THE EFFECT OF TEMPERATURE ON MEIOSIS AND POLLEN DEVELOPMENT IN WHEAT AND RYE

1972 ◽  
Vol 14 (3) ◽  
pp. 615-624 ◽  
Author(s):  
M. D. Bennett ◽  
J. B. Smith ◽  
R. Kemble
Keyword(s):  
Male Sterility ◽  
Chinese Spring ◽  
Pollen Development ◽  
Effect Of Temperature ◽  
Maturation Time ◽  
Pollen Maturation ◽  
Cereal Breeding ◽  
Chinese Spring Wheat ◽  
Increasing Temperature ◽  
Temperature Responses

The durations of meiosis and pollen development were estimated in Petkus Spring rye and Chinese Spring wheat grown at 15, 20 and 25 °C. Over the range 15-25 °C, meiotic duration and pollen maturation time decreased with increasing temperature and the ratio between the durations of these stages at 25 °C and at 15 °C (Q10) indicated that the temperature responses of meiotic and pollen development were similar in both species. Both within and between species meiosis and pollen maturation had constant relative durations at each temperature. The effect of low temperature on the duration of meiosis and pollen development was similar in Holdfast, an extreme type of winter wheat, as in Chinese Spring. The relevance of these results to hybrid cereal breeding are mentioned. In plants grown at 25 °C, abnormal meiotic and pollen development resulting in male sterility was seen in some anthers. The cause of male sterility appeared to be thickening of tapetal cell walls concurrent with abnormal late meiotic development in PMC's.

scholarly journals Effect of temperature on sex expression in onion (Allium cepa L.).

1978 ◽  
Vol 26 (1) ◽  
pp. 41-44
Author(s):  
Q.P. van der Meer ◽  
J.L. van Bennekom
Keyword(s):  
Critical Temperature ◽  
Male Sterility ◽  
Allium Cepa ◽  
Constant Temperature ◽  
Sex Expression ◽  
Effect Of Temperature ◽  
Early Stages ◽  
Allium Cepa L ◽  
Increasing Temperature ◽  
B Lines

At the onset of bolting, eleven populations of the variety Wolska were placed in the greenhouse at constant temperatures of 14, 17, 20 or 23 deg C. The percentage of male-fertile plants increased with increasing temperature, the critical temperature appearing to be 17 deg C. The transference of plants from outside to a constant temperature of 14 deg C, three or six weeks after the initiation of bolting, showed the effect of temperature to decrease with time, suggesting that induction of male sterility occurs in the early stages of bolting. Observations on an unspecified number of A and B lines of the variety Rijnsburg at 14, 20 and 23 deg C indicated that instability of sex expression occurs only in B lines. (Abstract retrieved from CAB Abstracts by CABI’s permission)

scholarly journals Theoretical Effect of Temperature on Threshold in the Hodgkin-Huxley Nerve Model

1966 ◽  
Vol 49 (5) ◽  
pp. 989-1005 ◽  
Author(s):  
Richard Fitzhugh
Keyword(s):  
Relaxation Time ◽  
Relaxation Times ◽  
Giant Axon ◽  
Temperature Curve ◽  
Effect Of Temperature ◽  
Threshold Temperature ◽  
Ionic Conductances ◽  
And Shifts ◽  
The Right ◽  
Increasing Temperature

In the squid giant axon, Sjodin and Mullins (1958), using 1 msec duration pulses, found a decrease of threshold with increasing temperature, while Guttman (1962), using 100 msec pulses, found an increase. Both results are qualitatively predicted by the Hodgkin-Huxley model. The threshold vs. temperature curve varies so much with the assumptions made regarding the temperature-dependence of the membrane ionic conductances that quantitative comparison between theory and experiment is not yet possible. For very short pulses, increasing temperature has two effects. (1) At lower temperatures the decrease of relaxation time of Na activation (m) relative to the electrical (RC) relaxation time favors excitation and decreases threshold. (2) For higher temperatures, effect (1) saturates, but the decreasing relaxation times of Na inactivation (h) and K activation (n) factor accommodation and increased threshold. The result is a U-shaped threshold temperature curve. R. Guttman has obtained such U-shaped curves for 50 µsec pulses. Assuming higher ionic conductances decreases the electrical relaxation time and shifts the curve to the right along the temperature axis. Making the conductances increase with temperature flattens the curve. Using very long pulses favors effect (2) over (1) and makes threshold increase monotonically with temperature.

scholarly journals High Temperatures Cause Male Sterility in Rice Plants with Transcriptional Alterations During Pollen Development

2009 ◽  
Vol 50 (11) ◽  
pp. 1911-1922 ◽  
Author(s):  
Makoto Endo ◽  
Tohru Tsuchiya ◽  
Kazuki Hamada ◽  
Shingo Kawamura ◽  
Kentaro Yano ◽  
...  
Keyword(s):  
Male Sterility ◽  
High Temperatures ◽  
Pollen Development ◽  
Rice Plants ◽  
Transcriptional Alterations

scholarly journals DFT calculation for the electronic properties and quantum capacitance of pure and doped Zr2CO2 as electrode of supercapacitors

2021 ◽  
Author(s):  
Shuo Xu ◽  
Shi-Jie Wang ◽  
Li Xiao-Hong ◽  
Hong-Ling Cui
Keyword(s):  
Electronic Properties ◽  
Electrode Materials ◽  
Chemical Properties ◽  
Effect Of Temperature ◽  
Quantum Capacitance ◽  
Substitutional Site ◽  
Level Shifts ◽  
Dirac Distribution ◽  
Increasing Temperature ◽  
Physical And Chemical

Defect and doping are effective methods to modulate the physical and chemical properties of materials. In this report, we investigated the structural stability, electronic properties and quantum capacitance (Cdiff) of Zr2CO2 by changing the dopants of Si, Ge, Sn, N, B, S and F in the substitutional site. The doping of F, N, and S atoms makes the system undergo the semiconductor-to-conductor transition, while the doping of Si, Ge, and Sn maintains the semiconductor characteristics. The Cdiff of the doped systems are further explored. The B-doped system can be used as cathode materials, while the systems doped by S, F, N, Sn atoms are promising anode materials of asymmetric supercapacitors, especially for the S-doped system. The improved Cdiff mainly originates from Fermi-level shifts and Fermi-Dirac distribution by the introduction of the dopant. The effect of temperature on Cdiff is further explored. The result indicates that the maximum Cdiff of the studied systems gradually decreases with the increasing temperature. Our investigation can provide useful theoretical basis for designing and developing the ideal electrode materials for supercapacitors.

scholarly journals Identification and Verification of Genes Related to Pollen Development and Male Sterility Induced by High Temperature in Thermo-sensitive Genic Male Sterile Wheat Line YanZhan 4110S

2020 ◽  
Author(s):  
Xuetong Yang ◽  
Jiali Ye ◽  
Fuqiang Niu ◽  
Yi Feng ◽  
Xiyue Song
Keyword(s):  
Gene Silencing ◽  
Male Sterility ◽  
Mosaic Virus ◽  
Pollen Development ◽  
Bioinformatics Analysis ◽  
Virus Induced Gene Silencing ◽  
Wheat Line ◽  
Pollen Abortion ◽  
Hub Genes ◽  
Genic Male Sterility

Abstract Background: Environment-sensitive genic male sterility is of vital importance to hybrid vigor in crop production and breeding, therefore, it is meaningful to identify and study the function of the genes related to pollen development and male sterility, which still not fully understanding currently. In this study, Yanzhan 4110S, a new thermo-sensitive genic male sterility (TGMS) wheat line, and its near isogenic line Yanzhan 4110 were carried out cytological features observation, bioinformatics analysis to investgate the abortion state and identified the genes involved in pollen development which have fertility regulation function. Barely stripe mosaic virus-induced gene silencing was used to verify the genes function.Results: Cytological analysis showed pollen abortion event of Yanzhan 4110S occur at the later uninucleate stage (Lun) under higher temperature induction (day/night temperatures of 22 °C/20 °C), when the anthers were collected and assessed for transcriptomic profiling through high-throughput sequencing. We then in-depth analyzed the differentially expressed genes (DEGs) by Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, the results showed that the occurrence of Yanzhan 4110S male-sterility most likely related to metabolic pathway, including phenylpropanoid biosynthesis in the biosynthesis of other secondary metabolites, starch and sucrose metabolism in carbohydrate metabolism, carbon fixation in photosynthetic organisms as well as carbon metabolism in energy metabolism. The weighted gene co-expression network analysis in the transcriptome profiles further identified some hub genes, where the key genes involved in those pathways were intersection between the unique DEGs of Yanzhan 4110S in anther and hub genes, totally 228 genes, which were highly related to pollen development including TaMut11 and TaSF3. Moreover, further verification through barely stripe mosaic virus-induced gene silencing elucidated that the silencing of TaMut11 and TaSF3 caused pollen abortion, finally resulting in the declination of fertility. So, the genes TaMut11 and TaSF3 are related to fertility conversion of Yanzhan 4110S.Conclusion: Through comparative transcriptome bioinformatics analysis, the genes TaMut11 and TaSF3 associated with pollen development and male sterility induced by high temperature were identified in Yanzhan 4110S, and verificated by barely stripe mosaic virus-induced gene silencing. These findings provided researching the abortive mechanism in environment-sensitive genic male sterility wheat.

scholarly journals Effects of the Temperature and the pH on the Main Protease of SARS-CoV-2: A Molecular Dynamics Simulation Study

2021 ◽  
Vol 12 (6) ◽  
pp. 7239-7248
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Root Mean Square ◽  
Dynamics Simulation ◽  
Effect Of Temperature ◽  
Water Molecules ◽  
Mean Square ◽  
Main Protease ◽  
Decreasing Ph ◽  
Increasing Temperature

The novel coronavirus, recognized as COVID-19, is the cause of an infection outbreak in December 2019. The effect of temperature and pH changes on the main protease of SARS-CoV-2 were investigated using all-atom molecular dynamics simulation. The obtained results from the root mean square deviation (RMSD) and root mean square fluctuations (RMSF) analyses showed that at a constant temperature of 25℃ and pH=5, the conformational change of the main protease is more significant than that of pH=6 and 7. Also, by increasing temperature from 25℃ to 55℃ at constant pH=7, a remarkable change in protein structure was observed. The radial probability of water molecules around the main protease was decreased by increasing temperature and decreasing pH. The weakening of the binding energy between the main protease and water molecules due to the increasing temperature and decreasing pH has reduced the number of hydrogen bonds between the main protease and water molecules. Finding conditions that alter the conformation of the main protease could be fundamental because this change could affect the virus’s functionality and its ability to impose illness.

scholarly journals Partial purification and properties of the two common inherited forms of human erythrocyte adenylate kinase

1972 ◽  
Vol 130 (3) ◽  
pp. 797-803 ◽  
Author(s):  
C. Brownson ◽  
N. Spencer
Keyword(s):  
Adenylate Kinase ◽  
Effect Of Temperature ◽  
Partial Purification ◽  
Heat Denaturation ◽  
Gel Chromatography ◽  
Molecular Weights ◽  
Purification And Properties ◽  
Increasing Temperature

1. The partial purification of adenylate kinase, types 1 and 2, from human erythrocytes is described. 2. Gel chromatography of both forms of the enzyme gave estimates of the molecular weights in the range 20000–23000. 3. Studies on crude haemolysates at various pH values indicated that the type 2 enzyme was less stable than the type 1. Heat denaturation studies on the partially purified enzymes confirmed these findings. 4. Measurements of rates of inhibition by iodoacetate and iodoacetamide showed that the type 2 enzyme reacts more readily than the type 1 enzyme with both reagents. 5. The effect of temperature on the initial velocity of ADP formation was measured at a single concentration of both AMP and MgATP2-. The two forms of the enzyme responded differently to increasing temperature.

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