scholarly journals Effects of BrMYC2/3/4 on Plant Development, Glucosinolate Metabolism, and Sclerotinia sclerotiorum Resistance in Transgenic Arabidopsis thaliana

2021 ◽  
Vol 12 ◽  
Author(s):  
Zhiyan Teng ◽  
Weiwei Zheng ◽  
Youjian Yu ◽  
Seung-Beom Hong ◽  
Zhujun Zhu ◽  
...  
Keyword(s):  
Secondary Metabolites ◽  
Plant Height ◽  
Sclerotinia Sclerotiorum ◽  
Plant Development ◽  
Shoot Elongation ◽  
35S Promoter ◽  
Bhlh Transcription Factor ◽  
Seed Length ◽  
Helix Loop Helix ◽  
Transgenic Lines

MYC2/3/4, known as a basic helix–loop–helix (bHLH) transcription factor, directly activate the genes involved in diverse plant development and secondary metabolites biosynthesis. In this study, we identified and cloned five MYC paralogs (BrMYC2/3-1/3-2/4-1/4-2) from Chinese cabbage (Brassica rapa ssp. pekinensis). In-silico analyses for the physicochemical properties suggested that BrMYC2/3-1/3-2/4-2/4-3 are unstable hydrophobic and acidic proteins, while BrMYC4-1 is an unstable hydrophobic and basic protein. BrMYC2/3/4 belong to the bHLH superfamily and are closely related to AthMYC2/3/4 orthologs that mediate the regulation of various secondary metabolites. It was demonstrated that BrMYC2/3/4-GFP fusion protein localized in the nucleus and expression levels of five BrMYC2/3/4 homologous genes all elevated relative to control (Ctrl). When expressed in Arabidopsis under the control of 35S promoter, each of the BrMYC2/3-1/3-2/4-1/4-2 transgenes differentially influenced root and shoot elongation, vegetative phase change, flowering time, plant height and tiller number after flowering, and seed production. Despite the variation of phenotypes between the transgenic lines, all the lines except for BrMYC4-2 exhibited shorter seed length, less seed weight, higher accumulation of glucosinolates (GSs), and resistance to Sclerotinia sclerotiorum than Ctrl. Notably, BrMYC2 overexpression (OE) line significantly reduced the lengths of root and hypocotyl, seed length, and weight, along with faster bolting time and strikingly higher accumulation of total GSs. Accumulation of GSs at the highest levels in the BrMYC2OE line conferred the highest resistance to S. sclerotiorum. Unlike BrMYC3OE and BrMYC4OE, BrMYC2OE stimulated the growth of plant height after fluorescence. The results of this study point to the BrMYC2 overexpression that may provide a beneficial effect on plant growth and development via plant resistance to the fungal pathogen.

scholarly journals The Nicotiana tabacum Mediator subunit MED25 regulates nicotine biosynthesis through interacting with the basic helix-loop-helix (bHLH) transcription factor NtMYC2s

2021 ◽  
Author(s):  
Ge Bai ◽  
Yong Li ◽  
Da-Hai Yang ◽  
Tao Pang ◽  
Zhi-Yong Fan ◽  
...  
Keyword(s):  
Secondary Metabolites ◽  
Acid Treatment ◽  
Plant Secondary Metabolites ◽  
Bhlh Transcription Factor ◽  
Wild Type ◽  
Helix Loop Helix ◽  
Transgenic Lines ◽  
In The Wild ◽  
Nicotine Biosynthesis

Nicotine is one of the most important secondary metabolites in tobacco, and its biosynthesis can be induced by topping and jasmonic acid treatment. NtMYC2s play pivotal roles in the regulation of nicotine. The mediator server as a bridge betwen the transcription factors and RNA polymerase in order to facilitates transcription and functions in plants. However, the role of mediator in the regulation of nicotine biosynthesis remains unknown. In this study, we firstly identify the NtMED25 through homologous analysis. NtMED25 interacts with NtMYC2s through the MD region. Interestingly, the nicotine content is decreased in the the knock-down transgenic lines of NtMED25, and the expression levels of two nicotine biosynthesis genes, NtQPT2 and NtPMT2, are also reduced when compared with that in the wild-type plants. Furthermore, NtMED25 enhances the binding of NtMYC2a/ NtMYC2b to the promoter of NtPMT2 and NtQPT2, and then facilitates the nicotine biosynthesis. Therefore, our study revealed the function of mediator in the regulation of nicotine, and provide the insight role on the transcriptional regulation of plant secondary metabolites.

scholarly journals OsbHLH073 Negatively Regulates Internode Elongation and Plant Height by Modulating GA Homeostasis in Rice

Plants ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 547
Author(s):  
Jinwon Lee ◽  
Sunok Moon ◽  
Seonghoe Jang ◽  
Sichul Lee ◽  
Gynheung An ◽  
...  
Keyword(s):  
Plant Height ◽  
Molecular Mechanisms ◽  
Agronomic Traits ◽  
Internode Elongation ◽  
Functional Identification ◽  
Dwarf Phenotype ◽  
Quantitative Expression ◽  
Helix Loop Helix ◽  
Transgenic Lines ◽  
Two Hybrid

Internode elongation is one of the key agronomic traits determining a plant’s height and biomass. However, our understanding of the molecular mechanisms controlling internode elongation is still limited in crop plant species. Here, we report the functional identification of an atypical basic helix-loop-helix transcription factor (OsbHLH073) through gain-of-function studies using overexpression (OsbHLH073-OX) and activation tagging (osbhlh073-D) lines of rice. The expression of OsbHLH073 was significantly increased in the osbhlh073-D line. The phenotype of osbhlh073-D showed semi-dwarfism due to deficient elongation of the first internode and poor panicle exsertion. Transgenic lines overexpressing OsbHLH073 confirmed the phenotype of the osbhlh073-D line. Exogenous gibberellic acid (GA3) treatment recovered the semi-dwarf phenotype of osbhlh073-D plants at the seedling stage. In addition, quantitative expression analysis of genes involving in GA biosynthetic and signaling pathway revealed that the transcripts of rice ent-kaurene oxidases 1 and 2 (OsKO1 and OsKO2) encoding the GA biosynthetic enzyme were significantly downregulated in osbhlh073-D and OsbHLH073-OX lines. Yeast two-hybrid and localization assays showed that the OsbHLH073 protein is a nuclear localized-transcriptional activator. We report that OsbHLH073 participates in regulating plant height, internode elongation, and panicle exsertion by regulating GA biosynthesis associated with the OsKO1 and OsKO2 genes.

scholarly journals Overexpression of ThMYC4E Enhances Anthocyanin Biosynthesis in Common Wheat

2019 ◽  
Vol 21 (1) ◽  
pp. 137 ◽  
Author(s):  
Shuo Zhao ◽  
Xingyuan Xi ◽  
Yuan Zong ◽  
Shiming Li ◽  
Yun Li ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Common Wheat ◽  
Anthocyanin Biosynthesis ◽  
Pcr Analysis ◽  
Bhlh Transcription Factor ◽  
Anthocyanin Content ◽  
Metabolome Analysis ◽  
Helix Loop Helix ◽  
Transgenic Lines ◽  
Ethanol Extracts

The basic helix-loop helix (bHLH) transcription factor has been inferred to play an important role in blue and purple grain traits in common wheat, but to date, its overexpression has not been reported. In this study, the bHLH transcription factor ThMYC4E, the candidate gene controlling the blue grain trait from Th. Ponticum, was transferred to the common wheat JW1. The positive transgenic lines displayed higher levels of purple anthocyanin pigments in their grains, leaves and glumes. Stripping the glumes (light treatment) caused white grains to become purple in transgenic lines. RNA-Seq and qRT-PCR analysis demonstrated that the transcript levels of structural genes associated with anthocyanin biosynthesis were higher in transgenic wheat than the wild-type (WT), which indicated that ThMYC4E activated anthocyanin biosynthesis in the transgenic lines. Correspondingly, the anthocyanin contents in grains, roots, stems, leaves and glumes of transgenic lines were higher than those in the WT. Metabolome analysis demonstrated that the anthocyanins were composed of cyanidin and delphinidin in the grains of the transgenic lines. Moreover, the transgenic lines showed higher antioxidant activity, in terms of scavenging DPPH radicals, in the ethanol extracts of their grains. The overexpression of ThMYC4E sheds light on the traits related to anthocyanin biosynthesis in common wheat and provide a new way to improve anthocyanin content.

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.

scholarly journals Comparative Effects of Uniconazole Drench and Spray on Shoot Elongation of Hybrid Lilies

HortScience ◽  
1990 ◽  
Vol 25 (10) ◽  
pp. 1244-1246 ◽  
Author(s):  
J. Jiao ◽  
X. Wang ◽  
M.J. Tsujita
Keyword(s):  
Plant Height ◽  
Plant Development ◽  
Shoot Growth ◽  
Shoot Elongation ◽  
Elongation Rate ◽  
Spray Application ◽  
Flowering Duration ◽  
Height Reduction

Uniconazole was applied as a drench or spray to six hybrid lily (Liliurn sp.) cultivars. Spray application was generally more effective than drench in reducing shoot elongation rate in the first few weeks, and then the efficacy decreased and was less effective than the drench at later stages of plant development. At flowering, a uniconazole drench at 0.1 mg/pot was ineffective for height reduction in `Bravo', `Juliana', and `Sunray' lilies. At higher rates, uniconazole drench was similar to spray in reducing shoot growth in `Bravo' and 306-1 but less effective than spray in `Juliana', `Star Gazer', and `Sunray' lilies. Uniconazole spray reduced plant height at flowering in all the lilies compared to control plants. Days to flower was not affected in `Bravo', `Juliana', and `Sunray' but was increased in `Star Gazer', 306-1, and 306-2 by uniconazole spray treatments. Flowering duration was decreased only in 306-1 by uniconazole spray at 0.2 mg/pot. Chemical name used: (E)-1-(4-chlorophenyl) -4,4 -dimethyl-2-(l,2,4 -triazol-1-yl)-1-penten-3 -ol (uniconazole).

scholarly journals The basic helix-loop-helix transcription factor TabHLH1 increases chlorogenic acid and luteolin biosynthesis in Taraxacum antungense Kitag

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Qun Liu ◽  
Li Li ◽  
Haitao Cheng ◽  
Lixiang Yao ◽  
Jie Wu ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Chlorogenic Acid ◽  
Gene Promoter ◽  
Bhlh Transcription Factor ◽  
Active Components ◽  
Mobility Shift ◽  
Basic Helix Loop Helix ◽  
Helix Loop Helix ◽  
Coa Ligase ◽  
Transgenic Lines

AbstractPolyphenols are the main active components of the anti-inflammatory compounds in dandelion, and chlorogenic acid (CGA) is one of the primary polyphenols. However, the molecular mechanism underlying the transcriptional regulation of CGA biosynthesis remains unclear. Hydroxycinnamoyl-CoA:quinate hydroxycinnamoyl transferase (HQT2) is the last rate-limiting enzyme in chlorogenic acid biosynthesis in Taraxacum antungense. Therefore, using the TaHQT2 gene promoter as a probe, a yeast one-hybrid library was performed, and a basic helix-loop-helix (bHLH) transcription factor, TabHLH1, was identified that shared substantial homology with Gynura bicolor DC bHLH1. The TabHLH1 transcript was highly induced by salt stress, and the TabHLH1 protein was localized in the nucleus. CGA and luteolin concentrations in TabHLH1-overexpression transgenic lines were significantly higher than those in the wild type, while CGA and luteolin concentrations in TabHLH1-RNA interference (RNAi) transgenic lines were significantly lower. Quantitative real-time polymerase chain reaction demonstrated that overexpression and RNAi of TabHLH1 in T. antungense significantly affected CGA and luteolin concentrations by upregulating or downregulating CGA and luteolin biosynthesis pathway genes, especially TaHQT2, 4-coumarate-CoA ligase (Ta4CL), chalcone isomerase (TaCHI), and flavonoid-3′-hydroxylase (TaF3′H). Dual-luciferase, yeast one-hybrid, and electrophoretic mobility shift assays indicated that TabHLH1 directly bound to the bHLH-binding motifs of proTaHQT2 and proTa4CL. This study suggests that TabHLH1 participates in the regulatory network of CGA and luteolin biosynthesis in T. antungense and might be useful for metabolic engineering to promote plant polyphenol biosynthesis.

Co-expression of AGPS and AGPL genes encoded for AGPase from cassava to enhance starch accumulation in transgenic tobacco

2016 ◽  
Vol 14 (2) ◽  
pp. 287-293
Author(s):  
Nguyễn Văn Đoài ◽  
Nguyễn Minh Hồng ◽  
Lê Thu Ngọc ◽  
Nguyễn Thị Thơm ◽  
Nguyễn Đình Trọng ◽  
...  
Keyword(s):  
Transgenic Tobacco ◽  
Higher Plants ◽  
Starch Content ◽  
Genetically Modified Crops ◽  
Starch Accumulation ◽  
35S Promoter ◽  
Effective Strategies ◽  
Plant Expression Vector ◽  
Transgenic Lines ◽  
Cassava Varieties

The AGPase (ADP-Glucose pyrophosphorylase) is one of the ubiquitous enzymes catalyzing the first step in starch biosynthesis. It plays an important role in regulation and adjusts the speed of the entire cycle of glycogen biosynthesis in bacteria and starch in plants. In higher plants, it is a heterotetramer and tetrameric enzyme consisting two large subunits (AGPL) and two small subunits (AGPS) and encoded by two genes. In this paper, both AGPS and AGPL genes were sucessfully isolated from cassava varieties KM140 and deposited in Genbank with accession numbers KU243124 (AGPS) and KU243122 (AGPL), these two genes were fused with P2a and inserted into plant expression vector pBI121 under the control of 35S promoter. The efficient of this construct was tested in transgenic N. tabacum. The presence and expression of AGPS and AGPL in transgenic plants were confirmed by PCR and Western hybridization. The starch content was quantified by the Anthrone method. Transgenic plant analysis indicated that that two targeted genes were expressed simultaneously in several transgenic tobacco lines under the control of CaMV 35S promoter.  The starch contents in 4 analyzed tobacco transgenic lines displays the increase 13-116%  compared to WT plants. These results indicated that the co-expression of AGPS and AGPL is one of effective strategies for enhanced starch production in plant. These results can provide a foundation for developing other genetically modified crops to increase starch accumulation capacity.

Aberrant promoter methylation occurred from multicopy transgene and SU(VAR)3 - 9 homolog 9 (SUVH9) gene in transgenic Nicotiana benthamiana

2012 ◽  
Vol 39 (9) ◽  
pp. 764 ◽  
Author(s):  
Gi-Ho Lee ◽  
Seong-Han Sohn ◽  
Eun-Young Park ◽  
Young-Doo Park
Keyword(s):  
Gene Silencing ◽  
Nicotiana Benthamiana ◽  
Fluorescent Protein ◽  
Cauliflower Mosaic Virus ◽  
Camv 35S Promoter ◽  
35S Promoter ◽  
Camv 35S ◽  
Histone Deacetylase 1 ◽  
Transgenic Lines ◽  
Green Fluorescent

The chemical modification of DNA by methylation is a heritable trait and can be subsequently reversed without altering the original DNA sequence. Methylation can reduce or silence gene expression and is a component of a host’s defence response to foreign nucleic acids. In our study, we employed a plant transformation strategy using Nicotiana benthamiana Domin to study the heritable stability of the introduced transgenes. Through the introduction of the cauliflower mosaic virus (CaMV) 35S promoter and the green fluorescent protein (GFP) reporter gene, we demonstrated that this introduced promoter often triggers a homology-dependent gene-silencing (HDGS) response. These spontaneous transgene-silencing phenomena are due to methylation of the CaMV 35S promoter CAAT box during transgenic plant growth. This process is catalysed by SU(VAR)3–9 homologue 9 (SUVH9), histone deacetylase 1 (HDA1) and domains rearranged methylase 2 (DRM2). In particular, we showed from our data that SUVH9 is the key regulator of methylation activity in epigenetically silenced GFP transgenic lines; therefore, our findings demonstrate that an introduced viral promoter and transgene can be subject to a homology-dependent gene-silencing mechanism that can downregulate its expression and negatively influence the heritable stability of the transgene.

scholarly journals ATBS1-INTERACTING FACTOR 2 Negatively Modulates Pollen Production and Seed Formation in Arabidopsis

2021 ◽  
Vol 12 ◽  
Author(s):  
Yoon Kim ◽  
Sun-Ho Kim ◽  
Dong-Min Shin ◽  
Soo-Hwan Kim
Keyword(s):  
Pollen Grains ◽  
Starch Accumulation ◽  
Bhlh Transcription Factor ◽  
Pollen Production ◽  
Sucrose Transport ◽  
Seed Formation ◽  
Helix Loop Helix ◽  
Knockout Mutants ◽  
Auxin Signalling ◽  
Genes Encoding

ATBS1-INTERACTING FACTOR 2 (AIF2) is a non-DNA-binding basic-helix-loop-helix (bHLH) transcription factor. Here, we demonstrate that AIF2 negatively modulates brassinosteroid (BR)-induced, BRASSINAZOLE RESISTANT 1 (BZR1)-mediated pollen and seed formation. AIF2-overexpressing Arabidopsis plants (AIF2ox) showed defective pollen grains and seed production while two AIF2 knockout mutants, aif2-1 and aif2-1/aif4-1, displayed opposite phenotypes. Genes encoding BZR1-regulated positive factors of seed size determination (SHB1, IKU1, MINI3) were suppressed in AIF2ox and genes for negative factors (AP2 and ARF2) were enhanced. Surprisingly, BZR1-regulated pollen genes such as SPL, MS1, and TDF1 were aberrantly up-regulated in AIF2ox plants. This stage-independent abnormal expression may lead to a retarded and defective progression of microsporogenesis, producing abnormal tetrad microspores and pollen grains with less-effective pollen tube germination. Auxin plays important roles in proper development of flower and seeds: genes for auxin biosynthesis such as TCPs and YUCCAs as well as for positive auxin signalling such as ARFs were suppressed in AIF2ox flowers. Moreover, lipid biosynthesis- and sucrose transport-related genes were repressed, resulting in impaired starch accumulation. Contrarily, sucrose and BR repressed ectopic accumulation of AIF2, thereby increasing silique length and the number of seeds. Taken together, we propose that AIF2 is negatively involved in pollen development and seed formation, and that sucrose- and BR-induced repression of AIF2 positively promotes pollen production and seed formation in Arabidopsis.

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