Effet des noeuds sur la direction de croissance des bourgeons axillaires des stolons de Stachys silvatica

1980 ◽  
Vol 58 (4) ◽  
pp. 466-470 ◽  
Author(s):  
E. Pfirsch ◽  
Th. Makosso

The plagiogeotropic growth of axillary buds of the epigeous autonomous stolon of Stachys silvatica is governed by multiple correlations inside this stolon. The horizontal growth of axillary buds on single node cultures depends on the action of a stolonisation substance, and on the presence of leaves on this node; leaves can be replaced with abscisic acid. The growth of the isolated bud, cultured in vitro, is always orthotropic, even though a stolonisation substance and abscisic acid are added to the culture medium. It thus appears that the node is the decisive element for horizontal growth.

Biomolecules ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1231
Author(s):  
Tatiana N. Arkhipova ◽  
Nina V. Evseeva ◽  
Oksana V. Tkachenko ◽  
Gennady L. Burygin ◽  
Lidiya B. Vysotskaya ◽  
...  

Water deficits inhibit plant growth and decrease crop productivity. Remedies are needed to counter this increasingly urgent problem in practical farming. One possible approach is to utilize rhizobacteria known to increase plant resistance to abiotic and other stresses. We therefore studied the effects of inoculating the culture medium of potato microplants grown in vitro with Azospirillum brasilense Sp245 or Ochrobactrum cytisi IPA7.2. Growth and hormone content of the plants were evaluated under stress-free conditions and under a water deficit imposed with polyethylene glycol (PEG 6000). Inoculation with either bacterium promoted the growth in terms of leaf mass accumulation. The effects were associated with increased concentrations of auxin and cytokinin hormones in the leaves and stems and with suppression of an increase in the leaf abscisic acid that PEG treatment otherwise promoted in the potato microplants. O. cytisi IPA7.2 had a greater growth-stimulating effect than A. brasilense Sp245 on stressed plants, while A. brasilense Sp245 was more effective in unstressed plants. The effects were likely to be the result of changes to the plant’s hormonal balance brought about by the bacteria.


Author(s):  
M. A. Sundyreva ◽  
A. N. Rebrov ◽  
A. E. Mishko ◽  
E. O. Lutsky

An increase in sucrose in the medium increased the content of pigments, gene expression of the photosynthetic apparatus, growth processes, and H2O2, but decreased the quantum yield of photosynthesis. With a change in the sucrose content in the medium, the expression of ABA1 increased most intensively. 30 g/l of sucrose in the medium inhibited the expression of genes involved in the formation of ABA.


1983 ◽  
Vol 61 (9) ◽  
pp. 2343-2348
Author(s):  
M. W. Zink

The effect of abscisic acid on the levels and the developmental patterns of the two acid phosphatases in the culture medium, in the soluble fraction, and in the particulate fraction of Ipomoea sp. (morning glory) cultured in vitro depends upon the phosphate status of the cells. Under conditions of mineral stress or phosphate deprivation the enzymes are derepressed and this derepression is suppressed by abscisic acid. No inhibition of the synthesis of the phosphatases by the hormone occurs when the cells are grown under conditions of high phosphate. The significance of the abscisic effect on the derepression of the acid phosphatases is discussed.


Author(s):  
Candra Catur Nugroho ◽  
Nurul Khumaida ◽  
Dan Sintho Wahyuning Ardie

ABSTRACT<br /><br />The continuous supply of true-to-type seedling through in vitro technique is very important for cassava (Manihot esculenta Crantz.) as the demand for seedlings is increasing. The research consisted of two experiments and they were conducted from February 2013 to February 2014. The first experiment was in vitro shoot multiplication to evaluate the effect of culture medium and single node position on growth and shoot multiplication of cassava Jame-jame genotype. This experiment was arranged in a randomized complete block design with two factors and four replications. The first factor was culture medium (MS0 and MSB3) and the second factor was single node positions used as explant (basal, middle, and top section of the stem). The result showed that middle section of the stem cultured on MS0 medium had the highest shoot height, number of leaves, and number of nodes. The second experiment was the acclimatization to evaluate the effect of culture period on the success of the acclimatization. This experiment was arranged in a completely randomized design with culture period prior to acclimatization as treatment. The results showed that seedlings from period of 12 and 24 weeks after culture showed higher survival rates (80%) than seedling from period of 36 and 48 weeks after culture (50 and 40%). Culture period prior to acclimatization had no significant effect on plant height and number of leaves.<br /><br />Keywords: BAP, culture period, single node position, shoot multiplication


1991 ◽  
Vol 125 (3) ◽  
pp. 280-285 ◽  
Author(s):  
J. Alan Talbot ◽  
Ann Lambert ◽  
Robert Mitchell ◽  
Marek Grabinski ◽  
David C. Anderson ◽  
...  

Abstract We have investigated the role of Ca2+ in the control of FSH-induced estradiol secretion by Sertoli cells isolated from 8-10 days old rats. Exogenous Ca2+ (4-8 mmol/1) inhibited FSH-stimulated E2 secretion such that, with 8 mmol/l Ca2+ and FSH (8 IU/l) E2 secretion decreased from 2091±322 to 1480±84 pmol/l (p<0.002), whilst chelation of Ca2+ in the culture medium with EGTA (3 mmol/l) increased E2 secretion from 360±45 to 1242±133 pmol/l) in the absence of FSH. Further, EGTA (3 mmol/l) markedly potentiated FSH (8 IU/l), forskolin (1 μmol/l) and dibutyryl cAMP (1 mmol/l)-stimulated E2 secretion. Addition of the Ca2+ ionophores, ionomycin (2-5 μmol/l) and A23187 (2 μmol/l), inhibited FSH (8 IU/l)-stimulated E2 secretion by >80%. The effect of ionomycin was totally reversible, whereas that of A23187 was irreversible. Ionomycin (5 μmol/l) had no effect on EGTA-induced E2 secretion in the absence of FSH, but reduced EGTA-provoked E2 secretion by 59% in the presence of FSH (8 IU/l). Similarly, forskolin- and dibutyryl cAMP-provoked E2 production was inhibited 46-50% by ionomycin (5 μmol/l). We conclude that FSH-induced E2 secretion from immature rat Sertoli cells is modulated by intra- and extracellular Ca2+.


Reproduction ◽  
2000 ◽  
pp. 391-396 ◽  
Author(s):  
AH Duittoz ◽  
M Batailler

The aim of this study was to investigate the development of pulsatile GnRH secretion by GnRH neurones in primary cultures of olfactory placodes from ovine embryos. Culture medium was collected every 10 min for 8 h to detect pulsatile secretion. In the first experiment, pulsatile secretion was studied in two different sets of cultures after 17 and 24 days in vitro. In the second experiment, a set of cultures was tested after 10, 17 and 24 days in vitro to investigate the development of pulsatile GnRH secretion in each individual culture. This study demonstrated that (i) primary cultures of GnRH neurones from olfactory explants secreted GnRH in a pulsatile manner and that the frequency and mean interpulse duration were similar to those reported in castrated ewes, and (ii) pulsatile secretion was not present at the beginning of the culture but was observed between 17 and 24 days in vitro, indicating the maturation of individual neurones and the development of their synchronization.


Author(s):  
С.В. Калиш ◽  
С.В. Лямина ◽  
А.А. Раецкая ◽  
И.Ю. Малышев

Цель исследования. Репрограммирование М1 фенотипа макрофагов с ингибированными факторами транскрипции М2 фенотипа STAT3, STAТ6 и SMAD и оценка их влияния на развитие карциномы Эрлиха (КЭ) in vitro и in vivo. Методика. Рост опухоли иницировали in vitro путем добавления клеток КЭ в среду культивирования RPMI-1640 и in vivo путем внутрибрюшинной инъекции клеток КЭ мышам. Результаты. Установлено, что M1макрофаги и in vitro, и in vivo оказывают выраженный противоопухолевый эффект, который превосходит антиопухолевые эффекты М1, M1, M1 макрофагов и цисплатина. Заключение. М1 макрофаги с ингибированными STAT3, STAT6 и/или SMAD3 эффективно ограничивают рост опухоли. Полученные данные обосновывают разработку новой технологии противоопухолевой клеточной терапии. Objective. Reprogramming of M1 macrophage phenotype with inhibited M2 phenotype transcription factors, such as STAT3, STAT6 and SMAD and assess their impact on the development of Ehrlich carcinoma (EC) in vitro and in vivo . Methods. Tumor growth in vitro was initiated by addition of EC cells in RPMI-1640 culture medium and in vivo by intraperitoneal of EC cell injection into mice. Results. It was found that M1 macrophages have a pronounced anti-tumor effect in vitro , and in vivo , which was greater than anti-tumor effects of M1, M1, M1 macrophages and cisplatin. Conclusion. M1 macrophages with inhibited STAT3, STAT6 and/or SMAD3 effectively restrict tumor growth. The findings justify the development of new anti-tumor cell therapy technology.


Agrologia ◽  
2018 ◽  
Vol 1 (1) ◽  
Author(s):  
S. Tuhuteru ◽  
Meity L Hehanussa ◽  
Simon H.T Raharjo

Dendrobium anosmum is one of natural orchids in Indonesia. Optimization of medium composition for orchid propagation through in vitro culture is necessary to enhance propagule multiplication capabilities and quality. This study was aimed to study the influence of concentration of coconut water in culture medium on in vitro growth and development of D. anosmum orchid species and to determine the optimal coconut water concentration in culture media.  The experiment were arranged in a Completely Randomized Design with four treatments and eight replications. The treatments consisted of the addition of coconut water with concentrations: 0 ml•l -1 (control), 50 ml•l-1, 100 ml•l-1 and 150 ml•l-1. The results showed that addition of coconut water in culture medium gave different effect on shoot growth and multiplication of D. anosmum orchids.  Coconut water concentration of 100 ml•l-1 was the best concentration for growth and multiplication of D. anosmum orchids, based on both shoots and roots growth, plantlet height and wet weight.


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