scholarly journals THE CYTOCHEMICAL LOCALIZATION OF ASCORBIC ACID IN ROOT TIP CELLS

1956 ◽  
Vol 2 (1) ◽  
pp. 87-92 ◽  
Author(s):  
William A. Jensen ◽  
Leroy G. Kavaljian
Keyword(s):  
Ascorbic Acid ◽  
Cell Surface ◽  
Silver Nitrate ◽  
Ribonucleic Acid ◽  
Root Tip ◽  
Root Tips ◽  
Cytochemical Localization ◽  
Meristematic Cells ◽  
Tip Cells ◽  
Root Tip Cells

The intracellular distribution of ascorbic acid was studied in frozen-dried root tips of Allium cepa and Vicia faba by the silver nitrate procedure. The sites of the ascorbic acid as indicated by the deposited silver appear as spherical (0.2 to 0.6 µ in diameter) cytoplasmic particles. The site appears to have small amounts of lipides and to be rich in ribonucleic acid. These particles are concluded to be submicroscopic in size and associated, in the elongating cell, with the cell surface. In the meristematic cells they appear fewer in number and are distributed throughout the cytoplasm.

scholarly journals Cytogenetic impact of sodium chloride stress on root cells of Vigna radiata L. seedlings

2020 ◽  
Vol 45 (2) ◽  
Author(s):  
Jabeen Farheen ◽  
Simeen Mansoor
Keyword(s):  
Mitotic Division ◽  
Root Tip ◽  
Ecological Problem ◽  
Root Tips ◽  
Root Cells ◽  
Nacl Concentration ◽  
Seedling Roots ◽  
Metaphase Stage ◽  
Tip Cells ◽  
Root Tip Cells

AbstractObjectivesThe high salinization stress to seedling is the substantial ecological problem in the ongoing era. It negatively influences the growth that retard mitotic division by enhancing aberrations in nuclear chromatin. In the light of these views, the current work was designed to investigate the response of Vigna seedlings root tip cells to the presence of NaCl ions.Materials and methodsNM-92 and NM19-19 seeds were imbibed separately in distilled water for 24 h and allowed to grow into 0, 50, 150, 250, and 350 mM NaCl solution for 24 h. Excised root tips were stained, and slides were scored at 100× objective for the mitotic index (MI) and chromosomal aberrations.ResultsOur data demonstrated that as NaCl molarity increased, the MI was declined along with various chromatin abnormalities. The 150 mM of NaCl showed more lagging (69%) of chromosomes during anaphase in NM19-19. The highest stickiness at metaphase stage (68%) was found in 250 mM NaCl in variety NM19-19. However, both varieties were differed non-significantly for c-mitosis that was recorded 99% at 350 mM NaCl concentration.ConclusionsThe NaCl ions toxicity induced various cytological anomalies in seedling roots that adversely affect the growth of Vigna seedlings.

A RING CHROMOSOME IN AN F1 HYBRID BETWEEN WHEAT AND AGROPYRON

1959 ◽  
Vol 37 (6) ◽  
pp. 1271-1276 ◽  
Author(s):  
Koichiro Tsunewaki
Keyword(s):  
Ring Chromosome ◽  
Root Tip ◽  
Root Tips ◽  
F1 Hybrid ◽  
Ring Chromosomes ◽  
Differential Elimination ◽  
Tip Cells ◽  
Root Tip Cells ◽  
Mitotic Behavior

A plant having 41 normal rod-shaped chromosomes and a ring chromosome was found among hexaploid.F1 hybrids from a wheat–Agropyron cross. Cytological investigations were carried out to determine the mitotic behavior of this ring chromosome.The investigations revealed that most of the possible products of the breakage–fusion–bridge cycle known to occur in a ring chromosome were present in root tip cells. The fact that a rod-shaped chromosome is not derived from a ring chromosome in the cycle was confirmed, because no metaphase cells examined had 42 or more rod-shaped chromosomes.About 80% of the ring chromosomes were eliminated from the root tips of the seedling after 26 days. The size of the ring chromosome did not appear to influence the rate of elimination. The polyploid nature of the plant may account for the rapid, non-differential elimination of this chromosome.

A DICENTRIC WHEAT CHROMOSOME IN DIVISION

1954 ◽  
Vol 32 (3) ◽  
pp. 491-502 ◽  
Author(s):  
J. W. Morrison
Keyword(s):  
Extra Chromosome ◽  
Wheat Chromosome ◽  
Chiasma Formation ◽  
Root Tip ◽  
Anther Wall ◽  
Somatic Variation ◽  
Root Tips ◽  
The One ◽  
Tip Cells ◽  
Root Tip Cells

A dicentric chromosome was observed in the F2 progeny of an interspecific wheat cross. It is suggested that: the dicentric arose from breakage and fusion of two nonhomologous univalent chromosomes in the preceding meiosis. Because only a few bridges were observed in root tips, anther wall tissue, and in sectioned ovaries, it was concluded that the dicentric persisted in the plant because of parallel separation of the chromatids. Somatic variation was observed in some root tip cells. At meiosis, the dicentric was invariably paired with its two homologues and both centromeres were effective in orientation on the plate. Chains-of-five and even rings-of-five were formed in one spike. In another, the loss of one chromosome arm prevented such associations but several forms of trivalents occurred. In one spike, internal chiasmata were formed in the intercentric region of the chromosome. On the chiasmatype theory of crossing over this should have caused bridges at succeeding stages. Besides the lack of bridges, in some cells at AI there was definite evidence that the dicentric was breaking apart and forming an extra chromosome. To explain this phenomenon it is suggested that the effect of the one centromere was nullified by the other and the full consequences of chromatid breakage and reunion in chiasma formation were not fulfilled.

scholarly journals INCORPORATION OF C14-LABELED MALEIC HYDRAZIDE INTO THE ROOT-TIP CELLS OF ALLIUM CERNUUM, VICIA FABA, AND TRADESCANTIA PALUDOSA

1961 ◽  
Vol 10 (4) ◽  
pp. 567-575 ◽  
Author(s):  
John J. Callaghan ◽  
Paul Grun
Keyword(s):  
Vicia Faba ◽  
Maleic Hydrazide ◽  
Root Tip ◽  
Nucleolar Localization ◽  
Root Tips ◽  
Tip Cells ◽  
Root Tip Cells ◽  
Tradescantia Paludosa

Allium cernuum, Vicia faba, and Tradescantia paludosa were treated by root immersion in maleic hydrazide (1 mM/liter) labeled with C14 (C14-MH) for 1 hour to determine the location within the cell to which MH moves during various periods of time after treatment. Root tips were fixed 24 hours, 48 hours, 72 hours, and 3 weeks after treatment. Autoradiographs of root tips squashed 24 to 72 hours after fixation showed that C14-MH was distributed throughout the nuclei and was particularly concentrated in the nucleoli. The nucleolar localization of the chemical was transitory, fixations made 3 weeks after treatment showing well labeled nuclei many of which completely lacked label in the nucleoli. The chromosomes seen in mitotic divisions of all three species had the same amount of label in euchromatic as heterochromatic areas. Since the chemical was not accumulated preferentially in heterochromatic areas, it seems likely that the reported specificity of MH for the breakage of heterochromatin can not be due to preferential heterochromatic incorporation.

scholarly journals New chromosome numbers in Pilocarpus Vahl (Rutaceae)

2000 ◽  
Vol 14 (1) ◽  
pp. 11-24
Author(s):  
Ladislau A. Skorupa
Keyword(s):  
Chromosome Numbers ◽  
Room Temperature ◽  
Basic Number ◽  
Root Tip ◽  
Root Tips ◽  
Chromosome Counts ◽  
Pre Treatment ◽  
First Time ◽  
Tip Cells ◽  
Root Tip Cells

Chromosome counts for eight species of Pilocarpus Vahl (Rutaceae) a native of Brazil are reported for the first time. Chromosome numbers were determined from mitotic root tip cells of seedlings derived from field collections and grown in the greenhouse. Feulgen staining was used. Initial pre-treatment of root tips was done by using a saturated aqueous solution of alpha-bromonapthalene for two hours at room temperature (20-25ºC). Chromosome numbers of 2n=44 and 2n=88 were determined for the examined taxa. The present results suggest the occurrence of tetraploidy in P. spicatus St.-Hil. and P. carajaensis Skorupa, and a possible basic number x=22 to the genus Pilocarpus.

CHROMOSOME ABERRATIONS PRODUCED BY 5-BROMODEOXYURIDINE WITH CONCURRENT EXPOSURE TO LONG WAVELENGTH UV IN ZEA MAYS ROOT TIP CELLS

1977 ◽  
Vol 19 (3) ◽  
pp. 447-459 ◽  
Author(s):  
R. S. Verma ◽  
J. E. Cummins ◽  
D. B. Walden
Keyword(s):  
Zea Mays ◽  
Chromosome Aberrations ◽  
Cesium Chloride ◽  
Root Tip ◽  
Chromosome Damage ◽  
Root Tips ◽  
Long Wavelength ◽  
Small Pool ◽  
Tip Cells ◽  
Root Tip Cells

The influence of bromodeoxyuridine (BrUrdR) on the pattern and level of chromosome damage in Zea mays L. root tip cells is described. In some experiments long wavelength ultraviolet light was employed to convert the bromodeoxyuridine in DNA to its photoproduct. BrUrdR treatment produced a marked decrease in the mitotic index and a high proportion of the mitotic cells bore chromosome damage. Following a BrUrdR treatment of 5 h the proportion of damaged cells increased from 20% to 60% during the 20 h following treatment; then the proportion decreased sharply to less than 20%. Root tips treated as above followed by an exposure to long wavelength ultraviolet radiation (UV) had a proportion of damaged cells (80% at 20 h) only slightly greater than those not exposed to UV up to 20 h after treatment. Unlike the unirradiated BrUrdR substituted root tips, the proportion of damaged cells remained high 25 h after treatment. Furthermore, the spectrum of chromosome aberrations differed between irradiated and unirradiated BrUrdR substituted cells. Root tips exposed to long wavelength UV alone showed some damage that was limited to a stage in the cell cycle of irradiated root tips. Analysis of the BrUrdR treated corn DNA by cesium chloride density centrifugation showed that BrUrdR substitution for thymidine in DNA was extensive. Further experiments demonstrated that a large BrUrdR pool was not carried into the rounds of replication following BrUrdR removal from the medium. Nevertheless a small pool of halogenated pyrimidine was observable after BrUrdR removal from the medium.

Persistence of Nucleolar Material During Mitosis in Root Meristematic Cells of Allium sativum

1974 ◽  
Vol 32 ◽  
pp. 272-273
Author(s):  
L. Hanzely
Keyword(s):  
Cell Division ◽  
Allium Sativum ◽  
Animal Species ◽  
Root Tip ◽  
Late Prophase ◽  
Meristematic Cells ◽  
Nucleolar Material ◽  
Root Meristematic Cells ◽  
Tip Cells ◽  
Root Tip Cells

Nucleoli are generally thought to be organelles lacking a continuity during cell division, i.e., they disperse during late prophase and reform within the daughter nuclei at telophase. Recently, however, nucleoli have been shown to persist during mitosis in several plant and animal species (e.g., references 1-4). In this report, evidence is presented indicating the persistence of nucleolar material throughout mitosis in root tip cells of Allium sativum.

scholarly journals Protective Effects of Quercetin against Dimethoate-Induced Cytotoxicity and Genotoxicity in Allium sativum Test

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Waseem Ahmad ◽  
Sibhghatulla Shaikh ◽  
Nazia Nazam ◽  
Mohammad Iqbal Lone
Keyword(s):  
Allium Sativum ◽  
Biological Properties ◽  
Protective Role ◽  
Root Tip ◽  
Protective Effects ◽  
Meristematic Cells ◽  
Plant Test ◽  
Tip Cells ◽  
Dose Dependent ◽  
Root Tip Cells

The present investigation was directed to study the possible protective activity of quercetin—a natural antioxidant against dimethoate-induced cyto- and genotoxicity in meristematic cells of Allium sativum. So far there is no report on the biological properties of quercetin in plant test systems. Chromosome breaks, multipolar anaphase, stick chromosome, and mitotic activity were undertaken in the current study as markers of cyto- and genotoxicity. Untreated control, quercetin controls (@ 5, 10 and 20 μg/mL for 3 h), and dimethoate exposed groups (@ 100 and 200 μg/mL for 3 h) were maintained. For protection against cytogenotoxicity, the root tip cells treated with dimethoate at 100 and 200 μg/mL for 3 h and quercetin treatment at 5, 10, and 20 μg/mL for 16 h, prior to dimethoate treatment, were undertaken. Quercetin was found to be neither cytotoxic nor genotoxic in Allium sativum control at these doses. A significant increase P<0.05 in chromosomal aberrations was noted in dimethoate treated Allium. Pretreatment of Allium sativum with quercetin significantly P<0.05 reduced dimethoate-induced genotoxicity and cytotoxicity in meristematic cells, and these effects were dose dependent. In conclusion, quercetin has a protective role in the abatement of dimethoate-induced cyto- and genotoxicity in the meristematic cells of Allium sativum that resides, at least in part, on its antioxidant effects.

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