scholarly journals The Arabidopsis transcription factor ABIG1 relays ABA signaled growth inhibition and drought induced senescence

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Tie Liu ◽  
Adam D Longhurst ◽  
Franklin Talavera-Rauh ◽  
Samuel A Hokin ◽  
M Kathryn Barton
Keyword(s):  
Transcription Factor ◽  
Growth Inhibition ◽  
Stress Responses ◽  
Stomatal Closure ◽  
Mrna Levels ◽  
Wild Type ◽  
Drought Resistant ◽  
Aba Insensitive ◽  
Senesced Leaves ◽  
New Strategies

Drought inhibits plant growth and can also induce premature senescence. Here we identify a transcription factor, ABA INSENSITIVE GROWTH 1 (ABIG1) required for abscisic acid (ABA) mediated growth inhibition, but not for stomatal closure. ABIG1 mRNA levels are increased both in response to drought and in response to ABA treatment. When treated with ABA, abig1 mutants remain greener and produce more leaves than comparable wild-type plants. When challenged with drought, abig1 mutants have fewer yellow, senesced leaves than wild-type. Induction of ABIG1 transcription mimics ABA treatment and regulates a set of genes implicated in stress responses. We propose a model in which drought acts through ABA to increase ABIG1 transcription which in turn restricts new shoot growth and promotes leaf senescence. The results have implications for plant breeding: the existence of a mutant that is both ABA resistant and drought resistant points to new strategies for isolating drought resistant genetic varieties.

Sox4 Downregulates Pu.1 Gene Expression by Binding to An Upper Regulatory Element of Pu.1, a Mechanism Contributing to Leukemogenesis.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3979-3979
Author(s):  
Georg Aue ◽  
Yang Du ◽  
Susan Cleveland ◽  
Stephen Smith ◽  
Utpal P. Dave ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Transcription Factor ◽  
Vector Control ◽  
Myeloid Leukemia ◽  
Integration Site ◽  
Regulatory Element ◽  
Myeloid Cells ◽  
Binding Motif ◽  
Mrna Levels ◽  
Wild Type

Abstract Abstract 3979 Poster Board III-915 Mice that express 20% the normal levels of the Ets transcription factor Pu.1 develop AML, unlike mice that express 50% to 90% the normal levels, indicating that Pu.1 is a dosage-sensitive tumor suppressor gene. Furthermore, 3 of 13 AMLs induced by transplanting mice with cells transduced with a Sox4 oncogene-containing retrovirus were found to carry a Sox4 retroviral integration in one Pu.1 allele, suggesting that downregulation of Pu.1 may cooperate with Sox4 in AML induction. Since the other Pu.1 allele remains intact in these AMLs and a 50% decrease in Pu.1 expression is not sufficient to induce AML, we hypothesized that Sox4 might further downregulate Pu.1 expression in these AMLs. To test this hypothesis, we transfected HL60 promyelocytes with an expression vector carrying both GFP and Sox4 cDNAs or a GFP vector control. Transfected GFP+ cells were purified by flow cytometry and Pu.1 mRNA levels were analyzed by real-time RT-PCR. Pu.1 mRNA levels were consistently downregulated 4 to 10 fold in cells transfected with Sox4 cDNA compared to cells transfected with the vector control, while Beta-actin mRNA levels were maintained constant, confirming that overexpression of Sox4 downregulates Pu.1 expression in myeloid cells. The decrease of Pu.1 mRNA was observed as early as 8 hours after Sox4 transfection, further suggesting that Sox4 may directly repress the Pu.1 promoter in myeloid cells. Consistent with this, analysis of a published microarray databases comprising 285 de novo AML patient samples showed that SOX4 expression is significantly negatively correlated with Pu.1 expression (r= -0.337, p-value<0.001). In order to confirm that downregulation of Pu.1 cooperates with Sox4 in AML induction, we infected Pu.1 heterozygous knockout or wild type bone marrow cells with the Sox4 retrovirus and then monitored the time of AML development in transplanted mice. An increased penetrance of myeloid leukemia was observed in mice transplanted with Sox4-infected Pu.1 +/- bone marrow (95%) compared to mice receiving Sox4-infected wild type marrow (60%, p<0.001). Myeloid leukemia was confirmed by histology in all animals (100%) of the Sox4-infected Pu.1 +/ cohort. A Southern blot with a Sox4 probe confirmed clonal integrations. Consistent with our hypothesis, integration site analysis of the Sox4-infected Pu.1 +/- cohort tumor spleen DNA could not detect a Pu.1 integration site. Binding motif analysis found a Sox4 binding site in an upper regulatory element (URE) 14 kb upstream of the Pu.1 gene. Chromatin immunohybridization (ChIP) with a Sox4 antibody performed in 32D clone 3 lymphoblasts confirmed binding in a highly conserved area of the Pu.1 upstream control region. An electromobility shift assay (EMSA) is currently pursued. In summary, these results elucidate how the transcription factor Pu.1 is regulated by Sox4 though an upper regulatory element and can play a role in leukemogenesis. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Phosphorylation of Serine114 of the transcription factor ABSCISIC ACID INSENSITIVE 4 is essential for activity

2020 ◽  
Author(s):  
Nadav Eisner ◽  
Tzofia Maymon ◽  
Ester Cancho Sanchez ◽  
Dana Bar-Zvi ◽  
Sagie Brodsky ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
Stress Responses ◽  
Lateral Root ◽  
Map Kinases ◽  
Regulation Of Gene Expression ◽  
List Type ◽  
Lateral Root Development ◽  
Aba Insensitive

AbstractThe transcription factor ABA-INSENSITIVE(ABI)4 has diverse roles in regulating plant growth, including inhibiting germination and reserve mobilization in response to ABA and high salinity, inhibiting seedling growth in response to high sugars, inhibiting lateral root growth, and repressing light-induced gene expression. ABI4 activity is regulated at multiple levels, including gene expression, protein stability, and activation by phosphorylation. Although ABI4 can be phosphorylated at multiple residues by MAPKs, we found that S114 is the preferred site of MPK3. To examine the possible biological role of S114 phosphorylation, we transformed abi4-1 mutant plants with ABI4pro::ABI4 constructs encoding wild type (114S), phosphorylation-null (S114A) or phosphomimetic (S114E) forms of ABI4. Phosphorylation of S114 is necessary for the response to ABA, glucose, salt stress, and lateral root development, where the abi4 phenotype could be complemented by expressing ABI4(114S) or ABI4(S114E) but not ABI4(S114A). Comparison of root transcriptomes in ABA-treated roots of abi4-1 mutant plants transformed with constructs encoding the different phosphorylation-forms of S114 of ABI4 revealed that 85% of the ABI4-regulated genes whose expression pattern could be restored by expressing ABI4(114S) are down-regulated by ABI4. Over half of the ABI4-modulated genes were independent of the phosphorylation state of ABI4; these are enriched for stress responses. Phosphorylation of S114 was required for regulation of 35% of repressed genes, but only 17% of induced genes. The genes whose repression requires the phosphorylation of S114 are mainly involved in embryo and seedling development, growth and differentiation, and regulation of gene expression.HighlightsTranscription factor ABI4 is a substrate of MAP kinases.MPK3 preferentially phosphorylates Serine 114 of ABI4.Phosphorylated Serine 114 of ABI4 is required for the complementation of abi4 mutants.Phosphorylated ABI4 acts primarily as a repressor.

scholarly journals A Soybean bZIP Transcription Factor GmbZIP19 Confers Multiple Biotic and Abiotic Stress Responses in Plant

2020 ◽  
Vol 21 (13) ◽  
pp. 4701
Author(s):  
Qing He ◽  
Hanyang Cai ◽  
Mengyan Bai ◽  
Man Zhang ◽  
Fangqian Chen ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Drought Stress ◽  
Pseudomonas Syringae ◽  
Stress Responses ◽  
Stomatal Closure ◽  
Negative Regulator ◽  
Marker Genes ◽  
Genes Expression ◽  
Salt And Drought Stress ◽  
Salt And Drought Stresses

The basic leucine zipper (bZIP) is a plant-specific transcription factor family that plays crucial roles in response to biotic and abiotic stresses. However, little is known about the function of bZIP genes in soybean. In this study, we isolated a bZIP gene, GmbZIP19, from soybean. A subcellular localization study of GmbZIP19 revealed its nucleus localization. We showed that GmbZIP19 expression was significantly induced by ABA (abscisic acid), JA (jasmonic acid) and SA (salicylic acid), but reduced under salt and drought stress conditions. Further, GmbZIP19 overexpression Arabidopsis lines showed increased resistance to S. sclerotiorum and Pseudomonas syringae associated with upregulated ABA-, JA-, ETH- (ethephon-)and SA-induced marker genes expression, but exhibited sensitivity to salt and drought stresses in association with destroyed stomatal closure and downregulated the salt and drought stresses marker genes’ expression. We generated a soybean transient GmbZIP19 overexpression line, performed a Chromatin immunoprecipitation assay and found that GmbZIP19 bound to promoters of ABA-, JA-, ETH-, and SA-induced marker genes in soybean. The yeast one-hybrid verified the combination. The current study suggested that GmbZIP19 is a positive regulator of pathogen resistance and a negative regulator of salt and drought stress tolerance.

PU.1 Cooperates with SOX4 in Myeloid Cells.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 2633-2633
Author(s):  
Georg Aue ◽  
Yang Du ◽  
Nancy A. Jenkins ◽  
Cynthia E. Dunbar ◽  
Neal G. Copeland
Keyword(s):  
Bone Marrow ◽  
Transcription Factor ◽  
Vector Control ◽  
Myeloid Leukemia ◽  
De Novo ◽  
Bone Marrow Cells ◽  
Myeloid Cells ◽  
P Value ◽  
Mrna Levels ◽  
Wild Type

Abstract Mice that express 20% the normal levels of the Ets transcription factor PU.1 develop AML, unlike mice that express 50% or 80% the normal levels, indicating that PU.1 is a dosage-sensitive tumor suppressor gene. In addition, 3 of 13 AMLs induced by transplanting mice with cells transduced with a Sox4 oncogene-containing retrovirus were found to carry a Sox4 retroviral integration in one PU.1 allele, suggesting that downregulation of PU.1 may cooperate with Sox4 in AML induction. Since the other PU.1 allele remains intact in these AMLs and a 50% decrease in PU.1 expression is not sufficient to induce AML, we hypothesized that Sox4 might further downregulate PU.1 expression in these AMLs. To test this hypothesis, we transfected HL60 cells with an expression vector carrying GFP and Sox4 cDNA or a GFP vector control alone. PU.1 mRNA levels were consistently downregulated 4 to 10 fold in cells transfected with Sox4 cDNA compared to cells transfected with the vector control, confirming that overexpression of Sox4 downregulates PU.1 expression in myeloid cells. The decrease of PU.1 mRNA was observed as early as 8 hours after Sox4 transfection, further suggesting that Sox4 may directly interact with PU.1 in myeloid cells. Consistent with this, analysis of 2 published microarray databases comprising 401 de novo AML patient samples showed that SOX4 expression is significantly negatively correlated with PU.1 expression (coefficient: −0.337, P-value: 1E-07). In order to confirm that downregulation of PU.1 cooperates with Sox4 in AML induction, we infected wild type or PU.1 heterozygous knockout bone marrow cells with the Sox4 retrovirus and then monitored the time of AML development in transplanted mice. Results showed increased penetrance (95%) of myeloid leukemia in mice transplanted with Sox4-infected PU +/– bone marrow compared to mice receiving Sox4-infected wild type marrow (60%). Myeloid leukemia was confirmed by histology in all animals of the Sox4-infected PU +/ cohort while T cell lymphoma was diagnosed in 3 animals of the Sox4 wild type cohort. Together, all experiments support the hypothesis that Sox4 cooperates with the transcription factor PU.1.

scholarly journals The Basic Leucine Zipper Transcription Factor Moatf1 Mediates Oxidative Stress Responses and Is Necessary for Full Virulence of the Rice Blast Fungus Magnaporthe oryzae

2010 ◽  
Vol 23 (8) ◽  
pp. 1053-1068 ◽  
Author(s):  
Min Guo ◽  
Wang Guo ◽  
Yue Chen ◽  
Suomeng Dong ◽  
Xing Zhang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Transcription Factor ◽  
Magnaporthe Oryzae ◽  
Stress Responses ◽  
Rice Blast ◽  
Leucine Zipper ◽  
Blast Disease ◽  
Bzip Transcription Factor ◽  
Wild Type ◽  
Basic Leucine Zipper

Magnaporthe oryzae is the causal agent of rice blast disease, leading to enormous losses of rice production. Here, we characterized a basic leucine zipper (bZIP) transcription factor, Moatf1, in M. oryzae, a homolog of Schizosaccharomyces pombe ATF/CREB that regulates the oxidative stress response. Moatf1 deletion caused retarded vegetative growth of mycelia, and the Moatf1 mutant exhibited higher sensitivity to hydrogen peroxide (H2O2) than did the wild-type strain. The mutant showed severely reduced activity of extracellular enzymes and transcription level of laccases and peroxidases and exhibited significantly reduced virulence on rice cultivar CO-39. On rice leaf sheath, most of the infectious hyphae of the mutant became swollen and displayed restricted growth in primary infected cells. Defense response was strongly activated in plants infected by the mutant. Diamino benzidine staining revealed an accumulation of H2O2 around Moatf1 mutant appressoria and rice cells with Moatf1 hyphae that was absent in the wild type. Inhibition of the plant NADPH oxidase by diphenyleneiodonium prevented host-derived H2O2 accumulation and restored infectious hyphal growth of the mutant in rice cells. Thus, we conclude that Moatf1 is necessary for full virulence of M. oryzae by regulating the transcription of laccases and peroxidases to impair reactive oxygen species–mediated plant defense.

scholarly journals Activation of Transcription of the Human Cytomegalovirus Early UL4 Promoter by the Ets Transcription Factor Binding Element

2000 ◽  
Vol 74 (21) ◽  
pp. 9845-9857 ◽  
Author(s):  
Jiping Chen ◽  
Mark F. Stinski
Keyword(s):  
Transcription Factor ◽  
Steady State ◽  
Human Cytomegalovirus ◽  
Transcriptional Start Site ◽  
Mitogen Activated Protein Kinase ◽  
Viral Gene ◽  
Mrna Levels ◽  
Wild Type ◽  
Nuclear Extracts ◽  
Cellular Transcription

ABSTRACT The human cytomegalovirus (HCMV) early UL4 promoter has served as a useful model for studying the activation of early viral gene expression. Previous transient-transfection experiments detectedcis-acting elements (the NF-Y site and site 2) upstream of the transcriptional start site (L. Huang and M. F. Stinski, J. Virol. 69:7612–7621, 1995). The roles of two of these sites, the NF-Y site and site 2, in the context of the viral genome were investigated further by comparing mRNA levels from the early UL4 promoter in human foreskin fibroblasts infected by recombinant viruses with either wild-type or mutant cis-acting elements. Steady-state mRNA levels from the UL4 promoter with a mutation in the NF-Y site were comparable to that of wild type. A mutation in an Elk-1 site plus putative IE86 protein binding sites decreased the steady-state mRNA levels compared to the wild type at early times after infection. Electrophoretic mobility shift assays and antibody supershifts detected the binding of cellular transcription factor Elk-1 to site 2 DNA with infected nuclear extracts but not with mock-infected nuclear extracts. The role of cellular transcription factors activated by the mitogen activated protein kinase/extracellular signal-regulated kinase pathway in activating transcription from early viral promoters is discussed.

scholarly journals Overexpression of a Malus baccata NAC Transcription Factor Gene MbNAC25 Increases Cold and Salinity Tolerance in Arabidopsis

2020 ◽  
Vol 21 (4) ◽  
pp. 1198 ◽  
Author(s):  
Deguo Han ◽  
Man Du ◽  
Zhengyi Zhou ◽  
Shuang Wang ◽  
Tiemei Li ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Stress Responses ◽  
Apical Meristem ◽  
High Salinity ◽  
Transgenic Arabidopsis ◽  
Wild Type ◽  
Mda Content ◽  
High Salt Stress ◽  
Malus Baccata ◽  
Nac Family

NAC (no apical meristem (NAM), Arabidopsis thaliana transcription activation factor (ATAF1/2) and cup shaped cotyledon (CUC2)) transcription factors play crucial roles in plant development and stress responses. Nevertheless, to date, only a few reports regarding stress-related NAC genes are available in Malus baccata (L.) Borkh. In this study, the transcription factor MbNAC25 in M. baccata was isolated as a member of the plant-specific NAC family that regulates stress responses. Expression of MbNAC25 was induced by abiotic stresses such as drought, cold, high salinity and heat. The ORF of MbNAC25 is 1122 bp, encodes 373 amino acids and subcellular localization showed that MbNAC25 protein was localized in the nucleus. In addition, MbNAC25 was highly expressed in new leaves and stems using real-time PCR. To analyze the function of MbNAC25 in plants, we generated transgenic Arabidopsis plants that overexpressed MbNAC25. Under low-temperature stress (4 °C) and high-salt stress (200 mM NaCl), plants overexpressing MbNAC25 enhanced tolerance against cold and drought salinity conferring a higher survival rate than that of wild-type (WT). Correspondingly, the chlorophyll content, proline content, the activities of antioxidant enzymes superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) were significantly increased, while malondialdehyde (MDA) content was lower. These results indicated that the overexpression of MbNAC25 in Arabidopsis plants improved the tolerance to cold and salinity stress via enhanced scavenging capability of reactive oxygen species (ROS).

scholarly journals StABI5 Involved in the Regulation of Chloroplast Development and Photosynthesis in Potato

2020 ◽  
Vol 21 (3) ◽  
pp. 1068
Author(s):  
Tingting Zhu ◽  
Linxuan Li ◽  
Li Feng ◽  
Maozhi Ren
Keyword(s):  
Transcription Factor ◽  
Stress Responses ◽  
Leucine Zipper ◽  
Carbon Fixation ◽  
Chloroplast Development ◽  
Transgenic Potato ◽  
Basic Leucine Zipper ◽  
Chlorophyll Contents ◽  
Aba Insensitive ◽  
Potato Growth

Abscisic acid (ABA) insensitive 5 (ABI5)—a core transcription factor of the ABA signaling pathway—is a basic leucine zipper transcription factor that plays a key role in the regulation of seed germination and early seedling growth. ABI5 interacts with other phytohormone signals to regulate plant growth and development, and stress responses in Arabidopsis, but little is known about the functions of ABI5 in potatoes. Here, we find that StABI5 is involved in the regulation of chloroplast development and photosynthesis. Genetic analysis indicates that StABI5 overexpression transgenic potato lines accelerate dark-induced leaf yellowing and senescence. The chlorophyll contents of overexpressed StABI5 transgenic potato lines were significantly decreased in comparison to those of wild-type Desiree potatoes under dark conditions. Additionally, the RNA-sequencing (RNA-seq) analysis shows that many metabolic processes are changed in overexpressed StABI5 transgenic potatoes. Most of the genes involved in photosynthesis and carbon fixation are significantly down-regulated, especially the chlorophyll a-b binding protein, photosystem I, and photosystem II. These observations indicate that StABI5 negatively regulates chloroplast development and photosynthesis, and provides some insights into the functions of StABI5 in regard to potato growth.

scholarly journals Potato NAC Transcription Factor StNAC053 Enhances Salt and Drought Tolerance in Transgenic Arabidopsis

2021 ◽  
Vol 22 (5) ◽  
pp. 2568
Author(s):  
Qi Wang ◽  
Cun Guo ◽  
Zhiyuan Li ◽  
Jinhao Sun ◽  
Zhichao Deng ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Drought Stress ◽  
Stress Responses ◽  
Nac Transcription Factor ◽  
Transactivation Domain ◽  
Wild Type ◽  
Gfp Fusion Protein ◽  
Salt And Drought Stress ◽  
Stress Related Genes ◽  
Nac Family

The NAC (NAM, ATAF1/2, and CUC2) transcription factors comprise one of the largest transcription factor families in plants and play important roles in stress responses. However, little is known about the functions of potato NAC family members. Here we report the cloning of a potato NAC transcription factor gene StNAC053, which was significantly upregulated after salt, drought, and abscisic acid treatments. Furthermore, the StNAC053-GFP fusion protein was found to be located in the nucleus and had a C-terminal transactivation domain, implying that StNAC053 may function as a transcriptional activator in potato. Notably, Arabidopsis plants overexpressing StNAC053 displayed lower seed germination rates compared to wild-type under exogenous ABA treatment. In addition, the StNAC053 overexpression Arabidopsis lines displayed significantly increased tolerance to salt and drought stress treatments. Moreover, the StNAC053-OE lines were found to have higher activities of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) under multiple stress treatments. Interestingly, the expression levels of several stress-related genes including COR15A,DREB1A, ERD11, RAB18, ERF5, and KAT2, were significantly upregulated in these StNAC053-overexpressing lines. Taken together, overexpression of the stress-inducible StNAC053 gene could enhance the tolerances to both salt and drought stress treatments in Arabidopsis, likely by upregulating stress-related genes.

scholarly journals Activation of SnRK2 by the Raf-like kinase ARK represents a common mechanism of ABA response in embryophytes

2020 ◽  
Author(s):  
Mousona Islam ◽  
Takumi Inoue ◽  
Mayuka Hiraide ◽  
Nobiza Khatun ◽  
Akida Jahan ◽  
...  
Keyword(s):  
Abiotic Stress ◽  
Stress Responses ◽  
Physcomitrella Patens ◽  
Phosphorylation Site ◽  
Immunoblot Analysis ◽  
Common Mechanism ◽  
Wild Type ◽  
Physiological Characterization ◽  
Upstream Regulator ◽  
Aba Insensitive

ABSTRACTThe Raf-like protein kinase ARK previously identified in the moss Physcomitrella patens acts as an upstream regulator of subgroup III SnRK2, the key regulator of abscisic acid (ABA) and abiotic stress responses. However, the mechanisms underlying activation of ARK by ABA and abiotic stress for the regulation of SnRK2 including the role of ABA receptor-associated group A PP2C (PP2C-A) are not understood. We identified Ser1029 as the phosphorylation site in the activation loop of ARK, which provided a possible mechanism for regulation of its activity. Analysis of transgenic ark lines expressing ARK-GFP with Ser1029-to-Ala mutation indicated that this replacement causes reductions in ABA-induced gene expression, stress tolerance and SnRK2 activity. Immunoblot analysis using an anti-phosphopeptide antibody indicated that ABA treatments rapidly stimulate Ser1029 phosphorylation in wild type. The phosphorylation profile of Ser1029 in ABA-hypersensitive ppabi1 lacking PP2C-A was similar to that in wild type, whereas little Ser1029 phosphorylation was observed in ABA-insensitive ark missense lines. Furthermore, newly isolated ppabi1 ark lines showed ABA-insensitive phenotypes similar to those of ark lines. These results indicate that ARK is a primary activator of SnRK2, preceding negative regulation by PP2C-A in bryophytes, which provides a prototypal mechanism for ABA and abiotic stress-responses in embryophytes.One sentence summaryPhysiological characterization of various moss mutants revealed a common mechanism for phytohormone responses under water deficit in all land plants.

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