生长素参与植物生长和发育诸多过程,调控众多生理反应,在植物整个生命周期中自始至终发挥着调节作用.研究生长素的作用机制,对深入认识植物生长发育的生理过程有着重要的意义.综述了与生长素信号转导途径相关的3类主要蛋白组分:生长素/...生长素参与植物生长和发育诸多过程,调控众多生理反应,在植物整个生命周期中自始至终发挥着调节作用.研究生长素的作用机制,对深入认识植物生长发育的生理过程有着重要的意义.综述了与生长素信号转导途径相关的3类主要蛋白组分:生长素/吲哚乙酸蛋白(auxin/indoleacetic acids proteins,Aux/IAAs)、生长素响应因子(auxin response factors,ARFs)和SCF(SKP1-CDC53/CUL1-F-box)复合体,及相关的SGT1(suppressor of the G2 allele of skp1)基因,并对生长素相关基因表达的模式及其生物学功能进行了总结.展开更多
Auxin influences a variety of developmental and physiological processes. Early reports, suggested that auxin might affect plant stress response. We have identified a number of auxin responsive genes in Arabidopsis tha...Auxin influences a variety of developmental and physiological processes. Early reports, suggested that auxin might affect plant stress response. We have identified a number of auxin responsive genes in Arabidopsis thaliana (L.) Heynh. by using cDNA an-ay and found that stress responsive genes, such as,Arabidopsis homolog of MEK kinase 1 (ATMEKK1), ReL/SpoT homolog 3 ( At-RSH3), Catalase 1 ( Cat1) and Ferritin 1 (Fer1), were down-regulated by auxin, indicating that auxin regulates ale expression of stress responsive genes. We also demonstrated that nitrilase genes, nitrilase I ( NIT]) and nitrilase 2 (NIT2) involving in indole-3-acetic acid (IAA) biosynthesis, were induced by salinity stress, suggesting that the level of IAA might increase in response to salinity stress. To dissect the signal pathway involved in the interaction, two auxin insensitive mutants, auxin resistant 2 (axr2) and auxin resistant 1-3 (axrl-3) were used. Stress responsive genes were induced by salt stress in wild type and axr2, but not in axr1-3. The result suggests that die interaction between auxin and stress responses may be linked in the ubiquitin pathway.展开更多
AIM:To investigate the anti-tumor function of ginsenoside Rg3 on hepatocellular carcinoma(HCC) in vitro and in vivo,and its mechanism.METHODS:Hep1-6 and HepG2 cells were treated by Rg3 in different concentrations(0,50...AIM:To investigate the anti-tumor function of ginsenoside Rg3 on hepatocellular carcinoma(HCC) in vitro and in vivo,and its mechanism.METHODS:Hep1-6 and HepG2 cells were treated by Rg3 in different concentrations(0,50,100 and 200 μg/mL) in vitro.After incubation for 0,6,12,24 and 48 h,cell viability was measured by 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide assay.Apoptosis was identified by terminal deoxynucleotidyl transferasemediated dUTP-biotin nick end labeling.Caspase-3 activity was measured by chromophore p-nitroanilide and flow cytometry.Bcl-2 family proteins were ascertained by Western-blotting.Mitochondria membrane potentialwas detected by 5,5',6' 6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolylcarbocyanine iodide.Forty liver tumor-bearing C57Bl6 mice were divided randomly into 4 groups for intra-tumor injection of saline,ginsenoside Rg3,cyclophosphamide(CTX) and ginsenoside Rg3 + CTX combination.RESULTS:The survival time was followed up to 102 d.The mice in the Rg3 + CTX group showed significant increased survival time compared with those in the control group(P < 0.05).Rg3 could inhibit HCC cell proliferation and induce cell apoptosis in vitro in the concentration and time dependent manner.It also induced mitochondria membrane potential to decrease.Caspase-3 activation can be blocked by the inhibitor z-DEVD-FMK.Bax was up-regulated while Bcl-2 and Bcl-XL were down-regulated after Rg3 treatment.CONCLUSION:Our data suggested that Rg3 alone or combined with CTX inhibited tumor growth in vivo and prolonged mouse survival time by inducing HCC cell apoptosis via intrinsic pathway by expression alterations of Bcl-2 family proteins.展开更多
文摘生长素参与植物生长和发育诸多过程,调控众多生理反应,在植物整个生命周期中自始至终发挥着调节作用.研究生长素的作用机制,对深入认识植物生长发育的生理过程有着重要的意义.综述了与生长素信号转导途径相关的3类主要蛋白组分:生长素/吲哚乙酸蛋白(auxin/indoleacetic acids proteins,Aux/IAAs)、生长素响应因子(auxin response factors,ARFs)和SCF(SKP1-CDC53/CUL1-F-box)复合体,及相关的SGT1(suppressor of the G2 allele of skp1)基因,并对生长素相关基因表达的模式及其生物学功能进行了总结.
文摘Auxin influences a variety of developmental and physiological processes. Early reports, suggested that auxin might affect plant stress response. We have identified a number of auxin responsive genes in Arabidopsis thaliana (L.) Heynh. by using cDNA an-ay and found that stress responsive genes, such as,Arabidopsis homolog of MEK kinase 1 (ATMEKK1), ReL/SpoT homolog 3 ( At-RSH3), Catalase 1 ( Cat1) and Ferritin 1 (Fer1), were down-regulated by auxin, indicating that auxin regulates ale expression of stress responsive genes. We also demonstrated that nitrilase genes, nitrilase I ( NIT]) and nitrilase 2 (NIT2) involving in indole-3-acetic acid (IAA) biosynthesis, were induced by salinity stress, suggesting that the level of IAA might increase in response to salinity stress. To dissect the signal pathway involved in the interaction, two auxin insensitive mutants, auxin resistant 2 (axr2) and auxin resistant 1-3 (axrl-3) were used. Stress responsive genes were induced by salt stress in wild type and axr2, but not in axr1-3. The result suggests that die interaction between auxin and stress responses may be linked in the ubiquitin pathway.
基金Supported by The National Natural Science Foundation of China,No.30700778the Health Bureau Fund of Zhejiang Province,No.2007QN006,No.2008B080 and No.2008A050National Basic Research Program(973)of China,No.2007CB513005
文摘AIM:To investigate the anti-tumor function of ginsenoside Rg3 on hepatocellular carcinoma(HCC) in vitro and in vivo,and its mechanism.METHODS:Hep1-6 and HepG2 cells were treated by Rg3 in different concentrations(0,50,100 and 200 μg/mL) in vitro.After incubation for 0,6,12,24 and 48 h,cell viability was measured by 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide assay.Apoptosis was identified by terminal deoxynucleotidyl transferasemediated dUTP-biotin nick end labeling.Caspase-3 activity was measured by chromophore p-nitroanilide and flow cytometry.Bcl-2 family proteins were ascertained by Western-blotting.Mitochondria membrane potentialwas detected by 5,5',6' 6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolylcarbocyanine iodide.Forty liver tumor-bearing C57Bl6 mice were divided randomly into 4 groups for intra-tumor injection of saline,ginsenoside Rg3,cyclophosphamide(CTX) and ginsenoside Rg3 + CTX combination.RESULTS:The survival time was followed up to 102 d.The mice in the Rg3 + CTX group showed significant increased survival time compared with those in the control group(P < 0.05).Rg3 could inhibit HCC cell proliferation and induce cell apoptosis in vitro in the concentration and time dependent manner.It also induced mitochondria membrane potential to decrease.Caspase-3 activation can be blocked by the inhibitor z-DEVD-FMK.Bax was up-regulated while Bcl-2 and Bcl-XL were down-regulated after Rg3 treatment.CONCLUSION:Our data suggested that Rg3 alone or combined with CTX inhibited tumor growth in vivo and prolonged mouse survival time by inducing HCC cell apoptosis via intrinsic pathway by expression alterations of Bcl-2 family proteins.
