Spindle sensitivity to colchicine of the Ph1 mutant in common wheat

1984 ◽  
Vol 26 (2) ◽  
pp. 111-118 ◽  
Author(s):  
Carla Ceoloni ◽  
Lydia Avivi ◽  
Moshe Feldman
Keyword(s):  
Common Wheat ◽  
Root Tip ◽  
Control Line ◽  
Wild Type ◽  
Chromosomal Distribution ◽  
Chromosome 5B ◽  
Ph1 Locus ◽  
Ph1 Gene ◽  
Tip Cells ◽  
Different Doses

Mitotic spindle sensitivity to colchicine of a common wheat line carrying a mutation at the Ph1 locus which increases homoeologous pairing at meiosis, was studied in treated root-tip cells and compared with that of wild type (Ph1/Ph1) and plants deficient for chromosome 5B. Spindle sensitivity was determined by the percentage of fully affected cells of the overall metaphase cell population. The high-pairing mutant (ph1b/ph1b), which is assumed to be a deficiency for the Ph1 locus on the long arm of chromosome 5B, was found to be significantly more sensitive to colchicine than the corresponding control line, i.e., plants carrying the wild-type allele, Ph1. The sensitivity of the mutant was similar to that of plants deficient for chromosome 5B. It thus becomes highly probable that spindle sensitivity to colchicine, previously found in plants carrying different doses of chromosomal arm 5BL, is indeed determined by the Ph1 gene. This gene presumably exerts its effect on the spindle via modification of some microtubular components. Thus, microtubules are suggested to be a possible target structure for this gene, which is known to affect chromosomal distribution and degree of homologous and homoeologous association in somatic and premeiotic cells, as well as the pattern of meiotic pairing.Key words: spindle, Triticum, microtubules, colchicine.

Spindle sensitivity to isopropyl-N-phenyl-carbamate and griseofulvin of common wheat plants carrying different doses of the Ph1 gene

1984 ◽  
Vol 26 (2) ◽  
pp. 119-127 ◽  
Author(s):  
Giampiero Gualandi ◽  
Carla Ceoloni ◽  
Moshe Feldman ◽  
Lydia Avivi
Keyword(s):  
Common Wheat ◽  
Chinese Spring ◽  
The Other ◽  
Microtubule Organization ◽  
Chromosome 5B ◽  
Ph1 Gene ◽  
Complete Disruption ◽  
Spindle Microtubules ◽  
Different Doses ◽  
Microtubule Structure

Lines of common wheat cv. 'Chinese Spring' carrying different doses of the Ph1 gene, located on the long arm of chromosome 5B were treated with the antimitotic agents griseofulvin and isopropyl-N-phenyl-carbamate (IPC). Treatments with low griseofulvin concentrations and IPC resulted mainly in the production of a high percentage of cells exhibiting spindle disorganization at metaphase and multipolar cells at anaphase–telophase. These treatments did not differentially affect the tested genotypes. On the other hand, higher griseofulvin concentrations induced the appearance of frequent C-metaphases and C-anaphases because of complete disruption of the spindle microtubules; in such cases, more pronounced sensitivity was observed in a line lacking the Ph1 gene than in lines disomic and tetrasomic for chromosome 5B. From this evidence it can be concluded that subcellular structures regulating microtubule organization and orientation, which are apparently the target of IPC and low griseofulvin concentrations, are not related to the action of the Ph1 gene. Rather, tubulin–microtubules equilibrium, which is affected by colchicine and high griseofulvin concentrations, is influenced by the action of this gene. Thus, the Ph1 gene product may correspond to a tubulin or a microtubule-associated protein which in turn stabilizes microtubule structure. In either case, the equilibrium tubulin–microtubules would be shifted towards microtubules in plants containing two doses of Ph1 and even more in plants containing an extra dose of this gene.Key words: spindle, Triticum, microtubules, antitubulins, griseofulvin.

Effect of Ph2 mutants promoting homoeologous pairing on spindle sensitivity to colchicine in common wheat

Genome ◽  
1987 ◽  
Vol 29 (4) ◽  
pp. 658-663
Author(s):  
Carla Ceoloni ◽  
Moshe Feldman
Keyword(s):  
Common Wheat ◽  
Suppressor Gene ◽  
Intergeneric Hybrids ◽  
Differential Sensitivity ◽  
Root Tip ◽  
Lower Sensitivity ◽  
Homoeologous Pairing ◽  
Wild Type ◽  
Cellular Target ◽  
Chromosome Arm

Two lines of common wheat cv. Chinese Spring carrying mutant alleles for the Ph2 homoeologous pairing-suppressor gene on chromosome arm 3DS promoting homoeologous pairing in wheat interspecific and intergeneric hybrids have been tested for their mitotic sensitivity to colchicine. Both the ph2a mutation, which corresponds to a fairly long deletion of 3DS, and ph2b, which is either an intragenic change or a very small deletion, as well as the ph2a/ph2b heteroallelic combination and the deficiency for the entire 3DS arm (ditelo 3DL), conditioned a significantly lower sensitivity to colchicine than that determined by the wild-type allele Ph2 (euploid and ditelo 3DS). Observation of both metaphase and anaphse root-tip cell populations, treated with various colchicine concentrations, provided similar results. The degree of spindle disruption in 2 × 10−4 M colchicine, as measured by the percentage of fully affected metaphases (C type), was significantly reduced in ph2 and Ph2− genotypes and, consequently, a larger proportion of cells could proceed toward anaphase and also had a regular segregation pattern at this stage. The differential sensitivity of ph2 genotypes to colchicine is in the opposite direction to that previously found for ph1 genotypes, lacking the homoeologous pairing suppressor on chromosome arm 5BL. The ph2 mutation, while promoting homoeologous pairing as ph1 does, decreases spindle sensitivity to colchicine with respect to the wild-type (ph2) allele rather than increasing it, as ph1 does. The observed alteration of spindle sensitivity to colchicine that mutants for structurally unrelated but functionally related genes (Ph1 and Ph2) condition is interpreted as a highly probable coincidence in their cellular target. It is assumed therefore that these loci affect the equilibrium between tubulin and microtubules. Through this effect they presumably determine chromosome positioning in somatic and premeiotic stages, leading to different pairing patterns at meiosis. Key words: Triticum aestivum, tubulin, pairing suppressors, somatic association.

scholarly journals THE MECHANISM OF SOMATIC ASSOCIATION IN COMMON WHEAT, TRITICUM AESTIVUM L. IV. FURTHER EVIDENCE FOR MODIFICATION OF SPINDLE TUBULIN THROUGH THE SOMATIC-ASSOCIATION GENES AS MEASURED BY VINBLASTINE BINDING

Genetics ◽  
1973 ◽  
Vol 73 (3) ◽  
pp. 379-385
Author(s):  
Lydia Avivi ◽  
Moshe Feldman
Keyword(s):  
Triticum Aestivum ◽  
Genetic Control ◽  
Common Wheat ◽  
Triticum Aestivum L ◽  
Suppressor Gene ◽  
Single Site ◽  
Root Tip ◽  
Binding Ability ◽  
Tip Cells ◽  
Root Tip Cells

ABSTRACT Treatment with the antitubulin vinblastine was found to disrupt the spindle system in dividing root-tip cells of common wheat, Triticum aestivum L. Genotypes lacking the somatic association suppressor gene on 5BL, or containing the somatic-association promoter on 5BS, were found to be more sensitive to the treatment. In genetic lines carrying the somatic association suppressor, sensitivity to vinblastine was lower and there was a direct correlation between dosage of the suppressor gene (0, 2, and 4) and the decrease in spindle disruption on exposure to various concentrations of vinblastine. It is concluded that the somatic association genes affect binding ability of spindle tubulin to vinblastine. Since the same genes affect binding of colchicine to tubulin and since the two alkaloids attach to different sites it is assumed that the somatic association suppressor gene has a broad effect on the tubulin molecules which is not confined to a single site. The relevance of genetic control of antitubulin binding to somatic association is discussed.

The effect of the Ph1 gene in diploid rye, Secale cereale L.

Genome ◽  
1991 ◽  
Vol 34 (6) ◽  
pp. 913-917 ◽  
Author(s):  
R. Schlegel ◽  
A. Boerner ◽  
V. Thiele ◽  
G. Melz
Keyword(s):  
Chromosome Pairing ◽  
Chiasma Frequency ◽  
Addition Line ◽  
Homologous Pairing ◽  
Chromosome 5B ◽  
Secale Cereale L ◽  
Ph1 Locus ◽  
Ph1 Gene ◽  
Bivalent Formation ◽  
Octoploid Triticale

Experimental results demonstrated clearly that the dominant Ph1 allele of chromosome 5B of wheat affects the homologous pairing of rye chromosomes. A rye-wheat monotelosomic 5BL addition line was produced and used for meiotic studies. Compared with 14-chromosome control plants, the 5BL addition to rye causes an increase in univalents and rod bivalent formation, i.e., a significant reduction of chiasma frequency (11.21 chiasmata per pollen mother cell). The 5BL telosome itself does not associate with any of the rye chromosomes. Thus, the double dosage of 5BL, present in hexaploid or octoploid triticale, could be one of the main causes of pairing failure of the rye genome.Key words: chromosome pairing, Ph1 locus, wheat, rye, rye-wheat addition.

Localization of Adenosine Triphosphatase Activity in the Phleom of Nicotiana Tabacum

1972 ◽  
Vol 30 ◽  
pp. 230-231
Author(s):  
James Cronshaw ◽  
Jamison E. Gilder
Keyword(s):  
Plasma Membrane ◽  
Atpase Activity ◽  
Adenosine Triphosphatase ◽  
Higher Plants ◽  
High Surface ◽  
Root Tip ◽  
Animal Cells ◽  
Physiological Processes ◽  
Tip Cells ◽  
Atpase Localization

Adenosine triphosphatase (ATPase) activity has been shown to be associated with numerous physiological processes in both plants and animal cells. Biochemical studies have shown that in higher plants ATPase activity is high in cell wall preparations and is associated with the plasma membrane, nuclei, mitochondria, chloroplasts and lysosomes. However, there have been only a few ATPase localization studies of higher plants at the electron microscope level. Poux (1967) demonstrated ATPase activity associated with most cellular organelles in the protoderm cells of Cucumis roots. Hall (1971) has demonstrated ATPase activity in root tip cells of Zea mays. There was high surface activity largely associated with the plasma membrane and plasmodesmata. ATPase activity was also demonstrated in mitochondria, dictyosomes, endoplasmic reticulum and plastids.

Cytotoxic Effect of Sewage Effluent on Root Tip Cells of Allium cepa L.

2016 ◽  
Vol 2 (1) ◽  
pp. 18 ◽  
Author(s):  
M. T. Teena ◽  
K. R. Soumya ◽  
K. S. Sudha
Keyword(s):  
Allium Cepa ◽  
Cytotoxic Effect ◽  
Root Tip ◽  
Sewage Effluent ◽  
Tip Cells ◽  
Root Tip Cells

Effect of the Pairing Gene Ph1 and Premeiotic Colchicine Treatment on Intra- and Interchromosome Pairing of Isochromosomes in Common Wheat

Genetics ◽  
1998 ◽  
Vol 150 (3) ◽  
pp. 1199-1208 ◽  
Author(s):  
Juan M Vega ◽  
Moshe Feldman
Keyword(s):  
Common Wheat ◽  
Homologous Chromosome ◽  
Colchicine Treatment ◽  
Crossing Over ◽  
Meiotic Pairing ◽  
Factors Affecting ◽  
Homologous Chromosomes ◽  
Polyploid Wheat ◽  
Main Gene ◽  
Ph1 Gene

Abstract The analysis of the pattern of isochromosome pairing allows one to distinguish factors affecting presynaptic alignment of homologous chromosomes from those affecting synapsis and crossing-over. Because the two homologous arms in an isochromosome are invariably associated by a common centromere, the suppression of pairing between these arms (intrachromosome pairing) would indicate that synaptic or postsynaptic events were impaired. In contrast, the suppression of pairing between an isochromosome and its homologous chromosome (interchromosome pairing), without affecting intrachromosome pairing, would suggest that homologous presynaptic alignment was impaired. We used such an isochromosome system to determine which of the processes associated with chromosome pairing was affected by the Ph1 gene of common wheat—the main gene that restricts pairing to homologues. Ph1 reduced the frequency of interchromosome pairing without affecting intrachromosome pairing. In contrast, intrachromosome pairing was strongly reduced in the absence of the synaptic gene Syn-B1. Premeiotic colchicine treatment, which drastically decreased pairing of conventional chromosomes, reduced interchromosome but not intrachromosome pairing. The results support the hypothesis that premeiotic alignment is a necessary stage for the regularity of meiotic pairing and that Ph1 relaxes this alignment. We suggest that Ph1 acts on premeiotic alignment of homologues and homeologues as a means of ensuring diploid-like meiotic behavior in polyploid wheat.

scholarly journals Threshold dose of cytogenetic toxicity of lindane, malathion and metacid in allium cepa root-tip cells.

CYTOLOGIA ◽  
1989 ◽  
Vol 54 (3) ◽  
pp. 547-552 ◽  
Author(s):  
Dinesh Kumar ◽  
S. P. Sinha
Keyword(s):  
Allium Cepa ◽  
Threshold Dose ◽  
Root Tip ◽  
Tip Cells ◽  
Root Tip Cells

1,2,4-Trichlorobenzene Induction of Chromosomal Aberrations and Cell Division of Root-Tip Cells in Vicia faba Seedlings

2003 ◽  
Vol 71 (4) ◽  
pp. 689-697 ◽  
Author(s):  
W. Liu ◽  
Q.-X. Zhou ◽  
P.-J. Li ◽  
T.-H. Sun ◽  
Y.-S. Yang ◽  
...  
Keyword(s):  
Cell Division ◽  
Vicia Faba ◽  
Chromosomal Aberrations ◽  
Root Tip ◽  
Tip Cells ◽  
Root Tip Cells

Sunlight decreased genotoxicity of azadirachtin on root tip cells of Allium cepa and Eucrosia bicolor

2010 ◽  
Vol 73 (5) ◽  
pp. 949-954 ◽  
Author(s):  
W. Kwankua ◽  
S. Sengsai ◽  
C. Kuleung ◽  
N. Euawong
Keyword(s):  
Allium Cepa ◽  
Root Tip ◽  
Tip Cells ◽  
Root Tip Cells
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