Genetic analysis of chlorophyll-deficient somaclonal variants in rye

Albino plants have been observed among regenerated plants from immature embryo calluses in four cultivars of rye. The frequency of albino plants was very similar between the plants regenerated from embryogenic (8.78%) or organogenic (12.06%) cultures. However, these frequencies varied widely between cultivars (from 0 to 23.46%). On the other hand, 12% of the green regenerated plants segregated in their progeny plants with chlorophyll deficiencies, and most of these mutations segregated as we can expect a Mendelian trait to do. The behaviour of the regenerated plants from cv. Ailes was particularly interesting, because the appearance of a particular phenotype could be related to the in vitro activation of a transposable element.Key words: Secale cereale, regeneration, somaclonal variation, albino plants, transposable elements.

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Tubulin Subunits Exist in an Activated Conformational State Generated and Maintained by Protein Cofactors

The Journal of Cell Biology ◽

10.1083/jcb.138.4.821 ◽

1997 ◽

Vol 138 (4) ◽

pp. 821-832 ◽

Cited By ~ 128

Author(s):

Guoling Tian ◽

Sally A. Lewis ◽

Becket Feierbach ◽

Timothy Stearns ◽

Heidi Rommelaere ◽

...

Keyword(s):

Complex Formation ◽

Genetic Analysis ◽

Conformational State ◽

The Other ◽

Β Subunit ◽

Α Subunit ◽

Folding Intermediates ◽

Integrated Study ◽

Β Tubulin

The production of native α/β tubulin heterodimer in vitro depends on the action of cytosolic chaperonin and several protein cofactors. We previously showed that four such cofactors (termed A, C, D, and E) together with native tubulin act on β-tubulin folding intermediates generated by the chaperonin to produce polymerizable tubulin heterodimers. However, this set of cofactors generates native heterodimers only very inefficiently from α-tubulin folding intermediates produced by the same chaperonin. Here we describe the isolation, characterization, and genetic analysis of a novel tubulin folding cofactor (cofactor B) that greatly enhances the efficiency of α-tubulin folding in vitro. This enabled an integrated study of α- and β-tubulin folding: we find that the pathways leading to the formation of native α- and β-tubulin converge in that the folding of the α subunit requires the participation of cofactor complexes containing the β subunit and vice versa. We also show that sequestration of native α-or β-tubulins by complex formation with cofactors results in the destabilization and decay of the remaining free subunit. These data demonstrate that tubulin folding cofactors function by placing and/or maintaining α-and β-tubulin polypeptides in an activated conformational state required for the formation of native α/β heterodimers, and imply that each subunit provides information necessary for the proper folding of the other.

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Cytogenetic variation in rye regenerated plants and their progeny

Genome ◽

10.1139/g92-063 ◽

1992 ◽

Vol 35 (3) ◽

pp. 428-430 ◽

Cited By ~ 12

Author(s):

R. Linacero ◽

A. M. Vazquez

Keyword(s):

Chromosome Number ◽

Somaclonal Variation ◽

Secale Cereale ◽

Immature Embryo ◽

Meiotic Abnormalities ◽

Regenerated Plants

Regenerated plants obtained from immature embryo-derived calluses of four cultivars of rye, as well as their progeny, were cytologically analyzed. Chromosome number modified plants were found among the regenerants. The progeny of apparently normal diploid regenerated plants was tested and in some cases chromosomally abnormal plants appeared. Equally, meiotic abnormalities were observed in some of the regenerated plants and their progenies. The cytological variations observed were inheritable and in some cases both types of abnormalities could be related. The nature of the variations is discussed.Key words: Secale cereale, somaclonal variation, nondiploid plants, meiotic abnormalities.

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GENERAL NONCHEMOTACTIC MUTANTS OF CAULOBACTER CRESCENTUS

Genetics ◽

10.1093/genetics/114.3.717 ◽

1986 ◽

Vol 114 (3) ◽

pp. 717-730

Author(s):

Bert Ely ◽

Connie J Gerardot ◽

Donna L Fleming ◽

Suely L Gomes ◽

Peter Frederikse ◽

...

Keyword(s):

Genetic Analysis ◽

Gene Cluster ◽

Caulobacter Crescentus ◽

Chemotactic Response ◽

The Other ◽

In Vitro Experiments ◽

Methyltransferase Activity ◽

Chemotaxis Proteins

ABSTRACT We have examined 35 mutants that have defects in general chemotaxis. Genetic analysis of these mutants resulted in the identification of at least eight che genes located at six different positions on the Caulobacter crescentus chromosome. The cheR, cheB and cheT genes appeared to be located in a three-gene cluster. Mutations in these three genes resulted in the inability of the flagellum to reverse the direction of rotation. Defects in the cheR gene resulted in a loss of the ability to methylate the methyl-accepting chemotaxis proteins. In vitro experiments showed that the lack of in vivo methylation in cheR mutants was due to the absence of methyltransferase activity. Defects in the cheB gene resulted in greatly reduced chemotaxis-associated methylation in vivo and a loss of methylesterase activity in vitro. The specific defects responsible for the lack of a chemotactic response have not been determined for the other identified che genes.

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Mitochondrial DNA amplification in albino plants of rye (Secale cereale L.) regenerated in vitro

Plant Science ◽

10.1016/j.plantsci.2009.02.016 ◽

2009 ◽

Vol 176 (6) ◽

pp. 722-728 ◽

Cited By ~ 3

Author(s):

Isabel Ballesteros ◽

Rosario Linacero ◽

Ana M. Vázquez

Keyword(s):

Mitochondrial Dna ◽

Secale Cereale ◽

Dna Amplification ◽

Albino Plants ◽

Secale Cereale L

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Enhancement of ADP-induced Platelet Aggregation by Adrenaline in Vivo and Its Prevention

Thrombosis and Haemostasis ◽

10.1055/s-0038-1647788 ◽

1973 ◽

Vol 29 (02) ◽

pp. 490-498 ◽

Cited By ~ 6

Author(s):

Hiroh Yamazaki ◽

Itsuro Kobayashi ◽

Tadahiro Sano ◽

Takio Shimamoto

Keyword(s):

Platelet Count ◽

Platelet Aggregation ◽

Platelet Rich Plasma ◽

The Other ◽

Endothelial Surface ◽

Important Interaction ◽

Blood Coagulability ◽

The Difference

SummaryThe authors previously reported a transient decrease in adhesive platelet count and an enhancement of blood coagulability after administration of a small amount of adrenaline (0.1-1 µg per Kg, i. v.) in man and rabbit. In such circumstances, the sensitivity of platelets to aggregation induced by ADP was studied by an optical density method. Five minutes after i. v. injection of 1 µg per Kg of adrenaline in 10 rabbits, intensity of platelet aggregation increased to 115.1 ± 4.9% (mean ± S. E.) by 10∼5 molar, 121.8 ± 7.8% by 3 × 10-6 molar and 129.4 ± 12.8% of the value before the injection by 10”6 molar ADP. The difference was statistically significant (P<0.01-0.05). The above change was not observed in each group of rabbits injected with saline, 1 µg per Kg of 1-noradrenaline or 0.1 and 10 µg per Kg of adrenaline. Also, it was prevented by oral administration of 10 mg per Kg of phenoxybenzamine or propranolol or aspirin or pyridinolcarbamate 3 hours before the challenge. On the other hand, the enhancement of ADP-induced platelet aggregation was not observed in vitro, when 10-5 or 3 × 10-6 molar and 129.4 ± 12.8% of the value before 10∼6 molar ADP was added to citrated platelet rich plasma (CPRP) of rabbit after incubation at 37°C for 30 second with 0.01, 0.1, 1, 10 or 100 µg per ml of adrenaline or noradrenaline. These results suggest an important interaction between endothelial surface and platelets in connection with the enhancement of ADP-induced platelet aggregation by adrenaline in vivo.

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ALDOSTERONE STIMULATION IN VITRO

Acta Endocrinologica ◽

10.1530/acta.0.0500301 ◽

1965 ◽

Vol 50 (2) ◽

pp. 301-309 ◽

Cited By ~ 13

Author(s):

Jürg Müller

Keyword(s):

Ammonium Chloride ◽

Human Urine ◽

Incubation Medium ◽

The Other ◽

Ammonium Ions ◽

Response Curves ◽

Urine Extract ◽

Similar Dose ◽

Aldosterone Production

ABSTRACT An extract of human urine, which was previously shown to stimulate aldosterone production by rat adrenal sections, was further purified. Evidence was obtained that its aldosterone-stimulating effect was due to the presence of ammonium ions. Addition of ammonium chloride and of urine extract to the incubation medium caused identical increases in aldosterone production in vitro. In addition to ammonium ions, rubidium and caesium ions also stimulated aldosterone production up to 250% that of control values without a significant effect on corticosterone production. Similar dose-response curves were obtained when increasing concentrations of potassium, ammonium, rubidium and caesium ions were tested. Aldosterone production was maximal at concentrations of 7 mval/1 and was significantly lower at higher concentrations. When ammonium chloride and ACTH were simultaneously added to the incubation medium, the production of aldosterone and of corticosterone was lower than with ACTH alone. On the other hand, the stimulating activity on aldosterone and corticosterone production by »TPN« (NADP) and glucose-6-phosphate was enhanced by the simultaneous addition of ammonium chloride.

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EFFECT OF ACTINOMYCIN D ON TSH-INDUCED STIMULATION OF THYROIDAL PROTEIN SYNTHESIS IN THE RAT

Acta Endocrinologica ◽

10.1530/acta.0.0770064 ◽

1974 ◽

Vol 77 (1) ◽

pp. 64-70 ◽

Cited By ~ 9

Author(s):

Gustav Wägar

Keyword(s):

Protein Synthesis ◽

Actinomycin D ◽

The Other ◽

Leucine Incorporation ◽

Short Term ◽

Other Hand ◽

Thyroid Glands ◽

Translational Level ◽

Stimulation Of

ABSTRACT Whether the short-term regulation of thyroidal protein synthesis by TSH occurs at the transcriptional or the translational level was tested by measuring the effect of actinomycin D (act D) on the TSH-induced stimulation of L-14C-leucine incorporation into the thyroidal proteins of rats. TSH was injected 6 h before the rats were killed. The thyroid glands were then removed and incubated in vitro in the presence of L-14C-leucine for 2 h. The pronounced stimulation of leucine incorporation in the TSH-treated animals was depressed as compared with controls but still significant even when the animals had been pre-treated with 100 μg act D 24 and 7 h before sacrifice. On the other hand, act D strongly decreased incorporation of 3H-uridine into RNA. Short-term regulation of thyroidal protein synthesis by TSH appears to be partly but not wholly dependent on neosynthesis of RNA. Hence regulation may partly occur at the translation level of protein synthesis.

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