Characterization of the Sucrose Phosphate Phosphatase (SPP) Isoforms from Arabidopsis thaliana and Role of the S6PPc Domain in Dimerization

Flavonols are the most abundant of all the flavonoids and play pivotal roles in a variety of plants. We isolated a cDNA clone encoding flavonol synthase fromScutellaria baicalensis(SbFLS). The SbFLS cDNA is 1011 bp long, encodes 336 amino acid residues, and belongs to a family of 2-oxoglutarate-dependent dioxygenases. The overall structure ofSbFLSis very similar to that ofArabidopsis thalianaanthocyanidin synthase (AtANS), with aβjelly-roll fold surrounded by tens of short and longα-helices.SbFLSwas constitutively expressed in the roots, stems, leaves, and flowers, with particularly high expression in the roots and flowers. SbFLS transcript levels in the roots were 376-, 70-, and 2.5-fold higher than in the leaves, stems, and flowers. The myricetin content was significantly higher than that of kaempferol and quercetin. Therefore, we suggest that SbFLS mediates flavonol formation in the different organs ofS. baicalensis. Our study may contribute to the knowledge of the role of FLS inS. baicalensis.

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Characterization of Arabidopsis thaliana mutant ror-1 (roscovitine-resistant) and its utilization in understanding of the role of cytokinin N-glucosylation pathway in plants

Plant Growth Regulation ◽

10.1007/s10725-010-9467-8 ◽

2010 ◽

Vol 61 (3) ◽

pp. 231-242 ◽

Cited By ~ 15

Author(s):

Somya Dwivedi ◽

Radomira Vanková ◽

Vaclav Motyka ◽

Carmen Herrera ◽

Eva Zizkova ◽

...

Keyword(s):

Arabidopsis Thaliana

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Characterization of two cDNAs that encode MAP kinase homologues in Arabidopsis thaliana and analysis of the possible role of auxin in activating such kinase activities in cultured cells

The Plant Journal ◽

10.1046/j.1365-313x.1994.5010111.x ◽

1994 ◽

Vol 5 (1) ◽

pp. 111-122 ◽

Cited By ~ 134

Author(s):

Tsuyoshi Mizoguchi ◽

Yukiko Gotoh ◽

Eisuke Nishida ◽

Kazuko Yamaguchi-Shinozaki ◽

Nobuaki Hayashida ◽

...

Keyword(s):

Arabidopsis Thaliana ◽

Map Kinase ◽

Cultured Cells

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Characterization of male-sterile Arabidopsis thaliana mutants exhibiting altered tapetum development

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100085344 ◽

1991 ◽

Vol 49 ◽

pp. 208-209

Author(s):

C. S. Bricker ◽

N. Smith-Huerta ◽

C. A. Makaroff

Keyword(s):

Arabidopsis Thaliana ◽

Male Sterility ◽

Insertional Mutagenesis ◽

Molecular Evidence ◽

Growth Substances ◽

Microspore Development ◽

Male Sterile ◽

Molecular Signals

The tapetum is the tissue in the anther that is in closest contact with the developing microspores. It consists of large and frequently multinucleate, richly cytoplasmic cells that provide most of the nutrients and growth substances necessary for the developing microspore. A great deal of our knowledge on the tapetum has come from studies on malesterile mutants. We are using T-DNA insertional mutants of Arabidopsis thaliana to identify, isolate and characterize the genes that control the differentiation of the tapetum. As a first step we have identified those mutants that exhibit the sporogenous type of male sterility (relatively normal stamen development but alterations in microsporogenesis). Further analyses have identified those mutants that exhibit alterations in tapetum development that have resulted from insertional mutagenesis by the T-DNA. Through the analysis of these mutants we hope to identify the molecular signals that regulate tapetal tissue differentiation and provide molecular evidence on the role of the tapetum in microspore development.

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Differential Expression of Fungal Genes Determines the Lifestyle of Plectosphaerella Strains During Arabidopsis thaliana Colonization

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-03-20-0057-r ◽

2020 ◽

Vol 33 (11) ◽

pp. 1299-1314 ◽

Cited By ~ 1

Author(s):

Antonio Muñoz-Barrios ◽

Sara Sopeña-Torres ◽

Brisa Ramos ◽

Gemma López ◽

Irene del Hierro ◽

...

Keyword(s):

Arabidopsis Thaliana ◽

In Planta ◽

Necrotrophic Fungi ◽

Pathogenesis Related ◽

Nonpathogenic Strain ◽

Genes Encoding ◽

Fungal Genes ◽

Growth Adaptation

The fungal genus Plectosphaerella comprises species and strains with different lifestyles on plants, such as P. cucumerina, which has served as model for the characterization of Arabidopsis thaliana basal and nonhost resistance to necrotrophic fungi. We have sequenced, annotated, and compared the genomes and transcriptomes of three Plectosphaerella strains with different lifestyles on A. thaliana, namely, PcBMM, a natural pathogen of wild-type plants (Col-0), Pc2127, a nonpathogenic strain on Col-0 but pathogenic on the immunocompromised cyp79B2 cyp79B3 mutant, and P0831, which was isolated from a natural population of A. thaliana and is shown here to be nonpathogenic and to grow epiphytically on Col-0 and cyp79B2 cyp79B3 plants. The genomes of these Plectosphaerella strains are very similar and do not differ in the number of genes with pathogenesis-related functions, with the exception of secreted carbohydrate-active enzymes (CAZymes), which are up to five times more abundant in the pathogenic strain PcBMM. Analysis of the fungal transcriptomes in inoculated Col-0 and cyp79B2 cyp79B3 plants at initial colonization stages confirm the key role of secreted CAZymes in the necrotrophic interaction, since PcBMM expresses more genes encoding secreted CAZymes than Pc2127 and P0831. We also show that P0831 epiphytic growth on A. thaliana involves the transcription of specific repertoires of fungal genes, which might be necessary for epiphytic growth adaptation. Overall, these results suggest that in-planta expression of specific sets of fungal genes at early stages of colonization determine the diverse lifestyles and pathogenicity of Plectosphaerella strains.

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Characterization of the Binding of Diarrheagenic Strains of E. coli to Plant Surfaces and the Role of Curli in the Interaction of the Bacteria with Alfalfa Sprouts

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-18-1235 ◽

2005 ◽

Vol 18 (11) ◽

pp. 1235-1242 ◽

Cited By ~ 69

Author(s):

Cecelia Jeter ◽

Ann G. Matthysse

Keyword(s):

Escherichia Coli ◽

Arabidopsis Thaliana ◽

No Reduction ◽

E Coli ◽

Diarrheagenic Escherichia Coli ◽

Alfalfa Sprouts ◽

Plant Surfaces ◽

Seed Coats

Diarrheagenic Escherichia coli were able to bind to plant surfaces, including alfalfa sprouts and open seed coats, and tomato and Arabidopsis thaliana seedlings incubated in water. The characteristics of the binding differed with the bacterial strain examined. Laboratory K12 strains of E. coli failed to show significant binding to any of the plant surfaces examined, suggesting that some of the genes present and expressed in pathogenic strains and absent or unexpressed in K12 strains may be required for binding to plants. When a plasmid carrying the mlrA gene (a positive regulator of curli biosynthesis) or a plasmid carrying the operons that encode the synthesis of curli (csgA-G) was introduced into K12 strains, the bacteria acquired the ability to bind to sprouts. CsgA mutants of an avian pathogenic E. coli and an O157:H7 strain showed no reduction in their ability to bind to sprouts. Thus, the production of curli appears to be sufficient to allow K12 strains to bind, but curli are not necessary for the binding of pathogenic strains, suggesting that pathogenic strains may have more than one mechanism for binding to plant surfaces.

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Digital x-ray mapping of nanometer-size supported bimetallic catalysts

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100104716 ◽

1988 ◽

Vol 46 ◽

pp. 530-531

Author(s):

L. T. Germinario

Keyword(s):

Background Radiation ◽

Metal Cluster ◽

Single Element ◽

Beam Diameter ◽

X Rays ◽

X Ray ◽

Major Interest ◽

Induced Changes

Understanding the role of metal cluster composition in determining catalytic selectivity and activity is of major interest in heterogeneous catalysis. The electron microscope is well established as a powerful tool for ultrastructural and compositional characterization of support and catalyst. Because the spatial resolution of x-ray microanalysis is defined by the smallest beam diameter into which the required number of electrons can be focused, the dedicated STEM with FEG is the instrument of choice. The main sources of errors in energy dispersive x-ray analysis (EDS) are: (1) beam-induced changes in specimen composition, (2) specimen drift, (3) instrumental factors which produce background radiation, and (4) basic statistical limitations which result in the detection of a finite number of x-ray photons. Digital beam techniques have been described for supported single-element metal clusters with spatial resolutions of about 10 nm. However, the detection of spurious characteristic x-rays away from catalyst particles produced images requiring several image processing steps.

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