scholarly journals Formation of α- and β-Cembratriene-Diols in Tobacco (Nicotiana tabacum L.) Is Regulated by Jasmonate-Signaling Components via Manipulating Multiple Cembranoid Synthetic Genes

Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2511 ◽  
Author(s):  
Jinkai Sui ◽  
Chunkai Wang ◽  
Xiaofeng Liu ◽  
Ning Fang ◽  
Yanhua Liu ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Regulatory Mechanism ◽  
Critical Role ◽  
Receptor Protein ◽  
Myb Transcription Factor ◽  
Bhlh Transcription Factor ◽  
Gene Encoding ◽  
Synthetic Genes ◽  
Nicotiana Tabacum L ◽  
Signaling Components

Cembranoids are a group of natural diterpenoid compounds with pharmaceutical potentials, and the cembratriene-diols produced by Nicotiana (tobacco) species display activities in anti-nicotine addiction and neuron protection. Although the enzymes catalyzing cembratriene-diols’ formation in tobacco have been investigated, the regulatory mechanism underlying this physiological process remains unknown. This study has investigated the roles of phytohormone jasmonic acid (JA) in regulating cembratriene-diol formation in N. tabacum cv. TN90 and found that JA and COI1, the receptor protein of the bioactive derivative of JA (i.e., JA-Ile), display critical roles in regulating cembratriene-diols’ formation and the expression of cembranoid synthetic genes CBTS, P450 and NtLTP1. Further studies showed that over-expressing either the gene encoding bHLH transcription factor MYC2a or that encoding MYB transcription factor MYB305 could upregulate the cembranoid synthetic genes and enhance the cembranoid production in plants with dysfunction of COI1. Further studies suggest that COI1 and its downstream regulators MYC2a and MYB305 also modulate the trichome secretion, which is correlated with cembranoid formation. Taken together, this study has demonstrated a critical role of JA-signaling components in governing the cembratriene-diol formation and the transcription of cembratriene-diol synthetic genes in tobacco. Findings in this study are of great importance to reveal the molecular regulatory mechanism underlying cembranoid synthesis.

scholarly journals Conserved and non-conserved functions of the rice homologs of the Arabidopsis trichome initiation-regulating MBW complex proteins

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Kaijie Zheng ◽  
Xutong Wang ◽  
Yating Wang ◽  
Shucai Wang
Keyword(s):  
Transcription Factor ◽  
Anthocyanin Biosynthesis ◽  
Transcriptional Activator ◽  
Myb Transcription Factor ◽  
Bhlh Transcription Factor ◽  
Seed Color ◽  
Transcription Activator ◽  
Root Hair Formation ◽  
Protoplast Transfection ◽  
Mbw Complex

Abstract Background Trichome initiation in Arabidopsis is regulated by a MYB-bHLH-WD40 (MBW) transcriptional activator complex formed by the R2R3 MYB transcription factor GLABRA1 (GL1), MYB23 or MYB82, the bHLH transcription factor GLABRA3 (GL3), ENHANCER OF GLABRA3 (EGL3) or TRANSPARENT TESTA8 (TT8), and the WD40-repeat protein TRANSPARENT TESTA GLABRA1 (TTG1). However, the functions of the rice homologs of the MBW complex proteins remained uncharacterized. Results Based on amino acid sequence identity and similarity, and protein interaction prediction, we identified OsGL1s, OsGL3s and OsTTG1s as rice homologs of the MBW complex proteins. By using protoplast transfection, we show that OsGL1D, OsGL1E, OsGL3B and OsTTG1A were predominantly localized in the nucleus, OsGL3B functions as a transcriptional activator and is able to interact with GL1 and TTG1. By using yeast two-hybrid and protoplast transfection assays, we show that OsGL3B is able to interact with OsGL1E and OsTTG1A, and OsGL1E and OsTTG1A are also able to interact with GL3. On the other hand, we found that OsGL1D functions as a transcription activator, and it can interact with GL3 but not OsGL3B. Furthermore, our results show that expression of OsTTG1A in the ttg1 mutant restored the phenotypes including alternations in trichome and root hair formation, seed color, mucilage production and anthocyanin biosynthesis, indicating that OsTTG1A and TTG1 may have similar functions. Conclusion These results suggest that the rice homologs of the Arabidopsis MBW complex proteins are able to form MBW complexes, but may have conserved and non-conserved functions.

scholarly journals The Transcription Factor Twist1 Limits T Helper 17 and T Follicular Helper Cell Development by Repressing the Gene Encoding the Interleukin-6 Receptor α Chain

2013 ◽  
Vol 288 (38) ◽  
pp. 27423-27433 ◽  
Author(s):  
Duy Pham ◽  
Crystal C. Walline ◽  
Kristin Hollister ◽  
Alexander L. Dent ◽  
Janice S. Blum ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Critical Role ◽  
Cell Development ◽  
Receptor Expression ◽  
Helper Cell ◽  
T Helper 17 ◽  
Gene Encoding ◽  
Extracellular Milieu ◽  
Follicular Helper ◽  
T Follicular Helper Cell

Cytokine responsiveness is a critical component of the ability of cells to respond to the extracellular milieu. Transcription factor-mediated regulation of cytokine receptor expression is a common mode of altering responses to the external environment. We identify the transcription factor Twist1 as a component of a STAT3-induced feedback loop that controls IL-6 signals by directly repressing Il6ra. Human and mouse T cells lacking Twist1 have an increased ability to differentiate into Th17 cells. Mice with a T cell-specific deletion of Twist1 demonstrate increased Th17 and T follicular helper cell development, early onset experimental autoimmune encephalomyelitis, and increased antigen-specific antibody responses. Thus, Twist1 has a critical role in limiting both cell-mediated and humoral immunity.

Novel Role of the TAL1/SCL Transcription Factor in Murine Monocytopoiesis.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1376-1376
Author(s):  
Soumyadeep Dey ◽  
David J. Curtis ◽  
Stephen Jane ◽  
Stephen J. Brandt
Keyword(s):  
Transcription Factor ◽  
Real Time ◽  
Real Time Pcr ◽  
Mononuclear Cells ◽  
Critical Role ◽  
Pcr Analysis ◽  
Bhlh Transcription Factor ◽  
Lacz Gene ◽  
Macrophage Differentiation ◽  
In Cells

Abstract The basic helix-loop-helix (bHLH) transcription factor TAL1/SCL plays a critical role in hematopoiesis and vascular remodeling. A mouse Tal1 cDNA was first cloned from a bone marrow (BM) macrophage cDNA library, and we and others observed expression ofTal1 protein by BM mononuclear cells. To characterize Tal1 expression during monocyte/macrophage differentiation, we isolated common myeloid precursors (CMPs) from BM of 3-5 week old C57BL/6J mice and induced them to terminally differentiate according to a published method (Genes & Dev., 16:1721, 2002). Using real-time PCR analysis,Tal1 mRNA was expressed in a biphasic pattern from CMP to post-mitotic macrophage, including lipopolysaccharide- and interferon-ã-activated macrophages. To elucidate Tal1’sfunctions in murine monocytopoiesis we deleted the Tal1 gene in murine BM monocytes and monocytic precursors in culture. To that end, C57BL/6 mice with loxP sequences flanking the third coding exon of Tal1 were bred with C57BL/6 mice with a lacZ gene replacing Tal1 coding exons 1, 2, and 3. Tal1fl/fl/lacZ progeny were identified by PCR genotyping, and BM mononuclear cells were cultured with mouse interleukin-3 and macrophage colony-stimulating factor (M-CSF). To render the cells Tal1-null, Cre coding sequences were introduced with the MSCV-GFP retroviral vector and GFP-positive cells were then sorted and cultured with M-CSF alone. Real-time PCR analysis showed near-total abolition of Tal1 mRNA expression in Cre-transduced relative to vector-transduced cells. Gene expression analysis for other transcripts showed an approximately 4-foldreduction in Gata2 expression over the same culture period but no difference in Aml1,PU.1, Csfr1, Msr1 (mouse scavenger receptor), Cd68, or Il6ra. Biologically, the most significant effect of Tal1 knockout was on cell number, which increased by 80% in control cells but not at all in Tal1-null cells. Transduction of wild-type BM monocytes with MSCV-GFP-Cre (or the parental MSCV-GFP) vector had no effect on cell proliferation, precluding any nonspecific or toxic effect of Cre (or retroviral infection) in this cell type. Dye dilution analysis of virus-transduced cells with the fluorescent membrane-intercalating dye PKH26 revealed a delay and absolute reduction in proliferation of Tal1-null compared to control cells. In contrast, little or no difference was noted in annexin V staining ofTal1-null compared to heterozygous knockout (knock-in) cells, indicating a lack of effect on apoptosis. Finally, serial analysis of CD31 and Ly6c expression in differentiating Tal1hemizygous and nullizygous BM monocytes showed that loss of Tal1 caused a slight acceleration in terminal monocyte-macrophage differentiation. In summary, these studies confirm our earlier finding that the Tal1 gene is expressed in differentiating mouse BMmonocytes. In addition, they reveal a novel function of this bHLH transcription factor in proliferation of murine monocyte/macrophage precursors. Finally, they place Tal1upstream of Gata2 in cells of this lineage.

scholarly journals CmMYB#7, an R3 MYB transcription factor, acts as a negative regulator of anthocyanin biosynthesis in chrysanthemum

2019 ◽  
Vol 70 (12) ◽  
pp. 3111-3123 ◽  
Author(s):  
Lili Xiang ◽  
Xiaofen Liu ◽  
Heng Li ◽  
Xueren Yin ◽  
Donald Grierson ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Transcription Factors ◽  
Binding Site ◽  
Transient Expression ◽  
Regulatory Mechanism ◽  
Anthocyanin Biosynthesis ◽  
Expression Patterns ◽  
Negative Regulator ◽  
Myb Transcription Factor ◽  
Anthocyanin Content

Abstract ‘Jimba’, a well-known white flowered chrysanthemum cultivar, occasionally and spontaneously produces red colored petals under natural cultivation, but there is little information about the molecular regulatory mechanism underlying this process. We analysed the expression patterns of 91 MYB transcription factors in ‘Jimba’ and ‘Turning red Jimba’ and identified an R3 MYB, CmMYB#7, whose expression was significantly decreased in ‘Turning red Jimba’ compared with ‘Jimba’, and confirmed it is a passive repressor of anthocyanin biosynthesis. CmMYB#7 competed with CmMYB6, which together with CmbHLH2 is an essential component of the anthocyanin activation complex, for interaction with CmbHLH2 through the bHLH binding site in the R3 MYB domain. This reduced binding of the CmMYB6–CmbHLH2 complex and inhibited its ability to activate CmDFR and CmUFGT promoters. Moreover, using transient expression assays we demonstrated that changes in the expression of CmMYB#7 accounted for alterations in anthocyanin content. Taken together, our findings illustrate that CmMYB#7 is a negative regulator of anthocyanin biosynthesis in chrysanthemum.

scholarly journals Diversification and Molecular Evolution of ATOH8, a Gene Encoding a bHLH Transcription Factor

PLoS ONE ◽  
2011 ◽  
Vol 6 (8) ◽  
pp. e23005 ◽  
Author(s):  
Jingchen Chen ◽  
Fangping Dai ◽  
Ajeesh Balakrishnan-Renuka ◽  
Florian Leese ◽  
Werner Schempp ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Molecular Evolution ◽  
Bhlh Transcription Factor ◽  
Gene Encoding

scholarly journals Novel spoIIE Mutation That Causes Uncompartmentalized σF Activation in Bacillus subtilis

2003 ◽  
Vol 185 (5) ◽  
pp. 1590-1598 ◽  
Author(s):  
David W. Hilbert ◽  
Patrick J. Piggot
Keyword(s):  
Transcription Factor ◽  
Bacillus Subtilis ◽  
Mother Cell ◽  
Critical Role ◽  
Asymmetric Division ◽  
Small Subset ◽  
Gene Encoding ◽  
Specific Transcription Factor ◽  
Fold Reduction ◽  
Optimal Efficiency

ABSTRACT During sporulation, Bacillus subtilis undergoes an asymmetric division that results in two cells with different fates, the larger mother cell and the smaller forespore. The protein phosphatase SpoIIE, which is required for activation of the forespore-specific transcription factor σF, is also required for optimal efficiency and timing of asymmetric division. We performed a genetic screen for spoIIE mutants that were impaired in sporulation but not σF activity and isolated a strain with the mutation spoIIEV697A. The mutant exhibited a 10- to 40-fold reduction in sporulation and a sixfold reduction in asymmetric division compared to the parent. Transcription of the σF-dependent spoIIQ promoter was increased more than 10-fold and was no longer confined to the forespore. The excessive σF activity persisted even when asymmetric division was prevented. Disruption of spoIIGB did not restore asymmetric division to the spoIIEV697A mutant, indicating that the deficiency is not a consequence of predivisional activation of the mother cell-specific transcription factor σE. Deletion of the gene encoding σF (spoIIAC) restored asymmetric division; however, a mutation that dramatically reduced the number of promoters responsive to σF, spoIIAC561 (spoIIACV233 M), failed to do so. This result suggests that the block is due to expression of one of the small subset of σF-dependent genes expressed in this background or to unregulated interaction of σF with some other factor. Our results indicate that regulation of SpoIIE plays a critical role in coupling asymmetric division to σF activation in order to ensure proper spatial and temporal expression of forespore-specific genes.

scholarly journals Increased Leaf Nicotine Content by Targeting Transcription Factor Gene Expression in Commercial Flue-Cured Tobacco (Nicotiana tabacum L.)

Genes ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 930 ◽  
Author(s):  
Hai Liu ◽  
Tatyana I. Kotova ◽  
Michael P. Timko
Keyword(s):  
Transcription Factor ◽  
Nicotiana Tabacum ◽  
Gene Promoter ◽  
Bhlh Transcription Factor ◽  
Helix Loop Helix ◽  
Nicotiana Tabacum L ◽  
Meja Treatment ◽  
Transgenic Lines ◽  
Nicotine Biosynthesis ◽  
High Level

Nicotine, the most abundant pyridine alkaloid in cultivated tobacco (Nicotiana tabacum L.), is a potent inhibitor of insect and animal herbivory and a neurostimulator of human brain function. Nicotine biosynthesis is controlled developmentally and can be induced by abiotic and biotic stressors via a jasmonic acid (JA)-mediated signal transduction mechanism involving members of the APETALA 2/ethylene-responsive factor (AP2/ERF) and basic helix-loop-helix (bHLH) transcription factor (TF) families. AP2/ERF and bHLH TFs work combinatorically to control nicotine biosynthesis and its subsequent accumulation in tobacco leaves. Here, we demonstrate that overexpression of the tobacco NtERF32, NtERF221/ORC1, and NtMYC2a TFs leads to significant increases in nicotine accumulation in T2 transgenic K326 tobacco plants before topping. Up to 9-fold higher nicotine production was achieved in transgenics overexpressing NtERF221/ORC1 under the control of a constitutive GmUBI3 gene promoter compared to wild-type plants. The constitutive 2XCaMV35S promoter and a novel JA-inducible 4XGAG promoter were less effective in driving high-level nicotine formation. Methyljasmonic acid (MeJA) treatment further elevated nicotine production in all transgenic lines. Our results show that targeted manipulation of NtERF221/ORC1 is an effective strategy for elevating leaf nicotine levels in commercial tobacco for use in the preparation of reduced risk tobacco products for smoking replacement therapeutics.

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