scholarly journals Molecular Characterization of Auxin Efflux Carrier- ABCB1 in hexaploid wheat

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Amita Mohan ◽  
Amandeep K. Dhaliwal ◽  
Ragupathi Nagarajan ◽  
Kulvinder S. Gill
Keyword(s):  
Promoter Region ◽  
Sequence Similarity ◽  
Regulatory Element ◽  
Long Distance ◽  
Long Distance Transport ◽  
Response Differentiation ◽  
Cell Tissue ◽  
Seed Width ◽  
Auxin Efflux Carrier

AbstractAuxin is an important phytohormone that regulates response, differentiation, and development of plant cell, tissue, and organs. Along with its local production, long-distance transport coordinated by the efflux/influx membrane transporters is instrumental in plant development and architecture. In the present study, we cloned and characterized a wheat (Triticum aestivum) auxin efflux carrier ABCB1. The TaABCB1 was physically localized to the proximal 15% of the short arm of wheat homoeologous group 7 chromosomes. Size of the Chinese spring (CS) homoeologs genomic copies ranged from 5.3–6.2 kb with the 7A copy being the largest due to novel insertions in its third intron. The three homoeologous copies share 95–97% sequence similarity at the nucleotide, 98–99% amino acid, and overall Q-score of 0.98 at 3-D structure level. Though detected in all analyzed tissues, TaABCB1 predominantly expressed in the meristematic tissues likely due to the presence of meristem-specific activation regulatory element identified in the promoter region. RNAi plants of TaABCB1 gene resulted in reduced plant height and increased seed width. Promoter analysis revealed several responsive elements detected in the promoter region including that for different hormones as auxin, gibberellic acid, jasmonic acid and abscisic acid, light, and circadian regulated elements.

Characterization of a notochord-specific enhancer from the Brachyury promoter region of the ascidian, Ciona intestinalis

Development ◽  
1997 ◽  
Vol 124 (3) ◽  
pp. 589-602 ◽  
Author(s):  
J.C. Corbo ◽  
M. Levine ◽  
R.W. Zeller
Keyword(s):  
Promoter Region ◽  
Regulatory Element ◽  
Ciona Intestinalis ◽  
Notch Signaling Pathway ◽  
Negative Control ◽  
Paraxial Mesoderm ◽  
Regulatory Mechanisms ◽  
Lacz Reporter ◽  
Recognition Sequence

We present evidence that the embryo of the ascidian, Ciona intestinalis, is an easily manipulated system for investigating the establishment of basic chordate tissues and organs. Ciona has a small genome, and simple, well-defined embyronic lineages. Here, we examine the regulatory mechanisms underlying the differentiation of the notochord. Particular efforts center on the regulation of a notochord-specific Ciona Brachyury gene (Ci-Bra). An electroporation method was devised for the efficient incorporation of transgenic DNA into Ciona embryos. This method permitted the identification of a minimal, 434 bp enhancer from the Ci-Bra promoter region that mediates the notochord-restricted expression of both GFP and lacZ reporter genes. This enhancer contains a negative control region that excludes Ci-Bra expression from inappropriate embryonic lineages, including the trunk mesenchyme and tail muscles. Evidence is presented that the enhancer is activated by a regulatory element which is closely related to the recognition sequence of the Suppressor of Hairless transcription factor, thereby raising the possibility that the Notch signaling pathway plays a role in notochord differentiation. We discuss the implications of this analysis with regard to the evolutionary conservation of integrative enhancers, and the subdivision of the axial and paraxial mesoderm in vertebrates.

scholarly journals The mouse androgen receptor. Functional analysis of the protein and characterization of the gene

1991 ◽  
Vol 278 (1) ◽  
pp. 269-278 ◽  
Author(s):  
P W Faber ◽  
A King ◽  
H C J van Rooij ◽  
A O Brinkmann ◽  
N J de Both ◽  
...  
Keyword(s):  
Androgen Receptor ◽  
Reporter Gene ◽  
Hela Cells ◽  
Transcription Initiation ◽  
Promoter Region ◽  
Sequence Similarity ◽  
Dependent Manner ◽  
S1 Nuclease ◽  
Isolation And Characterization

Screening a mouse genomic DNA library with human androgen-receptor (hAR) cDNA probes resulted in the isolation and characterization of eight genomic fragments that contain the eight exons of the mouse androgen-receptor (mAR) gene. On the basis of similarity to the hAR gene, the nucleotide sequences of the protein-coding parts of the exons as well as the sequences of the intron/exon boundaries were determined. An open reading frame (ORF) of 2697 nucleotides, which can encode an 899-amino-acid protein, could be predicted. The structure of the mAR ORF was confirmed by sequence analysis of mAR cDNA fragments, which were obtained by PCR amplification of mouse testis cDNA, using mAR specific primers. A eukaryotic mAR expression vector was constructed and mAR was transiently expressed in COS-1 cells. The expressed protein was shown by Western blotting to be identical in size with the native mAR. Co-transfection of HeLa cells with the mAR expression plasmid and an androgen-responsive chloramphenicol acetyltransferase (CAT) reporter-gene construct showed mAR to be able to trans-activate the androgen-responsive promoter in a ligand-dependent manner. Transcription-initiation sites of the mAR gene were identified by S1-nuclease protection experiments, and the functional activity of the promoter region was determined by transient expression of mAR promoter-CAT-reporter-gene constructs in HeLa cells. Structural analysis revealed the promoter of the mAR gene to be devoid of TATA/CCAAT elements. In addition, the promoter region is not remarkably (G + C)-rich. Potential promoter elements consist of a consensus Sp1 binding sequence and a homopurine stretch. The polyadenylation sites of mAR mRNA were identified by sequence similarity to the corresponding sites in the hAR mRNA.

scholarly journals A Tobacco Syringe Agroinfiltration-Based Method for a Phytohormone Transporter Activity Assay Using Endogenous Substrates

2021 ◽  
Vol 12 ◽  
Author(s):  
Jiangzhe Zhao ◽  
Min Ju ◽  
Jiayun Qian ◽  
Mengyuan Zhang ◽  
Ting Liu ◽  
...  
Keyword(s):  
Stress Responses ◽  
Large Scale ◽  
Functional Characterization ◽  
Endogenous Hormones ◽  
Activity Assay ◽  
Long Distance ◽  
Multiple Substrates ◽  
Long Distance Transport ◽  
Endogenous Substrates

Phytohormones are a group of small chemical molecules that play vital roles in plant development, metabolism, and stress responses. Phytohormones often have distinct biosynthesis and signaling perception sites, requiring long- or short-distance transportation. Unlike biosynthesis and signal transduction, phytohormone transport across cells and organs is poorly understood. The transporter activity assay is a bottleneck for the functional characterization of novel phytohormone transporters. In the present study, we report a tobacco syringe agroinfiltration and liquid chromatography tandem mass spectrometry (TSAL)-based method for performing a phytohormone transporter activity assay using endogenous hormones present in tobacco (Nicotiana benthamiana) leaves. A transporter activity assay using this method does not require isotope-labeled substrates and can be conveniently performed for screening multiple substrates by using endogenous hormones in tobacco leaves. The transporter activities of three known hormone transporters, namely AtABCG25 for abscisic acid, AtABCG16 for jasmonic acid, and AtPUP14 for cytokinin, were all successfully validated using this method. Using this method, cytokinins were found to be the preferred substrates of an unknown maize (Zea mays) transporter ZmABCG43. ZmABCG43 transporter activities toward cytokinins were confirmed in a cytokinin long-distance transport mutant atabcg14 through gene complementation. Thus, the TSAL method has the potential to be used for basic substrate characterization of novel phytohormone transporters or for the screening of novel transporters for a specific phytohormone on a large scale.

The Fine Structure of Phloem Cells

1985 ◽  
Vol 43 ◽  
pp. 632-635
Author(s):  
James Cronshaw
Keyword(s):  
Structural Studies ◽  
High Concentration ◽  
Long Distance ◽  
Phloem Tissue ◽  
Sieve Elements ◽  
Long Distance Transport ◽  
P Protein ◽  
Companion Cells ◽  
Electron Microscopical ◽  
Distance Transport

Long distance transport in plants takes place in phloem tissue which has characteristic cells, the sieve elements. At maturity these cells have sieve areas in their end walls with specialized perforations. They are associated with companion cells, parenchyma cells, and in some species, with transfer cells. The protoplast of the functioning sieve element contains a high concentration of sugar, and consequently a high hydrostatic pressure, which makes it extremely difficult to fix mature sieve elements for electron microscopical observation without the formation of surge artifacts. Despite many structural studies which have attempted to prevent surge artifacts, several features of mature sieve elements, such as the distribution of P-protein and the nature of the contents of the sieve area pores, remain controversial.

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