rd29A gene of Arabidopsis encodes a LEA-like hydrophilic protein, its expression is induced by drought, high-salt and cold stress. In the promoter region of rd29A gene, there are 2 ORE cis-acting elements involved in ...rd29A gene of Arabidopsis encodes a LEA-like hydrophilic protein, its expression is induced by drought, high-salt and cold stress. In the promoter region of rd29A gene, there are 2 ORE cis-acting elements involved in responses to these environmental stresses. 5 cDNAs (DREB1A-C and DREB2A-B) encoding DREB transcription factors, which specifically bind to ORE element and control the expression of reporter gene under drought, high-salt and stress, have been isolated by One-Hybrid screening method and with ORE element of rd29A promoter. DREB transcription factors and ORE element function in signal transduction of drought, high-salt and cold stress. One DREB transcription factor can control the expression of several target functional genes involved in plant tolerance to drought, high-salt and cold stress. Thus, it may be an effective strategy to achieve ideal, multiple and fundamental effect for improving plant stress-resistance by DREB gene transfer.展开更多
Iron is an essential element for life on Earth and its shortage, or excess, in the living organism may lead to severe health disorders. Plants serve as the primary source of dietary iron and improving crop iron conten...Iron is an essential element for life on Earth and its shortage, or excess, in the living organism may lead to severe health disorders. Plants serve as the primary source of dietary iron and improving crop iron content is an important step towards a better public health. Our review focuses on the control of iron acquisition in dicotyledonous plants and monocots that apply a reduction-based strategy in order to mobilize and import iron from the rhizosphere. Achieving a balance between shortage and excess of iron requires a tight regulation of the activity of the iron uptake system. A number of studies, ranging from single gene characterization to systems biology analyses, have led to the rapid expansion of our knowledge on iron uptake in recent years. Here, we summarize the novel insights into the regulation of iron ac- quisition and internal mobilization from intracellular stores. We present a detailed view of the main known regulatory networks defined by the Arabidopsis regulators FIT and POPEYE （PYE）. Additionally, we analyze the root and leaf iron- responsive regulatory networks, revealing novel potential gene interactions and reliable iron-deficiency marker genes. We discuss perspectives and open questions with regard to iron sensing and post-translational regulation.展开更多
The past two decades revealed a plethora of Ca^2＋-responsive proteins and downstream targets in plants, of which several are unique to plants. More recent high-throughput ＇omics＂ approaches and bioinformatics are e...The past two decades revealed a plethora of Ca^2＋-responsive proteins and downstream targets in plants, of which several are unique to plants. More recent high-throughput ＇omics＂ approaches and bioinformatics are exposing Ca^2＋-responsive cis-elements and the corresponding Ca^2＋-responsive genes. Here, we review the current knowledge on Ca^2＋-signaling pathways that regulate gene expression in plants, and we link these to mechanisms by which plants respond to biotic and abiotic stresses.展开更多
AIM: To observe the growth suppression effect of exogenous introduction of early growth response gene-1 (Egr-1 gene) on esophageal carcinoma tissue as well as on esophageal carcinoma cell line Eca109 and to explore th...AIM: To observe the growth suppression effect of exogenous introduction of early growth response gene-1 (Egr-1 gene) on esophageal carcinoma tissue as well as on esophageal carcinoma cell line Eca109 and to explore the potential application of Egr-1 gene in gene therapy of tumor. METHODS: Eukaryotic expression vector of PCMV-Egr-1 plasmid was introduced into Eca109 cell line which expressed no Egr-1 protein originally with lipofectamine transfection method. The introduction and expression of PCMV-Egr-1 plasmid into Eca109 cell line was confirmed by G418 selection culture, PCR amplification of neogene contained in the vector, Western blot analysis and immunocytochemical analysis. The cell growth curve, soft agar colony formation rate and tumorigenicity in SCID mice were examined to demonstrate the growth suppression effect of exogenous Egr-1 gene on Eca109 cell line. The Egr-1 mRNA and Egr-1 protein were also detected in 50 surgical specimens of esophageal carcinoma by in situ hybridization and immunohistochemistry. RESULTS: Exogenous Egr-1 gene was introduced successfully into Eca109 cell line and expressed Egr-1 protein stably. The transfected Eca109 cell line grew more slowly than control Eca109 as shown by cell growth curves, the soft agar colony formation rate (4.0% vs 6.9%, P 【 0.01) and the average growth rate of tumor in SCID mice (35.5 +/- 7.6 vs 65.8 +/- 7.6, P 【 0.05). The expression level of Egr-1 mRNA and protein significantly increased in dysplastic epithelia adjacent to cancer rather than in cancer tissues (65.8% vs 20.0% by ISH and 57.9% vs 0.01). CONCLUSION: Exogenous Egr-1 gene shows the strong effect of growth inhibition in Eca109 cell line. Egr-1 in the cancer tissue shows down-regulated expression that supports the inhibited function of Egr-1 in cancer growth and suggests Egr-1 may have an important role in gene therapy of esophageal carcinoma.展开更多
Heat shock transcription factors （Hsfs） play an essential role on the increased tolerance against heat stress by regulating the expression of heat-responsive genes. In this study, a genome-wide analysis was performe...Heat shock transcription factors （Hsfs） play an essential role on the increased tolerance against heat stress by regulating the expression of heat-responsive genes. In this study, a genome-wide analysis was performed to identify all of the soybean （Glycine max） GmHsfgenes based on the latest soybean genome sequence. Chromosomal location, protein domain, motif organization, and phylogenetic relationships of 26 non-redundant GmHsf genes were analyzed compared with AtHsfs （Arabidopsis thaliana Hsfs）. According to their structural features, the predicted members were divided into the previously defined classes A-C, as described for AtHsfs. Transcript levels and subcellular localization of five GmHsfs responsive to abiotic stresses were analyzed by real-time RT-PCR. These results provide a fundamental clue for understanding the complexity of the soybean GmHsfgene family and cloning the functional genes in future studies.展开更多
Tomato(Solanum lycopersicum)is a major horticultural crop worldwide and has emerged as a preeminent model for metabolic research.Although many research efforts have focused on the analysis of metabolite differences be...Tomato(Solanum lycopersicum)is a major horticultural crop worldwide and has emerged as a preeminent model for metabolic research.Although many research efforts have focused on the analysis of metabolite differences between varieties and species,the dynamics of metabolic changes during the tomato growth cycle and the regulatory networks that underlie these changes are poorly understood.In this study,we integrated high-resolution spatio-temporal metabolome and transcriptome data to systematically explore the metabolic landscape across 20 major tomato tissues and growth stages.In the resulting MicroTom Metabolic Network,the 540 detected metabolites and their co-expressed genes could be divided into 10 distinct clusters based on their biological functions.Using this dataset,we constructed a global map of the major metabolic changes that occur throughout the tomato growth cycle and dissected the underlying regulatory network.In addition to verifying previously well-established regulatory networks for important metabolites,we identified novel transcription factors that regulate the biosynthesis of important secondary metabolites such as steroidal glycoalkaloids and flavonoids.Our findings provide insights into spatiotemporal changes in tomato metabolism and generate a valuable resource for the study of metabolic regulatory processes in model plants.展开更多
Maintenance of homeostasis is pivotal to all forms of life. In the case of plants, homeostasis is constantly threatened by the inability to escape environmental fluctuations, and therefore sensitive mechanisms must ha...Maintenance of homeostasis is pivotal to all forms of life. In the case of plants, homeostasis is constantly threatened by the inability to escape environmental fluctuations, and therefore sensitive mechanisms must have evolved to allow rapid perception of environmental cues and concomitant modification of growth and developmental patterns for adaptation and survival. Re-establishment of homeostasis in response to environmental perturbations requires reprog- ramming of metabolism and gene expression to shunt energy sources from growth-related biosynthetic processes to defense, acclimation, and, ultimately, adaptation. Failure to mount an initial ＇emergency＇ response may result in nutrient deprivation and irreversible senescence and cell death. Early signaling events largely determine the capacity of plants to orchestrate a successful adaptive response. Early events, on the other hand, are likely to be shared by different conditions through the generation of similar signals and before more specific responses are elaborated. Recent studies lend credence to this hypothesis, underpinning the importance of a shared energy signal in the transcriptional response to various types of stress. Energy deficiency is associated with most environmental perturbations due to their direct or indirect deleterious impact on photosynthesis and/or respiration. Several systems are known to have evolved for monitoring the available resources and triggering metabolic, growth, and developmental decisions accordingly. In doing so, energy-sensing systems regulate gene expression at multiple levels to allow flexibility in the diversity and the kinetics of the stress response.展开更多
The secondary cell wall in mature cotton fibers contains over 90%cellulose with low quantities of xylan and lignin.However,little is known regarding the regulation of secondary cell wall biosynthesis in cotton fibers....The secondary cell wall in mature cotton fibers contains over 90%cellulose with low quantities of xylan and lignin.However,little is known regarding the regulation of secondary cell wall biosynthesis in cotton fibers.In this study,we characterized an R2R3-MYB transcription factor,Gh MYB7,in cotton.Gh MYB7 is expressed at a high level in developing fibers and encodes a MYB protein that is targeted to the cell nucleus and has transcriptional activation activity.Ectopic expression of Gh MYB7 in Arabidopsis resulted in small,curled,dark green leaves and also led to shorter inflorescence stems.A cross-sectional assay of basal stems revealed that cell wall thickness of vessels and interfascicular fibers was higher in transgenic lines overexpressing Gh MYB7 than in the wild type.Constitutive expression of Gh MYB7 in Arabidopsis activated the expression of a suite of secondary cell wall biosynthesis-related genes(including some secondary cell wall-associated transcription factors),leading to the ectopic deposition of cellulose and lignin.The ectopic deposition of secondary cell walls may have been initiated before the cessation of cell expansion.Moreover,Gh MYB7 was capable of binding to the promoter regions of At SND1 and At Ces A4,suggesting that Gh MYB7 may function upstream of NAC transcription factors.Collectively,these findings suggest that Gh MYB7 is a potential transcriptional activator,which may participate in regulating secondary cell wall biosynthesis of cotton fibers.展开更多
The tumor selective over-expression of the human Hsp70 gene has been well documented in human tumors,linked to the poor prognosis,being refractory to chemo-and radio-therapies as well as the advanced stage of tumorous...The tumor selective over-expression of the human Hsp70 gene has been well documented in human tumors,linked to the poor prognosis,being refractory to chemo-and radio-therapies as well as the advanced stage of tumorous lesions in particular.However,both the nature and details of aberrations in the control of the Hsp70 expression in tumor remain enigmatic.By comparing various upstream segments of the Hsp70 gene for each''s ability to drive the luciferase reporter genes in the context of the tumor cell lines varying in their p53 status and an immortal normal liver cell line,we demonstrated in a great detail the defects in the control mechanisms at the both initiation and elongation levels of transcription being instrumental to the tumor selective profile of its expression.Our data should not only offer new insights into our understanding of the tumor specific over-expression of the human Hsp70 gene,but also paved the way for the rational utilization of the tumor selective mechanism with the Hsp70 at the central stage fortargeting the therapeutic gene expression to human tumors.展开更多
文摘rd29A gene of Arabidopsis encodes a LEA-like hydrophilic protein, its expression is induced by drought, high-salt and cold stress. In the promoter region of rd29A gene, there are 2 ORE cis-acting elements involved in responses to these environmental stresses. 5 cDNAs (DREB1A-C and DREB2A-B) encoding DREB transcription factors, which specifically bind to ORE element and control the expression of reporter gene under drought, high-salt and stress, have been isolated by One-Hybrid screening method and with ORE element of rd29A promoter. DREB transcription factors and ORE element function in signal transduction of drought, high-salt and cold stress. One DREB transcription factor can control the expression of several target functional genes involved in plant tolerance to drought, high-salt and cold stress. Thus, it may be an effective strategy to achieve ideal, multiple and fundamental effect for improving plant stress-resistance by DREB gene transfer.
文摘Iron is an essential element for life on Earth and its shortage, or excess, in the living organism may lead to severe health disorders. Plants serve as the primary source of dietary iron and improving crop iron content is an important step towards a better public health. Our review focuses on the control of iron acquisition in dicotyledonous plants and monocots that apply a reduction-based strategy in order to mobilize and import iron from the rhizosphere. Achieving a balance between shortage and excess of iron requires a tight regulation of the activity of the iron uptake system. A number of studies, ranging from single gene characterization to systems biology analyses, have led to the rapid expansion of our knowledge on iron uptake in recent years. Here, we summarize the novel insights into the regulation of iron ac- quisition and internal mobilization from intracellular stores. We present a detailed view of the main known regulatory networks defined by the Arabidopsis regulators FIT and POPEYE （PYE）. Additionally, we analyze the root and leaf iron- responsive regulatory networks, revealing novel potential gene interactions and reliable iron-deficiency marker genes. We discuss perspectives and open questions with regard to iron sensing and post-translational regulation.
文摘The past two decades revealed a plethora of Ca^2＋-responsive proteins and downstream targets in plants, of which several are unique to plants. More recent high-throughput ＇omics＂ approaches and bioinformatics are exposing Ca^2＋-responsive cis-elements and the corresponding Ca^2＋-responsive genes. Here, we review the current knowledge on Ca^2＋-signaling pathways that regulate gene expression in plants, and we link these to mechanisms by which plants respond to biotic and abiotic stresses.
基金Supported by the National Natural Science Foundation of China,No.39670298.
文摘AIM: To observe the growth suppression effect of exogenous introduction of early growth response gene-1 (Egr-1 gene) on esophageal carcinoma tissue as well as on esophageal carcinoma cell line Eca109 and to explore the potential application of Egr-1 gene in gene therapy of tumor. METHODS: Eukaryotic expression vector of PCMV-Egr-1 plasmid was introduced into Eca109 cell line which expressed no Egr-1 protein originally with lipofectamine transfection method. The introduction and expression of PCMV-Egr-1 plasmid into Eca109 cell line was confirmed by G418 selection culture, PCR amplification of neogene contained in the vector, Western blot analysis and immunocytochemical analysis. The cell growth curve, soft agar colony formation rate and tumorigenicity in SCID mice were examined to demonstrate the growth suppression effect of exogenous Egr-1 gene on Eca109 cell line. The Egr-1 mRNA and Egr-1 protein were also detected in 50 surgical specimens of esophageal carcinoma by in situ hybridization and immunohistochemistry. RESULTS: Exogenous Egr-1 gene was introduced successfully into Eca109 cell line and expressed Egr-1 protein stably. The transfected Eca109 cell line grew more slowly than control Eca109 as shown by cell growth curves, the soft agar colony formation rate (4.0% vs 6.9%, P 【 0.01) and the average growth rate of tumor in SCID mice (35.5 +/- 7.6 vs 65.8 +/- 7.6, P 【 0.05). The expression level of Egr-1 mRNA and protein significantly increased in dysplastic epithelia adjacent to cancer rather than in cancer tissues (65.8% vs 20.0% by ISH and 57.9% vs 0.01). CONCLUSION: Exogenous Egr-1 gene shows the strong effect of growth inhibition in Eca109 cell line. Egr-1 in the cancer tissue shows down-regulated expression that supports the inhibited function of Egr-1 in cancer growth and suggests Egr-1 may have an important role in gene therapy of esophageal carcinoma.
基金supported by Basic Science Research Program through the National Research Foundation of Korea(KRF) funded by the Ministry of Education, Science and Technology (Grant Nos. KRF-2012-001205 and KRF-2012-001273)the Next-Generation BioGreen 21 Program funded by the Rural Development Administration, Republic of Korea (Grant No. PJ007970)
文摘Heat shock transcription factors （Hsfs） play an essential role on the increased tolerance against heat stress by regulating the expression of heat-responsive genes. In this study, a genome-wide analysis was performed to identify all of the soybean （Glycine max） GmHsfgenes based on the latest soybean genome sequence. Chromosomal location, protein domain, motif organization, and phylogenetic relationships of 26 non-redundant GmHsf genes were analyzed compared with AtHsfs （Arabidopsis thaliana Hsfs）. According to their structural features, the predicted members were divided into the previously defined classes A-C, as described for AtHsfs. Transcript levels and subcellular localization of five GmHsfs responsive to abiotic stresses were analyzed by real-time RT-PCR. These results provide a fundamental clue for understanding the complexity of the soybean GmHsfgene family and cloning the functional genes in future studies.
基金This study was funded by grants from the National Natural Science Foundation of China(31701255,31772372,and 31670352)Y.Z.was supported by the Fundamental Research Funds for the Central Universities(2017SCU04A11 and SCU2019D013)+1 种基金M.L.acknowledges support from the National Key R&D Program of China(2016YFD0400100)S.A.and A.R.F.acknowledge support from the PlantaSYST project of the European Union’s Horizon 2020 research and innovation program(SGA-CSA no.664621 and no.739582 under FPA no.664620).
文摘Tomato(Solanum lycopersicum)is a major horticultural crop worldwide and has emerged as a preeminent model for metabolic research.Although many research efforts have focused on the analysis of metabolite differences between varieties and species,the dynamics of metabolic changes during the tomato growth cycle and the regulatory networks that underlie these changes are poorly understood.In this study,we integrated high-resolution spatio-temporal metabolome and transcriptome data to systematically explore the metabolic landscape across 20 major tomato tissues and growth stages.In the resulting MicroTom Metabolic Network,the 540 detected metabolites and their co-expressed genes could be divided into 10 distinct clusters based on their biological functions.Using this dataset,we constructed a global map of the major metabolic changes that occur throughout the tomato growth cycle and dissected the underlying regulatory network.In addition to verifying previously well-established regulatory networks for important metabolites,we identified novel transcription factors that regulate the biosynthesis of important secondary metabolites such as steroidal glycoalkaloids and flavonoids.Our findings provide insights into spatiotemporal changes in tomato metabolism and generate a valuable resource for the study of metabolic regulatory processes in model plants.
文摘Maintenance of homeostasis is pivotal to all forms of life. In the case of plants, homeostasis is constantly threatened by the inability to escape environmental fluctuations, and therefore sensitive mechanisms must have evolved to allow rapid perception of environmental cues and concomitant modification of growth and developmental patterns for adaptation and survival. Re-establishment of homeostasis in response to environmental perturbations requires reprog- ramming of metabolism and gene expression to shunt energy sources from growth-related biosynthetic processes to defense, acclimation, and, ultimately, adaptation. Failure to mount an initial ＇emergency＇ response may result in nutrient deprivation and irreversible senescence and cell death. Early signaling events largely determine the capacity of plants to orchestrate a successful adaptive response. Early events, on the other hand, are likely to be shared by different conditions through the generation of similar signals and before more specific responses are elaborated. Recent studies lend credence to this hypothesis, underpinning the importance of a shared energy signal in the transcriptional response to various types of stress. Energy deficiency is associated with most environmental perturbations due to their direct or indirect deleterious impact on photosynthesis and/or respiration. Several systems are known to have evolved for monitoring the available resources and triggering metabolic, growth, and developmental decisions accordingly. In doing so, energy-sensing systems regulate gene expression at multiple levels to allow flexibility in the diversity and the kinetics of the stress response.
基金the National Natural Science Foundation of China (31371234)the project from the Ministry of Agriculture of China for transgenic research (2014ZX08009-27B)
文摘The secondary cell wall in mature cotton fibers contains over 90%cellulose with low quantities of xylan and lignin.However,little is known regarding the regulation of secondary cell wall biosynthesis in cotton fibers.In this study,we characterized an R2R3-MYB transcription factor,Gh MYB7,in cotton.Gh MYB7 is expressed at a high level in developing fibers and encodes a MYB protein that is targeted to the cell nucleus and has transcriptional activation activity.Ectopic expression of Gh MYB7 in Arabidopsis resulted in small,curled,dark green leaves and also led to shorter inflorescence stems.A cross-sectional assay of basal stems revealed that cell wall thickness of vessels and interfascicular fibers was higher in transgenic lines overexpressing Gh MYB7 than in the wild type.Constitutive expression of Gh MYB7 in Arabidopsis activated the expression of a suite of secondary cell wall biosynthesis-related genes(including some secondary cell wall-associated transcription factors),leading to the ectopic deposition of cellulose and lignin.The ectopic deposition of secondary cell walls may have been initiated before the cessation of cell expansion.Moreover,Gh MYB7 was capable of binding to the promoter regions of At SND1 and At Ces A4,suggesting that Gh MYB7 may function upstream of NAC transcription factors.Collectively,these findings suggest that Gh MYB7 is a potential transcriptional activator,which may participate in regulating secondary cell wall biosynthesis of cotton fibers.
文摘The tumor selective over-expression of the human Hsp70 gene has been well documented in human tumors,linked to the poor prognosis,being refractory to chemo-and radio-therapies as well as the advanced stage of tumorous lesions in particular.However,both the nature and details of aberrations in the control of the Hsp70 expression in tumor remain enigmatic.By comparing various upstream segments of the Hsp70 gene for each''s ability to drive the luciferase reporter genes in the context of the tumor cell lines varying in their p53 status and an immortal normal liver cell line,we demonstrated in a great detail the defects in the control mechanisms at the both initiation and elongation levels of transcription being instrumental to the tumor selective profile of its expression.Our data should not only offer new insights into our understanding of the tumor specific over-expression of the human Hsp70 gene,but also paved the way for the rational utilization of the tumor selective mechanism with the Hsp70 at the central stage fortargeting the therapeutic gene expression to human tumors.
