as the putative binding proteins of the NYE1 promoter. Through the transactivation analysis, electrophoretic mobility shift assay, and chromatin immunoprecipitation, we demonstrated that ABF2, ABF3, and ABF4 directly bound to and activated the NYE1 promoter in vitro and in vivo. ABA is a positive regulator of leaf senescence, and exogenously applied ABA can accelerate Chl degradation. The triple mutant of the ABFs, abf2abf3abf4, as well as two ABA-insensitive mutants, abil-1 and snrk2.2/2.3/2.6, exhibited stay-green phenotypes after ABA treatment, along with decreased induction of NYE1 and NYE2 expression. In contrast, overexpression of ABF4 accelerated Chl degradation upon ABA treatment. Interestingly, ABF2/3/4 could also activate the expression of two Chl catabolic enzyme genes, PAO and NYCl, by directly binding to their promoters. In addition, abf2abf3abf4 exhibited a functional stay-green phenotype, and senescence-associated genes （SAGs）, such as SAG29 （SWEET15）, might be directly regulated by the ABFs. Taken together, our results suggest that ABF2, ABF3, and ABF4 likely act as key regulators in mediating ABA-triggered Chl degradation and leaf senescence in general in Arabidopsis.展开更多
MicroRNAs （miRNAs） are pivotal modulators of plant development and host-virus interactions. However, the roles and action modes of specific miRNAs involved in viral infection and host susceptibility remain largely u...MicroRNAs （miRNAs） are pivotal modulators of plant development and host-virus interactions. However, the roles and action modes of specific miRNAs involved in viral infection and host susceptibility remain largely unclear. In this study, we show that Rice ragged stunt virus （RRSV） infection caused increased accumulation of miR319 but decreased expression of miR319-regulated TCP （TEOSINTE BRANCHED/ CYCLOIDEA/PCF） genes, especially TCP21, in rice plants. Transgenic rice plants overexpressing miP,319 or downregulating TCP21 exhibited disease-like phenotypes and showed significantly higher susceptibility to RRSV in comparison with the wild-type plants. In contrast, only mild disease symptoms were observed in RRSV-infected lines overexpressing TCP21 and especially in the transgenic plants overexpressing miR319- resistant TCP21. Both RRSV infection and overexpression of miR319 caused the decreased endogenous jasmonic acid （JA） levels along with downregulated expression of JA biosynthesis and signaling-related genes in rice. However, treatment of rice plants with methyl jasmonate alleviated disease symptoms caused by RRSV and reduced virus accumulation. Taken together, our results suggest that the induction of miR319 by RRSV infection in rice suppresses JA-mediated defense to facilitate virus infection and symp- tom development.展开更多
The Advanced Space-based Solar Observatory(ASO-S)is a mission proposed for the 25 th solar maximum by the Chinese solar community.The scientific objectives are to study the relationships between the solar magnetic fie...The Advanced Space-based Solar Observatory(ASO-S)is a mission proposed for the 25 th solar maximum by the Chinese solar community.The scientific objectives are to study the relationships between the solar magnetic field,solar flares and coronal mass ejections(CMEs).Three payloads are deployed:the Full-disk vector Magneto Graph(FMG),the Lyman-αSolar Telescope(LST)and the Hard X-ray Imager(HXI).ASO-S will perform the first simultaneous observations of the photospheric vector magnetic field,non-thermal imaging of solar flares,and the initiation and early propagation of CMEs on a single platform.ASO-S is scheduled to be launched into a 720 km Sun-synchronous orbit in 2022.This paper presents an overview of the mission till the end of Phase-B and the beginning of Phase-C.展开更多
基金the National Natural Science Foundation of China,No.39830380
文摘AIM:To demonstrate that mitochondrial morphological andfunctional changes are an important intermediate link in thecourse of apoptosis in esophageal carcinoma calls inducedby As_2O_3.METHODS:The esophageal carcinoma call line SHEEC1,established in our laboratory,was cultured in 199 growthmedium,supplemented with 100mL·L^(-1)calf serum and3 mol·L^(-1)As_2O_3(the same below).After 2,4,6,12,24 hof drug adding,the SHEECl calls were collected for light-and electron-microscopic examination.The mitochondriawere labeled by Rhodamine fluorescence probe and thefluorescence intensity of the mitochondria was measured byflow cytorneter and cytofluorimetric analysis.Further,themitochondrial transmembrane potential(MTP,ΔΨm)change was also calculated.RESULTS:The mitochondrial morphological change afteradding As_2O_3 could be divided into three stages.In theearly-stage(2-6h)after adding As203,an adaptiveproliferation of mitochondria appeared;in the mid-stage(6-12 h)a degenerative change was observed;and in the late-stage(12-24 h)the mitochondria swelled with outermembrane broken down and then calls death with apoptoticchanges of nucleus.The functional change of themitochondria indicated by fluorescent intensity,whichreflected the MTP status of mitochondria,was in accordancewith morphological change of the mitochondria.Thefluorescent intensity increased at early-stage,decUned inmid-stage and decreased to the lowest in the late-stage.24h after As_2O_3 adding,the cell nucleus showed typicalapoptotic changes.CONCLUSION:Under the inducement of As_2O_3,the earlyapoptotic changes of SHEEC1 cells ware the apparentmorphological and functional changes of mitochondria,afterwards the nucleus changes followed.It is consideredthat changes of mitochondria are an important intermediatelink in the course of apoptosis of esophageal carcinoma cells induced by As_2O_3.
基金supported by Special Fund for Agro-scientific Research in the Public Interest(Grant No.200903005)National Basic Research Program of China(Grant Nos.2011CB409805 and 2010CB951204)Taishan Scholar Program of Shandong Province
文摘Laizhou Bay provides a critical spawning and nursery habitat for many fishery species, including commercially important spe- cies, such as Fenneropenaeus chinensis and Larimichthys polyactis. The bay is severely stressed due to high fishing pressure and environmental changes. Based on the long-term ecosystem surveys in Laizhou Bay during the main spawning period （May） of most fishery species from 1959 to 2008, the responses of the Laizhou Bay fishery ecosystem were analyzed here, including regime shifts in species composition, biomass, species diversity, zooplankton, phytoplankton, and environmental variables. The dominant species of large-size and high economic value （e.g. Trichiurus haumela, L. polyactis） have been replaced by the short-lived, low-trophic-level planktivorous pelagic species （e.g. Setipinna taty, Engraulisjaponicus） since the 1980s, and it is probable that the small-sized pelagic fishes have been recently replaced by invertebrates （e.g. Oratosquilla oratoria, Crangon affinis）. The biomass of fishery resources declined continuously from 423.6 kg haul 1 h-1 in 1959 to 164.6 kg haul-l h i in 1982, 37.7 kg haul-1 h-1 in 1993, and less than 8 kg haul 1 h-a in 1998-2008. Moreover, the biomass of zooplankton showed an increasing trend during 1959-2006, but showed a slight decline in 2008. The abundance of phytoplankton increased from 1959 through 1982, decreased substantially in 1993, and increased again until 2004. More recently, however, the phytoplankton abundance was very low. The sea surface temperature （SST） and sea bottom temperature （SBT） in May increased by 0.23~C a-~ and 0.16~C a-~, respectively, during 1982-2008. The salinity in May showed large fluctuations and reached its lowest val- ues in 2004 and 2006. The ratio of dissolved inorganic nitrogen （DIN） to dissolved inorganic phosphate （DIP） increased. However, the dissolved silicon （DSi）：DIP and DSi：DIN ratios decreased to a low level during 1959-2008. These changes seri- ously impacted primary produ
文摘Dear Editor, In the past few years, the use of sequence-specific nucle- ases for efficient targeted mutagenesis has provided plant biologists with a powerful new approach for understanding gene function and developing new traits. These nucleases create DNA double-strand breaks at chromosomal targeted sites that are primarily repaired by the non-homologous end joining （NHEJ） or homologous recombination （HR） pathways. NHEJ is o^en imprecise and can introduce mutations at tar- get sites resulting in the loss of gene function. In contrast, HR uses a homologous DNA template for repair and can be employed to create site-specific sequence modifications or targeted insertions （Moynahan and Jasin, 2010）.
文摘The Cucurbita genus contains several economically important species in the Cucurbitaceae family. Here, we report high-quality genome sequences of C. maxima and C. moschata and provide evidence supporting an allotetraploidization event in Cucurbita. We are able to partition the genome into two homoeologous subgenomes based on different genetic distances to melon, cucumber, and watermelon in the Benincaseae tribe. We estimate that the two diploid progenitors successively diverged from Benincaseae around 31 and 26 million years ago （Mya）, respectively, and the allotetraploidization happened at some point between 26 Mya and 3 Mya, the estimated date when C. maxima and C. moschata diverged. The subgenomes have largely maintained the chromosome structures of their diploid progenitors. Such long-term karyotype stability after polyploidization has not been commonly observed in plant polyploids. The two subgenomes have retained similar numbers of genes, and neither subgenome is globally dominant in gene expression. Allele-specific expression analysis in the C. maxima ×C. moschata interspecific F1 hybrid and their two parents indicates the predominance of trans-regulatory effects underlying expression divergence of the parents, and detects transgressive gene expression changes in the hybrid correlated with heterosis in important agronomic traits. Our study provides insights into polyploid genome evolution and valuable resources for genetic improvement of cucurbit crops.
基金Supported by the National Key Program for Infectious Diseases of China to Yang YD,2013ZX1000200112th Five-Year Significant New Drugs Creation Plan of the Ministry of Science and Technology of China toYangYD,2011ZX09302-003-03
文摘AIM:To compare efficacy of combined lamivudine(LAM)and adefovir dipivoxil(ADV)therapy with that of entecavir(ETV)monotherapy for hepatitis B virus(HBV)-related decompensated liver cirrhosis.METHODS:A total of 120 na ve patients with HBVrelated decompensated cirrhosis participated in this study.Sixty patients were treated with combined LAM and ADV therapy(LAM+ADV group),while the other60 were treated with ETV monotherapy(ETV group)for two years.Tests for liver and kidney function,alpha-fetoprotein,HBV serum markers,HBV DNA load,prothrombin time(PT),and ultrasonography or computed tomography scan of the liver were performed every1 to 3 mo.Repeated measure ANOVA and theχ2test were performed to compare the efficacy,side effects,and the cumulative survival rates at 48 and 96 wk.RESULTS:Forty-five patients in each group were observed for 96 wk.No significant differences in HBV DNA negative rates and alanine aminotransferase(ALT)normalization rates at weeks 48(χ2=2.12 and 2.88)and96(χ2=3.21 and 3.24)between the two groups were observed.Hepatitis B e antigen seroconversion rate in the LAM+ADV group at week 96 was significantly higher in the ETV group(43.5%vs 36.4%,χ2=4.09,P<0.05).Viral breakthrough occurred in 2 cases(4.4%)by week 48 and in 3 cases(6.7%)by week 96 in the LAM+ADV group,and no viral mutation was detected.In the ETV group,viral breakthrough occurred in 1 case(2.2%)at the end of week 96.An increase in albumin(F=18.9 and 17.3),decrease in total bilirubin and in ALT(F=16.5,17.1 and 23.7,24.8),reduced PT(F=22.7 and 24.5),and improved Child-Turcotte-Pugh and the model for end-stage liver disease scores(F=18.5,17.8,and 24.2,23.8)were observed in both groups.The cumulative rates of mortality and liver transplantation were 16.7%(10/60)and 18.3%(11/60)in the LAM+ADV and ETV groups,respectively.CONCLUSION:Both LAM+ADV combination therapy and ETV monotherapy can effectively inhibit HBV replication,improve liver function,and decrease mortality.
文摘Background Fibrinogen-depleting agents are promising in the treatment of cerebral ischemic disease. They were studied by many trials, and the outcomes were different because of different regimens and different doses. In this study, we assessed the efficacy and safety of defibrase on acute cerebral infarction in China. Methods A search using Chinese hospital knowledge database （CHKD） and MEDLINE database for randomized controlled trials was carded out. A CHKD （1994 June 2005） search was performed with the keyword ＂defibrase＂, then a second search for the keyword ＂acute cerebral infarction＂; a MEDLINE search （1950 June 2005） was performed with the following keywords： [（cerebral ischemia）, OR （acute cerebral infarction）, OR （stroke）], AND [defibrase]. Meta-analysis was performed with RevMan software 4.2. Results Included were 14 studies comparing the efficiency and safety of defibrase with other drugs in the treatment of acute cerebral infarction. Patients＇ records were pooled （total 646 patients; defibrase, n=328, no defibrase n=318）. Neurological deficit score （NDS） before treatment showed weighted mean differences （WMD）=0.95, 95% confidence interval （CI）= （-0.60, 2.50）, P=0.23; NDS after treatment showed WMD=- 2.20, 95% CI= （-4.21, -0.18）, P=0.03; Barthel index at 3 months showed WMD=4.45, 95% CI= （-0.13, 9.03）, P=0.06; the plasma fibrinogen level before treatment showed WMD=0.02, 95% CI= （-0.16, 0.19）, P=0.86; plasma fibrinogen level after treatment showed WMD=- 1.51, 95% CI= （- 1.88, - 1.15）, P〈0.00 001.Conclusions With the given dose and regimen of defibrase in China, defibrase may play a role of anticoagulation. It might inhibit the progression of stroke and prevent the recurrence of stroke.
文摘Chlorophyll （Chl） degradation is an integral process of leaf senescence, and NYE1/SGR1 has been demonstrated as a key regulator of Chl catabolism in diverse plant species. In this study, using yeast one-hybrid screening, we identified three abscisic acid （ABA）-responsive element （ABRE）-binding transcription factors, ABF2 （AREB1）, ABF3, and ABF4 （AREB2）, as the putative binding proteins of the NYE1 promoter. Through the transactivation analysis, electrophoretic mobility shift assay, and chromatin immunoprecipitation, we demonstrated that ABF2, ABF3, and ABF4 directly bound to and activated the NYE1 promoter in vitro and in vivo. ABA is a positive regulator of leaf senescence, and exogenously applied ABA can accelerate Chl degradation. The triple mutant of the ABFs, abf2abf3abf4, as well as two ABA-insensitive mutants, abil-1 and snrk2.2/2.3/2.6, exhibited stay-green phenotypes after ABA treatment, along with decreased induction of NYE1 and NYE2 expression. In contrast, overexpression of ABF4 accelerated Chl degradation upon ABA treatment. Interestingly, ABF2/3/4 could also activate the expression of two Chl catabolic enzyme genes, PAO and NYCl, by directly binding to their promoters. In addition, abf2abf3abf4 exhibited a functional stay-green phenotype, and senescence-associated genes （SAGs）, such as SAG29 （SWEET15）, might be directly regulated by the ABFs. Taken together, our results suggest that ABF2, ABF3, and ABF4 likely act as key regulators in mediating ABA-triggered Chl degradation and leaf senescence in general in Arabidopsis.
文摘MicroRNAs （miRNAs） are pivotal modulators of plant development and host-virus interactions. However, the roles and action modes of specific miRNAs involved in viral infection and host susceptibility remain largely unclear. In this study, we show that Rice ragged stunt virus （RRSV） infection caused increased accumulation of miR319 but decreased expression of miR319-regulated TCP （TEOSINTE BRANCHED/ CYCLOIDEA/PCF） genes, especially TCP21, in rice plants. Transgenic rice plants overexpressing miP,319 or downregulating TCP21 exhibited disease-like phenotypes and showed significantly higher susceptibility to RRSV in comparison with the wild-type plants. In contrast, only mild disease symptoms were observed in RRSV-infected lines overexpressing TCP21 and especially in the transgenic plants overexpressing miR319- resistant TCP21. Both RRSV infection and overexpression of miR319 caused the decreased endogenous jasmonic acid （JA） levels along with downregulated expression of JA biosynthesis and signaling-related genes in rice. However, treatment of rice plants with methyl jasmonate alleviated disease symptoms caused by RRSV and reduced virus accumulation. Taken together, our results suggest that the induction of miR319 by RRSV infection in rice suppresses JA-mediated defense to facilitate virus infection and symp- tom development.
基金supported by the Strategic Priority Research Program on Space Science, Chinese Academy of Sciences (Grant Nos. XDA15320100, XDA15320102, XDA15320103, XDA15320104, XDA15320300 and XDA15052200)supported by the National Natural Science Foundation of China (Grant Nos. 11427803, U1731241, U1631242 and 11820101002)
文摘The Advanced Space-based Solar Observatory(ASO-S)is a mission proposed for the 25 th solar maximum by the Chinese solar community.The scientific objectives are to study the relationships between the solar magnetic field,solar flares and coronal mass ejections(CMEs).Three payloads are deployed:the Full-disk vector Magneto Graph(FMG),the Lyman-αSolar Telescope(LST)and the Hard X-ray Imager(HXI).ASO-S will perform the first simultaneous observations of the photospheric vector magnetic field,non-thermal imaging of solar flares,and the initiation and early propagation of CMEs on a single platform.ASO-S is scheduled to be launched into a 720 km Sun-synchronous orbit in 2022.This paper presents an overview of the mission till the end of Phase-B and the beginning of Phase-C.
