CYTOGENETIC EFFECTS OF 2,4-D AND AMITROLE IN RELATION TO NUCLEAR VOLUME AND DNA CONTENT IN SOME HIGHER PLANTS

1972 ◽  
Vol 14 (4) ◽  
pp. 773-783 ◽  
Author(s):  
T. Mohandas ◽  
W. F. Grant
Keyword(s):  
Hordeum Vulgare ◽  
Nuclear Dna ◽  
Higher Plants ◽  
Positive Control ◽  
Root Tip ◽  
Interphase Chromosome ◽  
Dna Values ◽  
Cytological Abnormalities ◽  
Centaurea Jacea ◽  
Chrysanthemum Leucanthemum

The cytological effects of 2,4-D and amitrole were studied for 12 species (Tradescantia clone 02, Allium cepa, Vicia faba, Triticum aestivum, T. dicoccum, Hordeum vulgare, Secale cereale, Centaurea jacea, Cirsium vulgare, Chrysanthemum leucanthemum, Plantago major and Erigeron canadensis). Ethyl methane sulfonate (EMS) was used as a positive control. The cytological abnormalities induced in root-tip cells by both 2,4-D and amitrole included chromosome bridges, fragments, lagging chromosomes, and chromatin bodies; 2,4-D also induced chromosome contraction, and C-mitoses. Studies following seed treatments of Hordeum vulgare on M2 seedlings showed that 2,4-D and EMS induced albina mutants. Interphase nuclear volumes of the various species were measured from root-tip meristems. Nuclear DNA values were determined cytophotometrically for seven species. The relative DNA values were found to be positively correlated with nuclear volumes. The lack of any clear relationship between the number of cytological abnormalities induced by the chemicals and the nuclear and interphase chromosome volumes of the plants probably reflects a lack of synchrony of the treated cell population.

The time and duration of female meiosis in wheat, rye and barley

1973 ◽  
Vol 183 (1072) ◽  
pp. 301-319 ◽  
Keyword(s):  
Hordeum Vulgare ◽  
Nuclear Dna ◽  
Higher Plants ◽  
Embryo Sac ◽  
Nuclear Dna Content ◽  
Male Meiosis ◽  
Female Development ◽  
Female Meiosis ◽  
Male And Female ◽  
Mother Cells

Few recent investigations have been made of female meiosis in cereals, and almost nothing is known about the duration of female meiosis in higher plants. Consequently, the time and duration of female meiosis in Triticum aestivum , Hordeum vulgare and Secale cereale have been studied. The appearance of the embryo sac mother cell (e. m. c.) and of the meiotic nuclei during female meiosis in Hordeum vulgare is described and illustrated. In the species studied, each floret contains only one ovary with a single e. m. c., and meiosis is almost synchronous in the pollen mother cells from all three anthers. Conse­quently, it is possible to make precise comparisons between the stages of male and female development within individual florets. Data from these comparisons, together with know­ledge previously determined of the duration of male meiosis in these species, allowed the estimation of the time and duration of female meiosis fairly accurately for T. aestivum and H. vulgare and approximately for S. cereale . The results showed that for H. vulgar and T. aestivum grown at 20°C, the duration of female meiosis was very similar to the duration of male meiosis. Furthermore, on average male and female meiosis occurred almost synchronously. In S. cereale however, male meiosis preceeded female meiosis by about 15 h. Growing T. aestivum under environmental stress induced asynchrony between male and female development at meiosis. Synchrony was not re-established after a long period under normal conditions. Nuclear DNA content and ploidy level are known to be important factors determining or affecting the duration of male meiosis. These factors appear to play an important role in controlling the duration of female meiosis also.

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.

A correlation of nuclear DNA content and thin-layer chromatographic patterns in resolving genome relationships in Avena

1972 ◽  
Vol 50 (7) ◽  
pp. 1529-1545 ◽  
Author(s):  
Koji Iiyama ◽  
William F. Grant
Keyword(s):  
Thin Layer ◽  
Dna Content ◽  
Nuclear Dna ◽  
Nuclear Dna Content ◽  
Chromosomal Polymorphism ◽  
Root Tip ◽  
Coumaric Acid ◽  
Leaf Extracts ◽  
B Genome ◽  
Nuclear Deoxyribonucleic Acid

Relative amounts of nuclear deoxyribonucleic acid (DNA) from telophase root tip nuclei and thin-layer chromatographic patterns of alcohol-soluble compounds from dry leaves were determined for seven diploids: Avena clauda, A. pilosa, A. ventricosa, A. strigosa, A. hirtula, A. wiestii, A. longiglumis; four tetraploids: A. barbata, A. magna, A. abyssinica, A. vaviloviana; and four hexaploids: A. sterilis, A. fatua, A. byzantina, and A. sativa, in order to elucidate species relationships. Variation in nuclear DNA content was correlated with differences in genomic constitution; a few exceptions are considered to reflect chromosomal polymorphism. The average DNA value of the hexaploid species approximated the sum of the DNA value for A. magna and the theoretical value of the B genome. Chromatographic patterns showed distinct variations between species but little correlation between number of compounds and DNA content. Chromatographic patterns of hexaploids showed close similarity with those of diploids and tetraploids, except species with modified C genomes (A. clauda, A. pilosa, A. ventricosa) and A. longiglumis. It is considered that A. clauda, A. pilosa, A. ventricosa, and A. longiglumis did not participate in the evolution of polyploid taxa. From their chromatographic profiles, A. wiestii, A. abyssinica, A. vaviloviana, and A. byzantina are very closely related. Both A. magna and the AABB tetraploid species appear to share two genomes in common with the hexaploids. Hence, the genomic constitutions AADD and AABBDD have been proposed for A. magna and the hexaploids, respectively. Six compounds from ethanol leaf extracts of A. sativa were identified as three apigenins, luteolin, ferulic acid, and p-coumaric acid.

scholarly journals Cytokinesis in tobacco BY-2 and root tip cells: a new model of cell plate formation in higher plants.

1995 ◽  
Vol 130 (6) ◽  
pp. 1345-1357 ◽  
Author(s):  
A L Samuels ◽  
T H Giddings ◽  
L A Staehelin
Keyword(s):  
Higher Plants ◽  
Membrane Surface ◽  
Cell Plate ◽  
Root Tip ◽  
Cellulose Synthesis ◽  
Parent Cell ◽  
Cell Periphery ◽  
New Model ◽  
Cell Plate Formation ◽  
Plate Formation

Cell plate formation in tobacco root tips and synchronized dividing suspension cultured tobacco BY-2 cells was examined using cryofixation and immunocytochemical methods. Due to the much improved preservation of the cells, many new structural intermediates have been resolved, which has led to a new model of cell plate formation in higher plants. Our electron micrographs demonstrate that cell plate formation consists of the following stages: (1) the arrival of Golgi-derived vesicles in the equatorial plane, (2) the formation of thin (20 +/- 6 nm) tubes that grow out of individual vesicles and fuse with others giving rise to a continuous, interwoven, tubulo-vesicular network, (3) the consolidation of the tubulo-vesicular network into an interwoven smooth tubular network rich in callose and then into a fenestrated plate-like structure, (4) the formation of hundreds of finger-like projections at the margins of the cell plate that fuse with the parent cell membrane, and (5) cell plate maturation that includes closing of the plate fenestrae and cellulose synthesis. Although this is a temporal chain of events, a developing cell plate may be simultaneously involved in all of these stages because cell plate formation starts in the cell center and then progresses centrifugally towards the cell periphery. The "leading edge" of the expanding cell plate is associated with the phragmoplast microtubule domain that becomes concentrically displaced during this process. Thus, cell plate formation can be summarized into two phases: first the formation of a membrane network in association with the phragmoplast microtubule domain; second, cell wall assembly within this network after displacement of the microtubules. The phragmoplast microtubules end in a filamentous matrix that encompasses the delicate tubulo-vesicular networks but not the tubular networks and fenestrated plates. Clathrin-coated buds/vesicles and multivesicular bodies are also typical features of the network stages of cell plate formation, suggesting that excess membrane material may be recycled in a selective manner. Immunolabeling data indicate that callose is the predominant lumenal component of forming cell plates and that it forms a coat-like structure on the membrane surface. We postulate that callose both helps to mechanically stabilize the early delicate membrane networks of forming cell plates, and to create a spreading force that widens the tubules and converts them into plate-like structures. Cellulose is first detected in the late smooth tubular network stage and its appearance seems to coincide with the flattening and stiffening of the cell plate.

The genome sizes of Hordeum species show considerable variation

Genome ◽  
1996 ◽  
Vol 39 (4) ◽  
pp. 730-735 ◽  
Author(s):  
Juha Kankanpää ◽  
Alan H. Schulman ◽  
Leena Mannonen
Keyword(s):  
Flow Cytometry ◽  
Hordeum Vulgare ◽  
Genome Size ◽  
Nuclear Dna ◽  
Size Variation ◽  
Nuclear Dna Content ◽  
Meiotic Pairing ◽  
Genome Size Variation ◽  
Dapi Staining ◽  
Hordeum Vulgare Ssp

Hordeum, distributed worldwide in temperate zones, is the second largest genus in the tribe Triticeae and includes diploid, tetraploid, and hexaploid species. We determined, by DAPI staining and flow cytometry, the nuclear DNA content for 35 accessions of the genus Hordeum, from a total of 19 species, including specimens of 2 cultivars and 2 landraces of Hordeum vulgare ssp. vulgare as well as samples of 12 Hordeum vulgare ssp. spontaneum populations. Genome sizes ranged from 5.69 to 9.41 pg for the G1 nuclei of the diploids, and from 13.13 to 18.36 pg for those of the tetraploids. This constitutes a 1.7-fold variation for the diploids, contrasting with a 4% variation previously reported. For H. vulgare ssp. vulgare (barley), the accessions examined differed by 18%. These variations in genome size cannot be correlated with meiotic pairing groups (I, H, X, Y) or with proposed phylogenetic relationships within the genus. Genome size variation between barley accessions cannot be related to status as cultivated or wild, or to climatic or geological gradients. We suggest these data may indicate rapid but sporadic changes in genome size within the genus. Key words : barley, Hordeum, Triticeae, genome size, flow cytometry.

scholarly journals NUCLEAR DNA AND CYTOPLASMIC DNA FROM TISSUES OF HIGHER PLANTS

1965 ◽  
Vol 27 (3) ◽  
pp. 451-457 ◽  
Author(s):  
Yasuo Hotta ◽  
Alix Bassel ◽  
Herbert Stern
Keyword(s):  
Inorganic Phosphate ◽  
Nuclear Dna ◽  
Higher Plants ◽  
Soluble Fraction ◽  
Buoyant Density ◽  
Wheat Roots ◽  
Cytoplasmic Dna ◽  
Sucrose Medium

Young wheat roots were labeled with 32P-inorganic phosphate. Following the labeling period, roots were homogenized in a sucrose medium and fractionated into nuclei, cytoplasmic particles (including proplastids and mitochondria), and a soluble fraction containing most of the microsomes. DNA prepared from the particles had a higher buoyant density than that from the nuclei and showed a marked loss in total label if the roots were exposed to non-radioactive medium for 48 hours prior to fractionation of the cells.

High-resolution flow cytometry of nuclear DNA in higher plants

PROTOPLASMA ◽  
1991 ◽  
Vol 165 (1-3) ◽  
pp. 212-215 ◽  
Author(s):  
I. Ulrich ◽  
W. Ulrich
Keyword(s):  
Flow Cytometry ◽  
High Resolution ◽  
Nuclear Dna ◽  
Higher Plants

Performance of isolated microspore-derived doubled haploids of wheat (Triticum aestivum L.)

1997 ◽  
Vol 77 (4) ◽  
pp. 549-554 ◽  
Author(s):  
Tianci Hu ◽  
Ken J. Kasha
Keyword(s):  
In Vitro Selection ◽  
Nuclear Dna ◽  
Chromosome Doubling ◽  
Microspore Culture ◽  
Doubled Haploids ◽  
Spontaneous Mutation ◽  
Nuclear Dna Content ◽  
Root Tip ◽  
Ploidy Levels ◽  
Dh Lines

Ploidy level, genetic stability and field performance of isolated microspore-derived wheat plants were evaluated. The ploidy levels of isolated microspore-derived wheat plants from cv. Chris and reciprocal crosses of Chris × Sinton were determined by two methods, namely chromosome counts of root tip cells and flow cytometric measurement of nuclear DNA content from leaves. Both methods gave similar results with the frequencies of spontaneous chromosome doubling and completely fertile plants among microspore-derived H0 plants of wheat being about 80% and 75%, respectively, based on two H0 populations. Only 1.7% were aneuploid and 16% were haploid. Spontaneous mutation frequencies were low with 1 of 124 Chris DH plants having a recessive mutant for lemma awns while three were grass-like plants in the H0 generation. The field-measured traits of microspore-derived DH lines were similar to the check by the third generation. Ninety-two percent and 70% of Chris DH lines had 1000-kernel weights and yields similar to the check, respectively. These results indicate that microspore-derived DH lines should have good potential for applications in plant breeding, in vitro selection, plant transformation and genetic studies. Key words: Wheat, microspore, culture, haploidy, performance, stability

Nuclear DNA amount in pure species and hybrid willows (Salix): a flow cytometric investigation

1998 ◽  
Vol 76 (1) ◽  
pp. 157-165 ◽  
Author(s):  
Jérôme Thibault
Keyword(s):  
Flow Cytometry ◽  
Ploidy Level ◽  
Dna Content ◽  
Nuclear Dna ◽  
Nuclear Dna Content ◽  
Natural Hybridization ◽  
Ploidy Levels ◽  
Key Words Flow Cytometry ◽  
Dna Values ◽  
Dna Amounts

Flow cytometry (FCM) has been used to estimate the nuclear DNA content of 11 Salix species and 5 hybrids. One hundred and sixty nine individuals were studied including 159 individuals from a sequence of 32 communities along a stretch of river in France and 10 individuals from French and English collections for comparison. Isolated nuclei were stained with propidium iodide. FCM was a significantly more practical and rapid technique than that of establishing the karyotype to survey many samples of Salix for variation in ploidy. The 2C DNA amounts for diploid species ranged from 0.76 to 0.98 pg, and tetraploid values ranged from 1.62 to 1.80 pg. The DNA values were consistent with the known ploidy levels. With the exception of a doubtful Salix xquercifolia, ploidy levels and DNA amounts of hybrids were intermediate compared with those of their parents. Intraspecific variation of nuclear DNA values including instrumental variation was low (i.e., 6-11% at the same ploidy level). FCM appeared to be an accurate tool for determination of Salix triploid hybrids. However, it remains limited concerning hybrids from crosses between species of the same ploidy level. Results suggest that natural hybridization might not be frequent in the communities studied, although they have been subject to disturbance. Previous overestimates of hybridization frequency in willows were probably due to misinterpretation of the effects of the environment on Salix spp. morphology; however, the extent and mechanisms of introgression in the genus remain to be further investigated. Key words: flow cytometry, Salix, hybridization, nuclear DNA content, riparian vegetation, disturbance.

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