Cell growth, wall deposition, and correlated fine structure of colchicine-treated lettuce hypocotyl cells

1977 ◽  
Vol 55 (8) ◽  
pp. 902-917 ◽  
Author(s):  
L. M. Srivastava ◽  
V. K. Sawhney ◽  
M. Bonettemaker

The effects of colchicine, singly and in combination with gibberellic acid (GA3), on growth of lettuce hypocotyl cells are reported. After 72 h of growth, the cells in GA3 are extremely long and cylindrical, whereas those in GA3 + colchicine are very large and more or less isodiametric. The cell volume in colchicine is not significantly different from that in the water control. Kinetic data on cell growth and on dry weight of cell walls indicate a parallelism between the GA3 and GA3 + colchicine treatments and between the colchicine treatment and water control. In all treatments, certain cytological changes, viz. proliferation of dictyosomes and their vesicles, increase in endoplasmic reticulum (ER) and polyribosomes, and increased connections between the ER and plasmalemma, occur at the same time as in the water conrol and proceed ahead of evident cell growth. Changes in wall fibrils and microtubules are described. It is concluded that colchicine does not inhibit the kinetics of cell growth or the deposition of wall material, but since it causes dissolution of microtubules, the deposition of new wall fibrils is random even though it shows some degree of order, and if at that time the cells are growing rapidly under the influence of GA3, they become spherical. These results are discussed with a view to understanding the mechanisms underlying cell enlargement.

1980 ◽  
Vol 26 (2) ◽  
pp. 115-120 ◽  
Author(s):  
G. D. Sprott ◽  
R. C. McKellar

Dithiothreitol reacted, at pH 9.0, with the isolated cell walls of Methanospirillum hungatii, to release about 23% of the cell wall dry weight as a high molecular weight fraction (> 0.5 million daltons). Untreated walls consisted of 70% amino acids, 11% lipid, and 6.6% carbohydrate. Sugars were identified as rhamnose, ribose, glucose, galactose, and mannose. The wall material that was released contained only 47% amino acids and was enriched in lipid, glucose, and phosphate. These results support data from electron micrographs, showing the localized release of cell wall material by the disulfide bond-breaking reagent at alkaline pH. In amino acid composition the untreated walls did not differ greatly from the material released by dithiothreitol, but differed considerably from the walls of another strain of M. hungatii. The ratios of the amino acids found in the cell wall proteins of several archaebacteria and of Bacillus cereus spore coats were similar.


1971 ◽  
Vol 17 (12) ◽  
pp. 1561-1565 ◽  
Author(s):  
K. L. Chung

Bacillus cereus incubated for 4 h in a synthetic medium containing chloramphenicol was observed to form cell walls 2 to 3 times as thick as those from control cells growing in the same medium containing no antibiotic. Then the cells were washed and reincubated in fresh synthetic medium and the ultra-structural changes in the thickened walls during cell growth and elongation were examined by electron microscopy. After incubation for 20 min, multiple ruptured sites and internal fractures appeared randomly on the surface of the thickened cell wall. Large and small pieces of thickened wall fragments soon "peeled off" from the surface, leaving behind a deeper layer of wall material. Normal cell growth and elongation resumed after partial removal of the thickened cell wall. After several generations, thickened wall fragments were not observed on the surface of daughter cells.


2020 ◽  
Vol 62 ◽  
pp. 85-90
Author(s):  
L. V. Tashmatova ◽  
O. V. Matsneva ◽  
T. M. Khromova ◽  
V. V. Shakhov

The article presents methods of experimental polyploidy of fruit, berry and ornamental plants. The purpose of this review is to highlight the problems and prospects of polyploidization of plants in the open ground and in vitro culture and the possibility of their application for apple trees. For the purpose of obtaining apple tetraploids as donors of diploid gametes, seed seedlings were treated with a solution of colchicine in concentrations of 0.1-0.4 % for 24 and 48 hours. Colchicine concentrations of 0.3 % and 0.4 % at 48 hours of treatment had a detrimental eff ect on their development. As a result, tetraploids and chimeras were obtained from seeds from free pollination of the varieties Orlik, Svezhest, Kandil Orlovsky, as well as from seeds obtained from crossing the varieties Svezhest×Bolotovskoe, Moskovskoe Оzherel’e×Imrus, Girlyanda×Venyaminovskoe. The optimal concentration of colchicine was 0.1 %. Methods of colchicine treatment have been studied: 1) adding to the nutrient medium, colchicine concentration: 0.01%, 0.02%, exposure time 24h-19 days; 2) applying amitotic solution to the growth point, colchicine concentration: 0.1 %, 0.2 %, exposure time 24h-7 days. To increase the penetration of colchicine through the cell walls, a 0.1 % dimexide solution was used. Studies have shown that high concentrations and prolonged exposure to colchicine reduce the viability of explants.


Crop Science ◽  
1992 ◽  
Vol 32 (3) ◽  
pp. 806-810 ◽  
Author(s):  
John H. Grabber ◽  
Gerald A. Jung ◽  
Stephen M. Abrams ◽  
Diantha B. Howard

2020 ◽  
Vol 50 (3) ◽  
pp. 460-469
Author(s):  
Damir Zyaitdinov ◽  
Alexandr Ewteew ◽  
Anna Bannikova

Introduction. Bioactive compounds are a very popular topic of modern food science, especially when it concerns obtaining polyphenols from cereals. The antiradical, antioxidant, and anti-inflammatory properties of these ingredients allow them to inhibit and prevent coronary, artery, and cardiovascular diseases, as well as several types of cancer. Encapsulation is an effective technology that protects bioactive ingredients during processing and storage. In addition, it also prevents any possible interaction with other food constituents. The research objective was to obtain effective tools of controlled delivery of bioactive compounds. The study featured whey protein as a wall material in combination with maltodextrin to encapsulate the bioactives from oat bran. Study objects and methods. The processed material was oat bran. The technology of its biotransformation was based on ultrasound processing and enzymatic hydrolysis. The antioxidant properties were determined using a coulometer of Expert – 006-antioxidants type (Econix-Expert LLC, Moscow, Russia). Separation and quantitative determination of extract were followed using a Stayer HPLC device (Akvilon, Russia) and a system column Phenomenex Luna 5u C18(2) (250×4.6 mm). The total phenolic content was measured by a modified Folin-Ciocalteu method. To prepare microcapsules, whey protein concentrate (WPC) and maltodextrin (MD) solutions were mixed at ratios 6:4, 4:6, and 5:5. After that, the mixes were treated by ultrasonication and 10% w/w of guar gum solution as double wall material. The encapsulation efficiency (EE) was determined as a ratio of encapsulated phenolic content to total phenolic content. A digestion protocol that simulates conditions of the human gastric and intestinal tract was adapted to investigate the release kinetics of the extracts. Results and discussion. Ferulic acid is the main antioxidant in cereals. Its amount during extraction was consistent with published data: 9.2 mg/mL after ultrasound exposure, 9.0 mg/mL after enzymatic extraction, and 8.6 mg/mL after chemical treatment. The antioxidant activity of the obtained polyphenols was quite high and reached 921 cu/mL. It depended on the concentration of the preparation in the solution and the extraction method. The polyphenols obtained by ultrasonic exposure and enzyme preparations proved to have a more pronounced antioxidant activity. The highest EE (95.28%) was recorded at WPC:MD ratio of 60:40. In vitro enzymatic hydrolysis protocol simulating digestion in the gastrointestinal tract was used to study the effect of capsule structural characteristics on the kinetics of polyphenol release. The percentage of o polyphenols released from capsules ranged from 70% to 83% after two hours of digestion, which confirmed the effectiveness of microencapsulation technology. Conclusion. The research confirmed the possibility of using polyphenols obtained by the biotechnological method from oat bran as functional ingredients. Eventually, they may be used in new functional products with bifidogenic properties. Whey protein can be used to encapsulate polyphenols as the wall material of microcapsules.


2018 ◽  
Vol 15 (8) ◽  
pp. 513
Author(s):  
Ewen Silvester ◽  
Annaleise R. Klein ◽  
Kerry L. Whitworth ◽  
Ljiljana Puskar ◽  
Mark J. Tobin

Environmental contextSphagnum moss is a widespread species in peatlands globally and responsible for a large fraction of carbon storage in these systems. We used synchrotron infrared microspectroscopy to characterise the acid-base properties of Sphagnum moss and the conditions under which calcium uptake can occur (essential for plant tissue integrity). The work allows a chemical model for Sphagnum distribution in the landscape to be proposed. AbstractSphagnum is one the major moss types responsible for the deposition of organic soils in peatland systems. The cell walls of this moss have a high proportion of carboxylated polysaccharides (polygalacturonic acids), which act as ion exchangers and are likely to be important for the structural integrity of the cell walls. We used synchrotron light source infrared microspectroscopy to characterise the acid-base and calcium complexation properties of the cell walls of Sphagnum cristatum stems, using freshly sectioned tissue confined in a flowing liquid cell with both normal water and D2O media. The Fourier transform infrared spectra of acid and base forms are consistent with those expected for protonated and deprotonated aliphatic carboxylic acids (such as uronic acids). Spectral deconvolution shows that the dominant aliphatic carboxylic groups in this material behave as a monoprotic acid (pKa=4.97–6.04). The cell wall material shows a high affinity for calcium, with a binding constant (K) in the range 103.9–104.7 (1:1 complex). The chemical complexation model developed here allows for the prediction of the chemical environment (e.g. pH, ionic content) under which Ca2+ uptake can occur, and provides an improved understanding for the observed distribution of Sphagnum in the landscape.


Horticulturae ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 38
Author(s):  
Naji K. Al-Mefleh ◽  
Yahia A. Othman ◽  
Maher J. Tadros ◽  
Amani Al-Assaf ◽  
Samer Talozi

This study investigated the influence of treated greywater on growth and protein content of multipurpose (forage and ornamental) transplants, Prosopis juliflora L., Prosopis tamarugo L., and Albizia lebbeck L. Transplants of tested species were irrigated with treated greywater, diluted greywater (grey + distilled water, 1:1/by volume), and distilled water (control) for seven months. Water quality analysis showed that the concentrations of nutrients and heavy metals found in the greywater were within the acceptable range compared with Jordan Institution for Standard and Metrology (JISM) and the World Health Organization (WHO) thresholds for safe use of greywater. Escherichia coli found in the greywater were lower compared to JISM and WHO guidelines for the safe use of greywater. Irrigation with treated greywater increased shoot fresh weight by 24–39% and dry weight by 34–40% compared to diluted greywater and control. No significant difference in crude protein was noticed between water treatments. Prosopis species (P. juliflora Albizia lebbeck L. and P. tamarugo Albizia lebbeck L.) had higher shoot fresh (35%) and dry weight the same species had lower crude protein (44%) when compared to Albizia lebbeck Albizia lebbeck L. The reuse of treated greywater for landscaping or forage production alleviates the demand for water resources and reduces the pressure on wastewater treatment plants. However, considering the controversial findings of previous studies on greywater quality (especially, long-term reuse), the reuse of treated greywater needs to be considered with caution and periodic quality analyses and economic assessments are required.


2021 ◽  
Vol 27 (1) ◽  
pp. 1-12
Author(s):  
Bilal Ahmad Khan ◽  
Saima Anwar ◽  
Rizwan Maqbool Maqbool ◽  
Muhammad Mohsin Amin ◽  
Muhammad Mansoor Javaid ◽  
...  

ABSTRACT Aqueous extracts of plants are used to control weeds and having no hazards to environment and are inexpensive. Present study was undertaken to investigate the effect of aqueous extracts of Sonchus oleraceus L. on the Oryza punctata L. emergence and initial seedling growth. It consists of aqueous extract of leaves, stem and fruit of S. oleraceus at varying concentrations 0.25, 0.50, 1, 2, 4 and 8 % (w/v) along with a distilled water control. The allelochemicals present in the aqueous extracts showed stimulatory, inhibitory and hormetic responses depending upon the concentration and the plant part. Results directed that maximum mean emergence time (5.26 days) and minimum germination index (1.67), germination percentage (40%), seedling fresh weight (59 g) and dry weight (8 g) of O. punctata were examined with 8% aqueous extract of S. oleraceus fruit. However, 4% aqueous extract of S. oleraceus fruit produced minimum root length (5.71). On the basis this experiment it was concluded that 8% aqueous extract of S. oleraceus fruit can be used for controlling O. punctata weed. Keywords: Aqueous extract, environment, allelochamicals, hermetic response, stimulatory ABSTRACT Aqueous extracts of plants are used to control weeds and having no hazards to environment and are inexpensive. Present study was undertaken to investigate the effect of aqueous extracts of Sonchus oleraceus L. on the Oryza punctata L. emergence and initial seedling growth. It consists of aqueous extract of leaves, stem and fruit of S. oleraceus at varying concentrations 0.25, 0.50, 1, 2, 4 and 8 % (w/v) along with a distilled water control. The allelochemicals present in the aqueous extracts showed stimulatory, inhibitory and hormetic responses depending upon the concentration and the plant part. Results directed that maximum mean emergence time (5.26 days) and minimum germination index (1.67), germination percentage (40%), seedling fresh weight (59 g) and dry weight (8 g) of O. punctata were examined with 8% aqueous extract of S. oleraceus fruit. However, 4% aqueous extract of S. oleraceus fruit produced minimum root length (5.71). On the basis this experiment it was concluded that 8% aqueous extract of S. oleraceus fruit can be used for controlling O. punctata weed. Keywords: Aqueous extract, environment, allelochamicals, hermetic response, stimulatory ABSTRACT Aqueous extracts of plants are used to control weeds and having no hazards to environment and are inexpensive. Present study was undertaken to investigate the effect of aqueous extracts of Sonchus oleraceus L. on the Oryza punctata L. emergence and initial seedling growth. It consists of aqueous extract of leaves, stem and fruit of S. oleraceus at varying concentrations 0.25, 0.50, 1, 2, 4 and 8 % (w/v) along with a distilled water control. The allelochemicals present in the aqueous extracts showed stimulatory, inhibitory and hormetic responses depending upon the concentration and the plant part. Results directed that maximum mean emergence time (5.26 days) and minimum germination index (1.67), germination percentage (40%), seedling fresh weight (59 g) and dry weight (8 g) of O. punctata were examined with 8% aqueous extract of S. oleraceus fruit. However, 4% aqueous extract of S. oleraceus fruit produced minimum root length (5.71). On the basis this experiment it was concluded that 8% aqueous extract of S. oleraceus fruit can be used for controlling O. punctata weed. Keywords: Aqueous extract, environment, allelochamicals, hermetic response, stimulatory


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