Genetic and morphological transformation of rice with the rolA gene from the Ri TL-DNA of Agrobacterium rhizogenes

The rolA gene of Agrobacterium rhizogenes contains in its untranslated leader region a spliceosomal intron, which is spliced in Arabidopsis and in Nicotiana tabacum. Expression under the control of the 35S promoter from cauliflower mosaic virus of a rolA gene derivative defective in splicing still causes alterations of growth in transgenic tobacco plants. Splicing of rolA mRNA is required for efficient expression of the rolA phenotype in vivo. Moreover, splicing is required for efficient in vitro translation of the rolA mRNA. In contrast, expression of a 35S-rolA gene derivative with the ATG initiation codon replaced by ATA does not cause any phenotypical alteration. Mutations leading to amino acid substitutions at positions 37 and 40 of the rolA coding region were isolated as null mutants in Arabidopsis plants transgenic for the rolA gene. However, when expressed in tobacco under the control of the 35S promoter, they cause a rolA phenotype reduced in the expressivity of its traits. The molecular characterization of rolA mutants might be useful for understanding the biochemical function of the rolA protein.

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The spliceosomal intron of the rolA gene of Agrobacterium rhizogenes is a prokaryotic promoter

Molecular Microbiology ◽

10.1046/j.1365-2958.2000.01810.x ◽

2002 ◽

Vol 35 (6) ◽

pp. 1326-1334 ◽

Cited By ~ 20

Author(s):

T. Pandolfini ◽

A. Storlazzi ◽

E. Calabria ◽

R. Defez ◽

A. Spena

Keyword(s):

Agrobacterium Rhizogenes ◽

Spliceosomal Intron ◽

Rola Gene

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The Agrobacterium rhizogenes rolB and rolC promoters are expressed in pericycle cells competent to serve as root initials in transgenic hybrid aspen

Physiologia Plantarum ◽

10.1034/j.1399-3054.1997.1000306.x ◽

1997 ◽

Vol 100 (3) ◽

pp. 456-462 ◽

Cited By ~ 1

Author(s):

Ove Nilsson ◽

Hannele Tuominen ◽

Bjorn Sundberg ◽

Olof Olsson

Keyword(s):

Agrobacterium Rhizogenes ◽

Hybrid Aspen ◽

Pericycle Cells

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Effects of Aging on the Morphology of Rubber-Brass Interfacial Layer

Tire Science and Technology ◽

10.2346/1.3555084 ◽

2011 ◽

Vol 39 (1) ◽

pp. 20-43 ◽

Cited By ~ 7

Author(s):

A. Ashirgade ◽

P. B. Harakuni ◽

W. J. Vanooij

Keyword(s):

Chemical Composition ◽

Interfacial Layer ◽

Secondary Ion Mass Spectrometry ◽

Morphological Changes ◽

Grazing Incidence ◽

Complex Nature ◽

Rubber Compound ◽

Tire Cord ◽

Morphological Transformation ◽

Adhesion Promoter

Abstract Adhesion between rubber compound and brass-plated steel tire cord is crucial in governing the overall performance of tires. The rubber-brass interfacial adhesion is influenced by the chemical composition and thickness of the interfacial layer. It has been shown that the interfacial layer consists mainly of sulfides and oxides of copper and zinc. This paper discusses the effect of changes in the chemical composition and the structure of the interfacial layers due to addition of adhesion promoter resins. Grazing incidence x-ray diffraction (GIXRD) experiments were run on sulfidized polished brass coupons previously bonded to five experimental rubber compounds. It was confirmed that heat and humidity conditions lead to physical and chemical changes of the rubber-steel tire cord interfacial layer, closely related to the degree of rubber-brass adhesion. Morphological transformation of the interfacial layer led to loss of adhesion after aging. The adhesion promoter resins inhibit unfavorable morphological changes in the interfacial layer, thus stabilizing it during aging and prolonging failure. Tire cord adhesion tests illustrated that the one-component resins improved adhesion after aging using a rubber compound with lower cobalt loading. Based on the acquired diffraction profiles, these resins were also found to impede crystallization of the sulfide layer after aging, leading to improved adhesion. Secondary ion mass spectrometry depth profiles and scanning electron microscopy micrographs strongly corroborated the findings from GIXRD. This interfacial analysis adds valuable information to our understanding of the complex nature of the rubber-brass bonding mechanism.

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Myricetin as an Antivirulence Compound Interfering with a Morphological Transformation into Coccoid Forms and Potentiating Activity of Antibiotics against Helicobacter pylori

International Journal of Molecular Sciences ◽

10.3390/ijms22052695 ◽

2021 ◽

Vol 22 (5) ◽

pp. 2695

Author(s):

Paweł Krzyżek ◽

Paweł Migdał ◽

Emil Paluch ◽

Magdalena Karwańska ◽

Alina Wieliczko ◽

...

Keyword(s):

Helicobacter Pylori ◽

Biofilm Formation ◽

Inhibitory Effect ◽

Morphological Transformation ◽

High Tendency ◽

Minimal Inhibitory Concentrations ◽

Coccoid Form ◽

Stomach Diseases ◽

Fold Reduction ◽

H Pylori

Helicobacter pylori, a gastric pathogen associated with a broad range of stomach diseases, has a high tendency to become resistant to antibiotics. One of the most important factors related to therapeutic failures is its ability to change from a spiral to a coccoid form. Therefore, the main aim of our original article was to determine the influence of myricetin, a natural compound with an antivirulence action, on the morphological transformation of H. pylori and check the potential of myricetin to increase the activity of antibiotics against this pathogen. We observed that sub-minimal inhibitory concentrations (sub-MICs) of this compound have the ability to slow down the process of transformation into coccoid forms and reduce biofilm formation of this bacterium. Using checkerboard assays, we noticed that the exposure of H. pylori to sub-MICs of myricetin enabled a 4–16-fold reduction in MICs of all classically used antibiotics (amoxicillin, clarithromycin, tetracycline, metronidazole, and levofloxacin). Additionally, RT-qPCR studies of genes related to the H. pylori morphogenesis showed a decrease in their expression during exposure to myricetin. This inhibitory effect was more strongly seen for genes involved in the muropeptide monomers shortening (csd3, csd6, csd4, and amiA), suggesting their significant participation in the spiral-to-coccoid transition. To our knowledge, this is the first research showing the ability of any compound to synergistically interact with all five antibiotics against H. pylori and the first one showing the capacity of a natural substance to interfere with the morphological transition of H. pylori from spiral to coccoid forms.

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