scholarly journals Role of gibberellins and cytokinins in regulation of germination during development and ripening of Triticale caryopses

2014 ◽  
Vol 53 (2) ◽  
pp. 257-270 ◽  
Author(s):  
Stanisław Weidner
Keyword(s):  
Abscisic Acid ◽  
Gibberellic Acid ◽  
Significant Influence ◽  
Cell Elongation ◽  
Initial Period ◽  
Triticale Caryopses ◽  
Developmental Phases ◽  
Premature Germination ◽  
Stimulation Of

The germination of caryopses of M-T3 <em>Triticale</em> generation, which were freshly harvested in different growth and developmental phases has been studied. A significant influence of the abscisic acid (ABA) accumulation on the increment of number of germinating caryopses has been found. Already in the first phase af the embryogenesis considerable stimulating effects of kinetin and gibberellin-A<sub>3</sub> (GA<sub>3</sub>) on the germination of embryos which were isolated from freshly collected grains have been shown. When both stimulators were used together marked synergetic reaction occurred. It has been also determined that in the initial period of embryogensis premature germination occurs, to a higher extent, under the action of cytokinins than! Whether in the further phases of the caryopse development, when embryo develop mainly through the cell elongation, mostly gibberellins seem to be responsible for the activation of germination processes. The more mature were seeds the quicker germinated whole caryopses and embryos isolated from them at different ripeness, after 3-month storage. The highest stimulation of germination by phytohormones has been found for the most mature caryopses. The action of gibberellic acid has been particulary strong.

scholarly journals The role of zeatin and gibberellic acid in breaking of the abscisic acid-induced dormancy in Triticale caryopses

2014 ◽  
Vol 53 (3) ◽  
pp. 339-351
Author(s):  
Stanisław Weidner ◽  
Włodzimierz Makowski ◽  
Eugeniusz Sójka ◽  
Andrzej Rejowski
Keyword(s):  
Abscisic Acid ◽  
Ribosomal Proteins ◽  
Protein Biosynthesis ◽  
Initial Period ◽  
Uridine Incorporation ◽  
Triticale Caryopses ◽  
Lower Effect ◽  
Twofold Decrease ◽  
Excised Embryos

The investigations were conducted on the germinating embryos and the whole caryopses of <em>Triticale</em>. During preimbibition and 24 hours germination caryopses were treated with abscisic acid (ABA), which produced 63% inhibition of embryo growth. Gibberellin-A<sub>3</sub> (GA<sub>3</sub>) reversed the ABA effect in 18%, while zeatin in 22%. The clear synergic reaction was observed (36%) when both stimulators acted together. There was no significant effect of ABA, ABA and GA<sub>3</sub>, as well as ABA and zeatin on the synthesis of polyribosomal RNA in the initial period of germination of excised embryos. However, during 24 hours germination of whole caryopses ABA caused a twofold decrease in <sup>3</sup>H-uridine incorporation into the total fraction of embryonic ribosomes. While the incorporation of <sup>14</sup>C-aminoacid mixture into ribosomal proteins was even three-fold lower. Effect of GA<sub>3</sub> and zeatin on breaking of the ABA-induced "dormancy" was studied. It was confirmed that the higher polyribosome contribution to the sum total of ribosomes the more intensive synthesis of ribosomal proteins. No higher <sup>3</sup>H-uridine incorporation into polyribosomal fraction was observed. From the results it may be inferred that in the initial period of germination of <em>Triticale</em> caryopses regulation of protein biosynthesis occurs rather at the translation than transcription level.

scholarly journals Participation of the Tightly-Bound (Putative Cytoskeleton-Bound) Polysomes in Translation during Germination of Dormant and Non-Dormant Cereal Caryopses

2000 ◽  
Vol 55 (1-2) ◽  
pp. 23-29 ◽  
Author(s):  
Stanisław Weidner ◽  
Dorota Łukaszewicz ◽  
Ryszard Amarowicz
Keyword(s):  
Amino Acids ◽  
Abscisic Acid ◽  
Significant Role ◽  
Metabolic Activity ◽  
Triticale Caryopses ◽  
Membrane Bound ◽  
Polypeptide Chains ◽  
High Metabolic Activity

Abstract Research was done on dormant and non-dorm ant barley cv. Ars caryopses and triticale cv. Grado caryopses treated and non-treated with abscisic acid (ABA). During germination higher participation of populations of so-called tightly-bound polysom es (TBP) in embryos of dormant barley caryopses was observed, as well as their high metabolic activity. In embryos of triticale caryopses of which dormancy was imposed in an artificial way by ABA (100 μM), the strongest incorporation of 14C -amino acids into nascent polypeptide chains in vivo was found in population of TBP, as well as the highest participation among three of the studied fractions (free polysomes, membrane-bound polysom es and tightly-bound polysomes). These results may indicate the significant role of TBP (putative cytoskeleton-bound polysomes - CBP) in maintaining dormancy during imbibition of cereal caryopses.

Stomatal opening: the role of abscisic acid

1971 ◽  
Vol 49 (4) ◽  
pp. 583-585 ◽  
Author(s):  
Roger F. Horton
Keyword(s):  
Abscisic Acid ◽  
Gibberellic Acid ◽  
Vicia Faba ◽  
Guard Cells ◽  
Stomatal Opening ◽  
Water Potentials ◽  
Intact Leaves

Abscisic acid inhibits stomatal opening in isolated abaxial epidermal strips of Vicia faba. Kinetin, benzyladenine, and gibberellic acid, which can enhance stomatal apertures in intact leaves, are ineffective on isolated epidermal strips. Abscisic acid appears to act directly on the guard cells, rather than by influencing water potentials throughout the leaf.

Stimulation of Ca(2+)-dependent exocytosis of the sperm acrosome by cAMP acting downstream of phospholipase A2

Reproduction ◽  
2000 ◽  
pp. 57-68 ◽  
Author(s):  
J Garde ◽  
ER Roldan
Keyword(s):  
Arachidonic Acid ◽  
Phospholipase A2 ◽  
Phospholipase C ◽  
Phosphodiesterase Inhibitors ◽  
Dibutyryl Camp ◽  
Camp Phosphodiesterase ◽  
Ram Sperm ◽  
Camp Formation ◽  
Stimulation Of

Spermatozoa undergo exocytosis in response to agonists that induce Ca2+ influx and, in turn, activation of phosphoinositidase C, phospholipase C, phospholipase A2, and cAMP formation. Since the role of cAMP downstream of Ca2+ influx is unknown, this study investigated whether cAMP modulates phospholipase C or phospholipase A2 using a ram sperm model stimulated with A23187 and Ca2+. Exposure to dibutyryl-cAMP, phosphodiesterase inhibitors or forskolin resulted in enhancement of exocytosis. However, the effect was not due to stimulation of phospholipase C or phospholipase A2: in spermatozoa prelabelled with [3H]palmitic acid or [14C]arachidonic acid, these reagents did not enhance [3H]diacylglycerol formation or [14C]arachidonic acid release. Spermatozoa were treated with the phospholipase A2 inhibitor aristolochic acid, and dibutyryl-cAMP to test whether cAMP acts downstream of phospholipase A2. Under these conditions, exocytosis did not occur in response to A23187 and Ca2+. However, inclusion of dibutyryl-cAMP and the phospholipase A2 metabolite lysophosphatidylcholine did result in exocytosis (at an extent similar to that seen when cells were treated with A23187/Ca2+ and without the inhibitor). Inclusion of lysophosphatidylcholine alone, without dibutyryl-cAMP, enhanced exocytosis to a lesser extent, demonstrating that cAMP requires a phospholipase A2 metabolite to stimulate the final stages of exocytosis. These results indicate that cAMP may act downstream of phospholipase A2, exerting a regulatory role in the exocytosis triggered by physiological agonists.

Peran kepemilikan institusional, perencanaan pajak dan dewan komisaris asing terhadap nilai perusahaan

2019 ◽  
Vol 8 (2) ◽  
Author(s):  
Anita Ade Rahma ◽  
Lisa Nabawi ◽  
Ronni Andri Wijaya
Keyword(s):  
Significant Influence ◽  
Firm Value ◽  
Stock Exchange ◽  
Investment Decisions ◽  
Total Sample ◽  
Tax Planning ◽  
Purposive Sampling ◽  
Institutional Leadership ◽  
Company Value

The purpose of this study is to analyze the role of institutional leadership, tax planning and foreign board of commissioners on firm value. The population in this study were 615 companies listed on the Indonesia Stock Exchange in 2015-2017. The sample was chosen using purposive sampling to get a total sample of 325 companies with a total of 975 observations of company data. The results of this study indicate that institutional leadership and tax planning have no role in increasing company value. While the foreign board of commissioners showed a significant influence on the value of the company. This proves that there is a need for diversity in the structure of the board that can trigger an increase in the value of the company. In addition, the presence of a foreign board is needed for the progress of the companyKeywords: Investment decisions; funding decisions; dividend policy; company value

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