scholarly journals Effects of High g Values on Growth and Chlorophyll Content in Hydrated and Dehydrated Wheat Seeds

2020 ◽  
Vol 21 (2) ◽  
pp. 82
Author(s):  
Sagar Shankar Jagtap ◽  
P. B. Vidyasagar
Keyword(s):  
Chlorophyll Content ◽  
Centrifugal Force ◽  
Present Observation ◽  
Water Medium ◽  
Gravitational Acceleration ◽  
Initial Experiment ◽  
Agar Gel ◽  
Wheat Seedlings ◽  
G Value ◽  
Wheat Seeds

Higher g value stimuli (gravitational acceleration more than 1 g and referred as hyper gravity) caused by centrifugation have been shown to inhibit elongation growth of various plants. In the present study, effects of high g values were studied on wheat seeds with and without water medium at the time of exposure to high g values. Wheat seeds (variety: LOK-1) were washed with 0.5% fungicide and then 4-5 times with distilled water (D/W). Seeds were then soaked in D/W for 24 hrs. Two different experiments were performed. In initial experiment, soaked seeds were taken into the centrifuge tubes filled with 1 ml D/W. Seeds were exposed to hypergravity ranging from 500 g to 2500 g for 10 minutes. In another experiment, soaked seeds were taken into the centrifuge tubes without water or any other medium and then exposed to high g values. After exposure seeds were immediately sowed on 0.8% agar gel. Results obtained showed that exposure to high g values suppressed growth in wheat seedlings when seeds were exposed to high g values with water as a medium. Chlorophyll content also decreased with increase in g. However, no change in growth and chlorophyll content were observed when seeds were exposed without water medium up to g values as high as 2500. Thus, effects of high g value stimuli depend not only on how much centrifugal force is applied to the seeds but also depends upon how much force is experienced by the inner part of the seeds.  Present observation shows that effective centrifugal force experienced by the seeds is different when applied with and without medium.

scholarly journals An important source of preanalytical error in medical laboratories: centrifugation

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Cigdem Sonmez ◽  
Alper Gümüş ◽  
Mehmet Senes ◽  
Guzin Aykal ◽  
Fatma Taneli ◽  
...  
Keyword(s):  
Centrifugal Force ◽  
Gravitational Acceleration ◽  
Medical Laboratories ◽  
Electric Device ◽  
Preanalytical Phase ◽  
Plasma And Urine Samples ◽  
Relative Centrifugal Force ◽  
Technical Specifications ◽  
Physical Impact ◽  
Rotor Type

Abstract Centrifugation separates particles within the specimen according to their shape, dimensions, and density and basically can be defined as a separation method. The centrifuge is an essential device in medical laboratories to prepare the serum, plasma, and urine samples for analysis. It is basically an electric device composed of the stationary (motor) and the motile (rotor) part. The centrifugation depends on two main variables: relative centrifugal force (RCF) and centrifugation time. The physical impact separating the specimen into its components in the centrifuge known as RCF is expressed as the multiples of gravitational acceleration (×g). RPM, defined as the number of rotations of the centrifuge per minute, shows the speed of the centrifuge. RCF value can be calculated by using RPM, and the centrifuge radius. Because models and sizes of centrifuges vary considerably, the use of gravity (g) forces instead of RPM is suggested. The centrifuges can be classified according to their usage, speed, technical specifications, and rotor type. An accurate and precise centrifugation process is essential to prevent errors in the preanalytical phase. The purpose of this document is to ensure the standardization of a good, precise protocol for the centrifugation process among the medical laboratories.

Antioxidant enzymes in germinating wheat seeds as affected by dehydration stress, ABA and hydrogen peroxide

2008 ◽  
Vol 56 (2) ◽  
pp. 113-127 ◽  
Author(s):  
S. Sabeva ◽  
D. Nedeva
Keyword(s):  
Antioxidant Enzymes ◽  
Low Temperature ◽  
Peroxidase Activity ◽  
Wheat Seedling ◽  
Temperature Treatment ◽  
Dehydration Stress ◽  
Stress Factors ◽  
Wheat Seedlings ◽  
Low Temperature Treatment ◽  
Wheat Seeds

The response of the antioxidant enzymes peroxidase [EC 1.11.1.11], superoxide dismutase (SOD) [EC 1.15.1.1] and catalase [EC 1.11.1.6] to dehydration stress caused by low and high temperature, salinity (0.2 M NaCl) and hyperosmoticum (0.5 M sucrose), as well as to exogenous ABA and H 2 O 2 , was examined in germinating wheat seeds. The data presented here confirm and complete previous results for other stages of wheat seedling development (Bakalova et al., 2004; 2007). Catalase was the most susceptible antioxidant enzyme under the chronic stress conditions applied. Its activity correlated closely to the decrease in the growth rate of wheat seedlings. Low temperature had the strongest effect of all the stress factors applied. There was a significant decrease in anionic peroxidase activity, accompanied by catalase inhibition, after low temperature treatment. An analysis of all the data obtained revealed that the treatments had mostly non-specific effects on gene expression, protein and enzyme profiles. Catalase and peroxidase activity were suppressed not only by low temperature, but by hyperosmoticum (0.5 M sucrose) as well. This result confirmed findings that a significant number of genes induced by one particular stress are also upregulated by other stresses (Kreps et al., 2002; Munns, 2002; Rabbani et al., 2003).

Chlorophyll Content of Gibberellin-Treated Wheat Seedlings

Nature ◽  
1960 ◽  
Vol 186 (4720) ◽  
pp. 217-218 ◽  
Author(s):  
FREDERICK T. WOLF ◽  
ALAN H. HABER
Keyword(s):  
Chlorophyll Content ◽  
Wheat Seedlings

scholarly journals Sedimentation of the virus of foot-and-mouth disease in the Sharples-Super Centrifuge

1937 ◽  
Vol 37 (3) ◽  
pp. 445-462 ◽  
Author(s):  
M. Schlesinger ◽  
I. A. Galloway
Keyword(s):  
Centrifugal Force ◽  
Sedimentation Rate ◽  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
Host Protein ◽  
Sedimentation Equilibrium ◽  
Rate Data ◽  
Agar Gel ◽  
Virus Particles ◽  
Foot And Mouth

1. By means of a new technique, using the “closed bowl” of the Sharpies-Super Centrifuge, in which the distance which the virus particles have to travel under the influence of a given centrifugal force until they are caught mechanically in an agar-gel lining the wall of the bowl amounts to only a few tenths of a millimetre, the potency of 5 c.c. of a foot-and-mouth disease virus suspension can be reduced by 90–99 per cent in 3 min. using a centrifugal force of 24,000 times gravity. The virus can be recovered without loss by extraction of the agar-gel either in fresh medium or even in the liquid layer or “supernatant”, thus showing that adsorption phenomena play no role whatever in the effects obtained by centrifugation.2. The non-adsorbability of the virus by the agar, however, is determined by the presence of a certain though very small amount of impurities presumably protein which seem to have a “protective” effect. The limit of nonadsorption of the virus by the gel appears to be in that region of “purity” where the sulphosalicylic acid test for protein is negative whereas serological precipitation reactions for host protein are still positive. Virus purified beyond this limit is strongly adsorbed by an agar-gel.3. Measurements of the sedimentation rate were made on three strains of virus of different type Vallee A, Vallee 0 and Waldmann C and no differences between the three strains were observed. The average diameter of the virus particles determined from the sedimentation rate data was 20 mμ. All the evidence now available for the monodispersity of the virus is discussed. The fact that the infective particles are uniform in size indicates that the measurements recorded here concern actually the single virus elements.4. The sedimentation equilibrium of the virus has been estimated. The value calculated on this basis for the weight of a single virus particle is circ. 1 × 10−17 g. The diameter of a sphere of this weight and density 1·30 would be 25 mμ. The size values for the virus, 25 mμ estimated from sedimentation equilibrium data and 20 mμ estimated from sedimentation rate data, are discussed in relation to the possible shape of the virus particles.5. The virus can be sedimented in sucrose and sucrose-salt solutions of densities up to 1·28. On the basis of the sedimentation rates in these media the specific gravity of the virus particles is estimated to be about 1·40. This value however may be abnormally high due to the dehydrating effect of the high concentration of salt or sugar. The application of the centrifuge technique described here to the concentration and purification of the virus of foot-andmouth disease in conjunction with ultrafiltration methods will be the subject of a second paper by Galloway & Schlesinger (1937).

scholarly journals Influence of seed treatment on microbiota and development of winter wheat seedlings

2021 ◽  
Vol 11 (1) ◽  
pp. 55-61
Author(s):  
T.O. Rozhkova ◽  
S.V. Stankevych ◽  
A.V. Matsyura
Keyword(s):  
Winter Wheat ◽  
Seed Treatment ◽  
Agar Medium ◽  
Considerable Variability ◽  
Wheat Seedlings ◽  
North East ◽  
The North ◽  
Chemical Agents ◽  
Growth Of Seedlings ◽  
Wheat Seeds

The microbiota of winter wheat seeds from the North-East of Ukraine was studied by a biological method. Its considerable variability is established over three years (2017–2019). The effect of the treatment agents on most microorganisms of wheat seed microbiota in Ukraine, rather than on its genera and species, is shown. It has been proven that fungicides deleted some species and did not affect the development of others. Chemicals replaced some species or genera of fungi with others or even other microorganisms. Biological seed treatment (Phytosporin-M) has caused less microbiota change than chemical treatment (Maxim 0.25 FS, Rostock, Kinto Duo). Fungicides have replaced the dominance of Alternaria spp. (2017 – 57.8%, 2018 – 63.5%) for the dominance of yeast (Rostock – 54%) and Aureobasidium pullulans (Maxim 0.25 FS – 84.2%) in 2017, bacteria (Maxim 0.25 FS – 72.3%, Rostock – 53.8%) – in 2018. A. pullulans dominated in the microbiota of winter wheat seeds in 2019. The highest amount of A. pullulans was noted for the treatment of seeds by Phytosporin-M (85.9%). The biological seed treatment reduced the amount of Nigrospora spp. and Alternaria spp. Several times (3 and 5, respectively), chemical agents did not give Nigrospora spp. germination reduced the amount of A. pullulans, Alternaria spp. in 2019. Maxim 0.25 FS, Rostock 50%, and Kinto Duo delayed seed germination and seedling development on agar medium and soil, whereas Phytosporin-M – on the contrary, promoted the growth of seedlings and significantly exceeded control.

scholarly journals Stimulating Properties Derivatives of Glycyrrhizic Acid

2020 ◽  
Vol 6 (11) ◽  
pp. 206-212
Author(s):  
M. Allaniyazova ◽  
U. Shapulatov ◽  
Kh. Kushiev
Keyword(s):  
Glycyrrhizic Acid ◽  
Wheat Plant ◽  
Wheat Root ◽  
Root Apical Meristem ◽  
Root Cells ◽  
Wheat Seedlings ◽  
Hormonal System ◽  
Post Stress ◽  
Wheat Seeds

The article presents the results of the influence of glycyrrhizic acid and its derivatives in various percentages (0.1–1.5%) NaCl and in the post-stress period on the balance of phytohormones and the growth of roots of wheat seedlings. It was found that the treatment of wheat seeds with glycyrrhizic acid prevented salinization-induced inhibition of the mitotic activity of the cells of the root apical meristem and, in the post-stress period, accelerated the repair of root growth processes. The manifestation of the protective effect of glycyrrhizic acid on the growth of wheat root cells is due to its effect on the activity of the hormonal system of seedlings. Salinity negatively affected the balance of phytohormones associated with reversible accumulation of ABA and a decrease in the level of IAA and cytokinins in wheat seedlings. Treatment of wheat seeds with glycyrrhizic acid and its derivatives contributed to the maintenance of the hormonal status of roots under salinity conditions at the level of control plants. The results obtained indicate an important role of glycyrrhizic acid induced rearrangements of the hormonal system in the regulation of wheat plant growth under stress conditions.

INFLUENCE OF A NANOSEILE ON THE CONTENTS OF K+, Nа+ AND Cl— IONS IN WHEAT SEEDS IN THE CONDITIONS OF THE COMBINED ACTION OF SALTING AND DRAIN

2020 ◽  
Vol 6(72) (1) ◽  
pp. 220-230
Author(s):  
I. N. Yurkova ◽  
A. V. Omelchenko ◽  
A. A. Zubochenko ◽  
D. A. Panov ◽  
I. L. Danilova
Keyword(s):  
Protective Effect ◽  
Water Content ◽  
Water Status ◽  
Soil Salinization ◽  
Water Soluble ◽  
Biologically Active ◽  
River Sand ◽  
Wheat Seedlings ◽  
Leaves And Roots ◽  
Wheat Seeds

Soil salinization is one of the most important problems for agriculture. In most cases, the effect of salinization is manifested in conjunction with water deficiency, reinforcing each other. One of the most dangerous types of salinization is sodium chloride, in which both sodium and chlorine ions have a damaging effect on plants. The physiological processes taking place under stressful conditions with the participation of enzymes and antioxidants are closely related to each other. The content of some enzymes is significantly affected by selenium. The least toxic and bioavailable is selenium in the form of nanoparticles stabilized by natural biologically active substances. The aim of the work was to study the effect of the tread action of the original water-soluble composition of nanosalen stabilized with sodium alginate on the content of K+, Na+ and Cl— ions in wheat seedlings under the combined effects of salinization and drought. The objects of study were winter wheat seeds (Triticum aestivum L.) and a water-soluble composition of selenium nanoparticles. Wheat seeds were soaked for 4 hours in a solution of selenium nanocomposition at a concentration of 10.0; 20.0 and 30.0 mg/l. The control was seeds soaked in distilled water. Plants were grown for 10 days under controlled conditions in a climatic chamber in vessels with a capacity of 1.0 L., a 16-hour photoperiod, a temperature of 25/20 °C (day / night) and a relative humidity of 60±5 %. Well washed river sand was used as a substrate. On day 10, the mass of raw and dry matter and the content of K+, Na+ and Cl— ions in the leaves and roots, as well as on the water content of the leaf tissues and the relative water content (RWC) were determined. For the first time, a study was made of the protective effect of selenium nanocomposite on the content of K+, Na+ and Cl— in leaves and roots, as well as their relationship with the water status of leaves in wheat seedlings under the combined effect of chloride salinity and drought. The action of nanoselen increases the absorption of K+ ions by both roots and leaves. In this case, the absorption of Na+ ions are significantly reduced. The protective effect of nanoselen is also manifested in maintaining a high-water status.

Azospirillum inoculation in pregerminating wheat seeds

1996 ◽  
Vol 42 (1) ◽  
pp. 83-86 ◽  
Author(s):  
Cecilia M. Creus ◽  
Rolando J. Sueldo ◽  
Carlos A. Barassi
Keyword(s):  
Triticum Aestivum ◽  
Azospirillum Brasilense ◽  
Dry Weight ◽  
The Other ◽  
Distilled Water ◽  
Fresh Weight ◽  
Bacterial Concentration ◽  
Wheat Seedlings ◽  
Viable Cells ◽  
Wheat Seeds

Azospirillum cells were inoculated in pregerminating wheat during seed imbibition. Surface-sterilized seeds of Triticum aestivum cv. Buck Pucará were sequentially soaked for 3 h in water and 3 h in the inoculum of 3 × 108Azospirillum brasilense Sp 245 cells∙mL−1, to allow bacteria to enter during imbibition. Germination and seedling growth were accomplished in sterile distilled water at 20 °C, in the dark. To compare with more traditional methods based on plant–Azospirillum colonization after germination, seedlings from noninoculated seeds were inoculated in parallel by immersing roots in the same inoculum, for the same period of time. Autoclaved inocula were used as controls in all cases. We observed about 5 × 108Azospirillum cells∙g−1 fresh weight in 11-day-old wheat seedlings inoculated before or after seed germination. However, roots from seed-inoculated seedlings had higher both bacterial concentration and length. On the other hand, seeds inoculated during imbibition and dried to 14% water content retained 3.7 × 106 viable cells∙g−1 dry weight up to 27 days. Moreover, seeds stored for 30 days were not only able to germinate but also to harbor over 106 cells∙g−1 fresh weight in roots after 7 days growth. Here we present the possibility of obtaining in a simple and inexpensive way, seeds containing high numbers of viable Azospirillum cells, which could avoid the use of external carriers or adhesives.Key words: Azospirillum, wheat, inoculation.

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