scholarly journals Changes in auxin level in the course of growth of a sunflower crown-gall suspension culture

2014 ◽  
Vol 52 (3-4) ◽  
pp. 285-294 ◽  
Author(s):  
Zofia Chirek
Keyword(s):  
Suspension Culture ◽  
Crown Gall ◽  
Culture Medium ◽  
Cell Mass ◽  
Maximum Growth ◽  
Maximal Growth ◽  
Auxin Level ◽  
Culture Cycle ◽  
Crown Gall Tumour ◽  
Further Development

The auxin level in the cell mass and culture medium was determined by means of the <em>Avena</em> straight caleoptile test in various periods of the suspension culture cycle of the sunflower crown-gall tumour. The investigations were performed in the course of the zero passage (PO) and first one (Pl), differing in their time of duration of maximum growth and its intensity. In both passages the intra- and extra-cellular auxin levels reach values of the same order. At the beginning of the maximal growth phase the activity corresponding to IAA in the cells prevails over that of the other auxin-like compounds. This disproportion diminishes with further development of the culture, and with the beginning of the stationary phase the cellular IAA level is lower than that of the remaining auxin-like compounds. The short phase of maximal growth (PO) occurs with an auxin level decreasing in the cell mass and increasing in the medium, and towards the end of the cycle these levels become equal. During the long phase of maximal growth (Pl) the total amount of auxins in the cells increases and is 2-3 times higher than in the medium, whereas IAA in the cells remains at a constant level. These results suggest that the participation of IAA in the intracellular pool of auxin-like substances is decisive for the mitotic activity of the cells and maintenance of growth in the culture.

scholarly journals Dynamics of indole-3-acetic acid oxidase activity in suspension culture of sunflower crown-gall

2014 ◽  
Vol 53 (1) ◽  
pp. 67-75 ◽  
Author(s):  
Zofia Chirek
Keyword(s):  
Suspension Culture ◽  
Crown Gall ◽  
Oxidase Activity ◽  
Middle Part ◽  
Acid Oxidase ◽  
Iaa Oxidase ◽  
Auxin Level ◽  
Feedback Type ◽  
Indole 3 Acetic Acid ◽  
Intensive Growth

IAA oxidase activity was determined in several growth phases of a suspension culture of sunflower crown-gall. During the short phase of intensive growth (zero passage - PO) a negative correlation was noted between enzymatic activity and the rate of growth. IAA oxidase activity increased to a certain level is not a factor limiting cell division. For protraction of the phase of intensive growth (first passage - P1), however, a decrease in the activity of this enzyme seems indispensable. IAA oxidase activity in the tested culture is under the control of inhibitors present in the cells and medium. High enzyme inhibition was observed in PO cells during the phase, of intensive growth and in P1 at the beginning and in the middle part of this phase. These results suggest' that the -auxin level determined in earlier studies in sunflower crown-gall culture is controlled by the IAA oxidase set. During the long phase of intensive growth (P1) this control is of negative feedback type.

scholarly journals Polyamine Metabolism in Scots Pine Embryogenic Cells under Potassium Deficiency

Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1244
Author(s):  
Riina Muilu-Mäkelä ◽  
Jaana Vuosku ◽  
Hely Häggman ◽  
Tytti Sarjala
Keyword(s):  
Scots Pine ◽  
Culture Medium ◽  
Developmental Regulation ◽  
Cell Mass ◽  
Arginine Decarboxylase ◽  
Protective Role ◽  
Potassium Deficiency ◽  
Polyamine Metabolism ◽  
Embryogenic Cells ◽  
Embryogenic Cell

Polyamines (PA) have a protective role in maintaining growth and development in Scots pine during abiotic stresses. In the present study, a controlled liquid Scots pine embryogenic cell culture was used for studying the responses of PA metabolism related to potassium deficiency. The transcription level regulation of PA metabolism led to the accumulation of putrescine (Put). Arginine decarboxylase (ADC) had an increased expression trend under potassium deficiency, whereas spermidine synthase (SPDS) expression decreased. Generally, free spermidine (Spd) and spermine (Spm)/ thermospermine (t-Spm) contents were kept relatively stable, mostly by the downregulation of polyamine oxidase (PAO) expression. The low potassium contents in the culture medium decreased the potassium content of the cells, which inhibited cell mass growth, but did not affect cell viability. The reduced growth was probably caused by repressed metabolic activity and cell division, whereas there were no signs of H2O2-induced oxidative stress or increased cell death. The low intracellular content of K+ decreased the content of Na+. The decrease in the pH of the culture medium indicated that H+ ions were pumped out of the cells. Altogether, our findings emphasize the specific role(s) of Put under potassium deficiency and strict developmental regulation of PA metabolism in Scots pine.

Mesophilic mutants of an obligate psychrophile, Micrococcus cryophilus

1969 ◽  
Vol 15 (10) ◽  
pp. 1145-1150 ◽  
Author(s):  
P-C. Tai ◽  
H. Jackson
Keyword(s):  
Growth Temperature ◽  
Metabolic Pathways ◽  
Thermal Denaturation ◽  
Deoxyribonucleic Acid ◽  
Elevated Temperatures ◽  
Maximum Growth ◽  
Maximal Growth ◽  
Denaturation Temperature ◽  
Maximum Growth Temperature ◽  
Thermal Denaturation Temperature

Several mutants with elevated maximal growth temperature (MGT) were developed from an obligate psychrophile, Micrococcus cryophilus ATCC 15174, by ultraviolet irradiation. Two of the mutants, T8 and M19, have the most similar characteristics to those of their parent. The mutants lost the ability to grow well at 0 °C and showed changes in metabolic pathways while acquiring the ability to grow at elevated temperatures. Heat resistance and deoxyribonucleic acid thermal denaturation temperature were shown to be unrelated to maximum growth temperature. The significance of the mutants is discussed.

Growth Profile of Crown Gall Cells of Tobacco in Suspension Culture

1975 ◽  
Vol 39 (2) ◽  
pp. 485-490
Author(s):  
Takashi Matsumoto ◽  
Keiko Okunishi ◽  
Koh Nishida ◽  
Masao Noguchi
Keyword(s):  
Suspension Culture ◽  
Crown Gall ◽  
Growth Profile

Transmission of nopaline crown gall tumour markers through meiosis in regenerated whole plants of Bidens alba

1984 ◽  
Vol 62 (3) ◽  
pp. 408-413 ◽  
Author(s):  
Robert A. Norton ◽  
G. H. N. Towers
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Apical Dominance ◽  
Crown Gall ◽  
Morphological Traits ◽  
Tumour Marker ◽  
Mendelian Inheritance ◽  
Fourth Generation ◽  
Crown Gall Tumour ◽  
Whole Plants ◽  
Auxin Autotrophy

Results show the feasibility of regenerating rooting Bidens alba plants from nopaline-type crown galls incited by Agrobacterium tumefaciens containing pTi-T37. Transmission of the tumour marker nopaline synthesis is demonstrated into the fourth generation but decreases in level of expression or loss of the trait occurs. Nopaline synthesis and auxin autotrophy, as markers, can also be differentially lost, making it difficult to demonstrate Mendelian inheritance. Formation of octopine-type tumours on nopaline positive plants occurs in a high percentage of inoculations. Transformed plants show several morphological traits which distinguish them from normal plants: they are smaller, have decreased apical dominance, show hypertrophy of the hypocotyl region, lower nodes, and petiole bases, and frequently form an extra spur of tissue in ray flowers.

scholarly journals Cell lineage allocation in equine blastocysts produced in vitro under varying glucose concentrations

Reproduction ◽  
2015 ◽  
Vol 150 (1) ◽  
pp. 31-41 ◽  
Author(s):  
Young-Ho Choi ◽  
Pablo Ross ◽  
Isabel C Velez ◽  
B Macías-García ◽  
Fernando L Riera ◽  
...  
Keyword(s):  
High Glucose ◽  
Culture Medium ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Cell Lineage ◽  
Primitive Endoderm ◽  
Blastocyst Development ◽  
Embryo Culture Medium ◽  
Effect Of Glucose

Equine embryos developin vitroin the presence of high glucose concentrations, but little is known about their requirements for development. We evaluated the effect of glucose concentrations in medium on blastocyst development after ICSI. In experiment 1, there were no significant differences in rates of blastocyst formation among embryos cultured in our standard medium (DMEM/F-12), which contained >16 mM glucose, and those cultured in a minimal-glucose embryo culture medium (<1 mM; Global medium, GB), with either 0 added glucose for the first 5 days, then 20 mM (0-20) or 20 mM for the entire culture period (20-20). In experiment 2, there were no significant differences in the rates of blastocyst development (31–46%) for embryos cultured in four glucose treatments in GB (0-10, 0-20, 5-10, or 5-20). Blastocysts were evaluated by immunofluorescence for lineage-specific markers. All cells stained positively forPOU5F1. An inner cluster of cells was identified that included presumptive primitive endoderm cells (GATA6-positive) and presumptive epiblast (EPI) cells. The 5-20 treatment resulted in a significantly lower number of presumptive EPI-lineage cells than the 0-20 treatment did.GATA6-positive cells appeared to be allocated to the primitive endoderm independent of the formation of an inner cell mass, as was previously hypothesized for equine embryos. These data demonstrate that equine blastocyst development is not dependent on high glucose concentrations during early culture; rather, environmental glucose may affect cell allocation. They also present the first analysis of cell lineage allocation inin vitro-fertilized equine blastocysts. These findings expand our understanding of the factors that affect embryo development in the horse.

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