scholarly journals The Effect of Extended Anaerobic Treatments on the Chromosomes of Vicia faba

1959 ◽  
Vol 5 (1) ◽  
pp. 135-142 ◽  
Author(s):  
Timothy Merz
Keyword(s):  
Energy Source ◽  
Vicia Faba ◽  
Lateral Root ◽  
Root Tip ◽  
Combined Treatments ◽  
Aberration Frequency ◽  
Alternative Hypotheses ◽  
Fermentation Inhibitor ◽  
High Concentrations ◽  
Energy Deprivation

The effects of extended anaerobic treatments on Vicia faba lateral root-tip chromosomes were determined. It was observed that aberrations resulted from these treatments, and that the frequency varied from root to root as well as from experiment to experiment. It was suggested that the inconsistency observed might be due to variation in the abilities of different roots to produce energy via fermentation routes. If this were true, an inhibition of fermentation would result in a more consistent aberration frequency. A fermentation inhibitor, NaF, was used in combination with extended anaerobic treatments. The observed frequency of aberrations after the combined treatments was generally higher and considerably less variable. Although other hypotheses might account for the NaF effect, the hypothesis most compatible with the evidence is that the effect is due to energy deprivation. The experimental results are discussed in terms of the aforementioned effect and in terms of three alternative hypotheses for the production of chromosomal aberrations as a consequence of a lack of energy. It is concluded that damage might result from a build-up of normal cellular compounds to abnormally high concentrations which would act directly or indirectly on the chromosomes, from the breakdown of DNA as an energy source, or simply as a result of the fact that the chromosome needs energy to remain intact.

Effect of Mitomycin C on Lateral Root-Tip Chromosomes of Vicia faba

Science ◽  
1961 ◽  
Vol 133 (3449) ◽  
pp. 329-330
Author(s):  
Timothy Merz
Keyword(s):  
Mitomycin C ◽  
Vicia Faba ◽  
Lateral Root ◽  
Root Tip

‘Clastogenic adaptation’ of the Vicia faba root-tip meristem as affected by various treatment parameters

1984 ◽  
Vol 140 (2-3) ◽  
pp. 99-102 ◽  
Author(s):  
R. Rieger ◽  
A. Michaelis ◽  
H. Nicoloff
Keyword(s):  
Vicia Faba ◽  
Root Tip

scholarly journals Multiwalled carbon nanotubes in alfalfa and wheat: toxicology and uptake

2012 ◽  
Vol 9 (77) ◽  
pp. 3514-3527 ◽  
Author(s):  
Pola Miralles ◽  
Errin Johnson ◽  
Tamara L. Church ◽  
Andrew T. Harris
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Root Elongation ◽  
Wheat Root ◽  
Root Tip ◽  
Multiwalled Carbon ◽  
Wheat Seedlings ◽  
Industrial Grade ◽  
High Concentrations ◽  
Multiwalled Cnts

Data on the bioavailability and toxicity of carbon nanotubes (CNTs) in the environment, and, in particular, on their interactions with vascular plants, are limited. We investigated the effects of industrial-grade multiwalled CNTs (75 wt% CNTs) and their impurities on alfalfa and wheat. Phytotoxicity assays were performed during both seed germination and seedling growth. The germinations of both species were tolerant of up to 2560 mg l −1 CNTs, and root elongation was enhanced in alfalfa and wheat seedlings exposed to CNTs. Remarkably, catalyst impurities also enhanced root elongation in alfalfa seedlings as well as wheat germination. Thus the impurities, not solely the CNTs, impacted the plants. CNT internalization by plants was investigated using electron microscopy and two-dimensional Raman mapping. The latter showed that CNTs were adsorbed onto the root surfaces of alfalfa and wheat without significant uptake or translocation. Electron microscopy investigations of internalization were inconclusive owing to poor contrast, so Fe 3 O 4 -functionalized CNTs were prepared and studied using energy-filter mapping of Fe 3 O 4 . CNTs bearing Fe 3 O 4 nanoparticles were detected in the epidermis of one wheat root tip only, suggesting that internalization was possible but unusual. Thus, alfalfa and wheat tolerated high concentrations of industrial-grade multiwalled CNTs, which adsorbed onto their roots but were rarely taken up.

scholarly journals Lateral Root Priming Synergystically Arises from Root Growth and Auxin Transport Dynamics

2018 ◽  
Author(s):  
Thea van den Berg ◽  
Kirsten H. ten Tusscher
Keyword(s):  
Cell Cycle ◽  
Root Growth ◽  
Lateral Root ◽  
Root Formation ◽  
Growth Dynamics ◽  
Root Tip ◽  
Cycle Duration ◽  
Elongation Zone ◽  
Lateral Root Formation ◽  
Cell Cycle Duration

AbstractThe root system is a major determinant of plant fitness. Its capacity to supply the plant with sufficient water and nutrients strongly depends on root system architecture, which arises from the repeated branching off of lateral roots. A critical first step in lateral root formation is priming, which prepatterns sites competent of forming a lateral root. Priming is characterized by temporal oscillations in auxin, auxin signalling and gene expression in the root meristem, which through growth become transformed into a spatially repetitive pattern of competent sites. Previous studies have demonstrated the importance of auxin synthesis, transport and perception for the amplitude of these oscillations and their chances of producing an actual competent site. Additionally, repeated lateral root cap apoptosis was demonstrated to be strongly correlated with repetitive lateral root priming. Intriguingly, no single mutation has been identified that fully abolishes lateral root formation, and thusfar the mechanism underlying oscillations has remained unknown. In this study, we investigated the impact of auxin reflux loop properties combined with root growth dynamics on priming, using a computational approach. To this end we developed a novel multi-scale root model incorporating a realistic root tip architecture and reflux loop properties as well as root growth dynamics. Excitingly, in this model, repetitive auxin elevations automatically emerge. First, we show that root tip architecture and reflux loop properties result in an auxin loading zone at the start of the elongation zone, with preferential auxin loading in narrow vasculature cells. Second, we demonstrate how meristematic root growth dynamics causes regular alternations in the sizes of cells arriving at the elongation zone, which subsequently become amplified during cell expansion. These cell size differences translate into differences in cellular auxin loading potential. Combined, these properties result in temporal and spatial fluctuations in auxin levels in vasculature and pericycle cells. Our model predicts that temporal priming frequency predominantly depends on cell cycle duration, while cell cycle duration together with meristem size control lateral root spacing.

scholarly journals Strigolactones Control Root System Architecture and Tip Anatomy in Solanum lycopersicum L. Plants under P Starvation

Plants ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 612 ◽  
Author(s):  
Veronica Santoro ◽  
Michela Schiavon ◽  
Francesco Gresta ◽  
Andrea Ertani ◽  
Francesca Cardinale ◽  
...  
Keyword(s):  
Solanum Lycopersicum ◽  
Lateral Root ◽  
Primary Root ◽  
Root Traits ◽  
Root System Architecture ◽  
Root Tip ◽  
Root Number ◽  
Wild Type ◽  
Solanum Lycopersicum L ◽  
P Supply

The hormones strigolactones accumulate in plant roots under phosphorus (P) shortage, inducing variations in plant phenotype. In this study, we aimed at understanding whether strigolactones control morphological and anatomical changes in tomato (Solanum lycopersicum L.) roots under varying P supply. Root traits were evaluated in wild-type seedlings grown in high vs. low P, with or without exogenous strigolactones, and in wild-type and strigolactone-depleted plants grown first under high vs. no P, and then under high vs. no P after acclimation on low P. Exogenous strigolactones stimulated primary root and lateral root number under low P. Root growth was reduced in strigolactone-depleted plants maintained under continuous P deprivation. Total root and root hair length, lateral root number and root tip anatomy were impaired by low strigolactone biosynthesis in plants grown under low P or transferred from low to no P. Under adequate P conditions, root traits of strigolactone-depleted and wild-type plants were similar. Concluding, our results indicate that strigolactones (i) control macro- and microscopic changes of root in tomato depending on P supply; and (ii) do not affect root traits significantly when plants are supplemented with adequate P, but are needed for acclimation to no P and typical responses to low P.

scholarly journals Suppression effect of CIPC on nucleoli in Vicia faba root tip cells.

CYTOLOGIA ◽  
1987 ◽  
Vol 52 (3) ◽  
pp. 639-645
Author(s):  
Yoshio Yoshida ◽  
Ichiro Hatayama
Keyword(s):  
Vicia Faba ◽  
Root Tip ◽  
Suppression Effect ◽  
Tip Cells ◽  
Root Tip Cells
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