Growth Of Callus Tissue Research Articles

Response of wheat genotypes to excess boron estimated by in vitro culture

The objective of this study was to evaluate boron tolerance of wheat genotypes using mature embryo culture. The analysis involved 79 recombinant inbred lines of the International Triticeae Mapping Initiative (ITMI) population and three Serbian varieties with known boron (B) tolerance (Pobeda - sensitive S, Balerina-medium tolerant MT, and Nevesinjka - tolerant T). The evaluation was performed on a modified MS medium to which 15 mM of boric acid was added. The control medium contained no excess B. Callus fresh weight (CFW) and reduction of fresh callus weight (RFCW) were determined after one month of cultivation. ANOVA has shown highly significant effect of genotype, the media, and their interaction to callus tissue growth and also significant genotypic effect on RFCW. Majority of genotypes (39) had sensitive reaction to excess boron, twenty-three were medium tolerant, while four of them were tolerant. The obtained results can be potentially used for mapping QTLs associated with tolerance to excess B in wheat breeding program.

AS ANATOMICAL FEATURES OF THE XYLEM COULD INFLUENCE WOUND HEALING PROCESS IN TREES?

Since trees are continually at risk of damage from animals and adverse environmental conditions, their survival depends on wound healing capacity. Common physiological responses to injury are cell proliferation, regeneration of the vascular tissue and the formation of compounds to protect cells near the wound. The wood anatomy is important for understanding the mechanisms of wound healing, and hence tree survival. We studied twelve tropical tree species to understand how some wood characteristics contribute to the wound healing process. We made the quantitative analysis of wood characteristics and evaluated the rate of wound healing two years after the collection of samples. Species with a large amount of axial parenchyma, presented the highest wound healing rate, proving that axial parenchyma cell supply material for greater cell proliferation, acting to close the wound much faster. Species that have axial parenchyma and produce a network between vessels and rays through living tissue, recover and provide passage of hormones that stimulate cell division of tissue near the wound, promoting growth of callus tissue all around the wound area, accelerating wound closure. On the other hand, the absence of axial parenchyma hinders such recovery by disabling affected regions; both above and below the injury, from producing sufficient wound healing tissue. The presence of longer fibers is an indicative of a larger amount of gibberellin that is involved in cell division during wound healing; therefore, species with longer fibers had faster wound healing.

A limping dinosaur in the Late Jurassic: Pathologies in the pes of the neornithischian Othnielosaurus consors from the Morrison Formation (Upper Jurassic, USA)

ABSTRACT The study of palaeopathology provides valuable information about injury and behaviour in extinct organisms. Appendicular pathologies are interesting as they directly affect mobility and therefore the ability of an animal to survive. Here, the injuries recorded in the left pes of the neornithischian Othnielosaurus consors are described. The implications of these injuries in its behaviour are also discussed. Othnielosaurus shows pathological features in all its pes digits, with three types of pathologies have been identified: calcium pyrophosphate deposition disease (CPPD), and pilon and impact fractures. Calcium pyrophosphate deposition disease is visible on the articular surface of phalange II-3 as a small osseous plaque. A pilon fracture is evidenced by the growth of callus tissue on the shaft of the phalange I-1 and demonstrates healing before death. The impact fractures are identified as a focal subsidence on the articular surfaces of phalanges III-1 and IV-4, which are partially healed. Perhaps the suite of palaeopathologies encountered would generate pain and discomfort when walking, which probably resulted in a limp that would have impacted on its lifestyle. Finally, the fact that the fractures are in different stages of healing would suggest that impact fractures could have contributed to the death of the individual.

Possible replacement of cytokinins and auxins in culture in vitro

Aim. To perform an analysis of the effectiveness of our proposed modification of the classical MS medium in which auxin and cytokinin are replaced by derivatives of the class of tetrahydrothio-fendioxide and pyridine. Methods. In this study, the work with cell culture in vitro, in particular aseptic sprouting of seeds, microclonal reproduction, callusogenesis and initiation of various types of morphogenesis was carried out according to known techniques. Two varieties of potatoes (Slovyanka, Lugovskaya) and two varieties of tomato (Lagidny, Bobrytsky) were used to induce somaclonal variability. Results. The ability of preparations of tetrahydrothiophenedioxide and pyridine derivatives to perform the function of auxins and cytokinins in the MS medium in the callusogenesis of Solanacea cultures in vitro was established. Conclusions. It has been shown that with the use of the new generation drug (tetrahydrothiophenedioxide-pyridine), as a substitute for auxin and cytokinin in the MS medium, the growth of callus tissue is even increased. The production of the pilot batch of this substitute proved to be much cheaper than synthesis or the purchase of phytohormones.
 Keywords: modification of MS medium, phytohormones substitute, tetrahydro-thiophenedioxide-pyridine, potato, tomato.

Physiological and biochemical effects of morphactin IT 3233 on callus and tumour tissues of Nicotiana tabacum L. cultured in vitro. I. Growth and nitrogen compounds content

A significant limitation of callus tissue growth was noted in <i>Nicotiana tabacum</i> L. cultured in vitro under the influence of morphactin IT 3233 applied in 10 - 40 mg/dm<sup>3</sup> concentrations. Growth inhibition was associated with an increase in dry mass content and the contribution of protein N to the nitrogen, pool. Tumour tissue of tobacco under the same conditions reacted weaker to morphactin. Growth limitation reached 25 per cent as compared with the control, dry mass and nitrogen compounds content showed only slight variations. It is supposed that the different sensitivity of both types of tissues to morphactin is connected with their different hormonal metabolism.

Physiological and biochemical effects of morphactin IT 3233 on callus and tumour tissues of Nicotiana tabacum L. cultured in vitro. II. Protein synthesis and respiratory activity

It was found that the inhibition of callus tissue growth in <i>Nicotiana tabacum</i> L. cultured <i>in vitro</i> by the application of morphactin IT 3233 is associated with a rise of the protein level in spite of a 50 per cent depression of its synthesis. Respiratory activity of these tissues is also lowered. Tumour tissues, on the other hand, show only light changes in the parameters studied. It would seem that morphactin depresses a metabolic activity in the callus tissues, and probably causes deposition of a, large quantity of metabolically inactive proteins.

The effect of benzene and its Chlorella vulgaris metabolites on the growth of tobacco tissue

The influence of benzene, phenol and catechol on the tobacco callus tissue (<i>Nicotiana tabacum</i> L. cv. Wisconsin No. 38) cultivated <i>in vitro</i> was studied. Although inhibition of callus tissue growth in relation to the control was observed in all variants, the benzene-induced inhibition was the most significant. When catechol and phenol were added to the cultivation medium together, callus tissue growth was similar to that of the control. The addition of catechol to the medium containing phenol presumably reduces the toxic effect of phenol on the callus tissue examined. Callus tissue growing in the presence of phenol, benzene and cathechol became senescent more rapidly than in the control. Moreover microscopic examination revealed significant changes in the callus structure.

Effect of Hypergravity and Phytohormones on Isoflavonoid Accumulation in Soybean (Glycine max. L.) Callus

The objective of this study was to explore the potential interaction between gravity and growth hormones on isoflavonoid accumulation. Soybean callus (Glycine max (L.) Merr. cv. ‘Acme’) was grown in the dark for 16 days at 22 °C in a growth medium supplemented with four different combinations of phytohormones and subjected to 4-g and 8-g forces simulated in a centrifuge and 1-g in an adjacent stationary control. Isoflavonoid aglycones and their glycoside concentrations (daidzein, genistein, daidzin, 6″-O-malonyl-7-O-glucosyl daidzein, genistin, 6″-O-malonyl-7-O-glucosyl genistein) were determined in the resulting tissues. Although gravity had no significant impact on callus growth, increasing gravity reduced isoflavonoid accumulation in three out of the four phytohormone-supplemented culture media. The ratio of the auxin naphthalene acetic acid (NAA) to the cytokinin benzylaminopurine (BAP) was found to have profound effect on both callus growth and isoflavonoid accumulation. The cytokinin BAP promoted callus tissue growth, but reduced callus isoflavonoid suggesting the isoflavonoid accumulation was not keeping pace with the cell growth in the elevated concentration of BAP. On the other hand, NAA had little or no effect on callus growth, but greatly enhanced isoflavonoid accumulation. Interactive effects of gravity and hormone on isoflavonoid accumulation were evident and its implication to the mechanism by which gravity exerts the effect on plant secondary metabolites is discussed.

The effect of mret treatment on human astrocyte cells post exposed to ionizing radiation of 2gy and 8 gy

The effect of mret treatment on human astrocyte cells post exposed to ionizing radiation of 2gy and 8 gy

1-MCP CAN PREVENT ETHYLENE-INDUCED DAMAGE TO FRUIT TREES DURING COLD STORAGE

At present, about 50% of the young fruit trees is stored for more than one month in cold rooms between lifting in the nursery and planting in spring in the orchard with a maximum storage duration of 5-6 months. Storage of fruit trees requires the absence of ethylene in the storage room, as this gaseous plant growth regulator may induce damage to the trees during storage, which eventually may lead to the death of branches or the whole trees after planting the tree in the orchard. In 2007 a series of experiments was carried out to find out the sensitivity of ‘Conference’ pear trees to ethylene. In addition, the possible use of 1-MCP treatment before storage of the pear trees was examined as a means to prevent ethylene-induced damage. Tree damage was monitored during and directly after storage as well as after planting the trees in the orchard in spring following the storage period in winter. Ethylene-induced symptoms are the discoloration and death of local areas of bark tissue, death of buds and the occurrence of local cracks in the bark followed by the growth of callus tissue. Ethylene-induced damage was observed only when trees were exposed to 5 mg/L ethylene for 1 month at a temperature of 4°C. No damage occurred in case trees were only exposed to this concentration for 1 week at 4°C or for up to 1 month when stored at a temperature of 0°C. Trees treated with 1-MCP before storage did not develop any damage when exposed to 5 mg/L ethylene for 1 month at 4°C, demonstrating that 1-MCP is also taken up by trees harvested after leaf drop. Sensitivity towards ethylene seemed to be dependent on the time of lifting of the trees in the nursery. A trend was observed that trees grubbed in January developed less symptoms after a month exposure to 5 mg/L ethylene at 4°C than trees given the same treatment but lifted in November or March. This suggests that fully dormant trees are less sensitive to ethylene than trees lifted in autumn or spring. Amelioration of the damage after planting the trees in the field was strongly dependent on the amount of damage occurred during storage. Trees with only a little damage recovered quite well, but those with more severe damage often did not recover. Branches or even the whole tree died as result of the damage symptoms developed during storage. Trees treated with 1-MCP before storage showed a normal development after planting in the orchard and were indistinguishable from the untreated control trees. Further research is needed to more accurately determine the concentration, duration and temperature during exposure at which ethylene becomes harmful to pear trees in storage in order to prevent damage and optimise the use of 1-MCP. INTRODUCTION In the Netherlands many growers prefer to plant young fruit trees in spring when soil and weather condition are usually better than those in the autumn or early winter. At present, about 50% of the young fruit trees planted in spring is stored in cold rooms for more than one month between the moment of lifting in the nursery and planting in spring, with a maximum storage duration of 5-6 months. Occasionally, this cold storage results in damage to the young fruit trees, especially in ‘Conference’ pear trees. Visible damage occurred as local areas of discoloured bark tissue, death buds, and local cracks in the bark Proc. XI IS on Plant Bioregulators in Fruit Production

The impact of zearalenone and thidiazuron on indirect plant regeneration of oilseed rape and wheat

The aim of the study was to test the synergistic activity of zearalenone and thidiazuron with commonly used regulators (6-benzylaminopurine, 2,4-dichlorophenoxyacetic acid) in callus tissue growth and the regeneration processes of winter oilseed rape and winter wheat. Oilseed rape callus was obtained from the upper fragments of seedling hypocotyls. Wheat callus tissue was obtained from immature embryos. Zearalenone, in combination with 6-benzylaminopurine, stimulated the regeneration of oilseed rape and, in combination with 2,4-dichlorophenoxyacetic acid, the regeneration of wheat. An additional application of thidiazuron to these media increased the percentage of shoot regeneration from callus in both species tested. Zearalenone is proposed as a new regulator in in vitro plant cultures for use in protocols of plant regeneration.

Production of lignans in callus culture of <i>Podophyllum hexandrum</i>

Purpose: Podophyllum hexandrum Royle, a source of highly valued podophyllotoxin has been subjected to heavy collection from the wild. The ever-increasing demand of podophyllum is mainly due to two semi synthetic derivatives of podophyllotoxin that is etoposide and teniposide, which are used in the treatment of various types of cancer. The anti cancer lignan derivative podophyllotoxin in Podophyllum hexandrum is biosynthesized at very low quantities in intact plant, so the biotechnological production of podophyllotoxin has been considered essential. Method: The aseptically germinated embryos of Podophyllum hexandrum were developed on solid nutrient agar slab. For the growth of callus culture, Murashigae and Skoog media (MS media)) with various concentrations of BAP, NAA and GA3 adjusted to pH 5.8 was used. Podophyllotoxin content in the alcoholic extract of calli and plant root was analysed by HPLC and HPTLC and was also compared with cultivated Podophllum hexandrum root extracts. Result: A fully defined MS medium supplemented with Naphthalene acetic acid and 6benzylaminopurine (BAP) were effective for both initiation and sustained growth of callus tissue. The relative proportion of callus was markedly influenced by presence of plant growth regulators. The amount of Podophyllotoxin obtained from callus was 0.78 and 0.79 percent as characterized by HPLC and HPTLC respectively. Conclusion: The study revealed that callus culture may be a fruitful tool for the production of Podophyllotoxin resin, an anticancer entity.

Flavones from Callus Tissue of Iris ensata

Flavonoids uncharacteristic of intact plants were isolated from callus tissue of Iris ensata and were identified as 5-hydroxy-4′-methoxyflavone, 5-hydroxy-3′-methoxyflavone, and 5-hydroxy-2′-methoxyflavone using PMR and mass spectrometry. It was proposed that the lack of growth of callus tissue after changing cultivation conditions was related to the inhibiting effect of these flavones on cell proliferation.

Specific Features of Cultivation of Iris ensata Thunb. Callus Tissue

A continuous callus culture was obtained from zygotic embryos of Japanese iris (Iris ensata Thunb.) on Murashige–Skoog medium supplemented with 2 mg/l α-naphthylacetic acid and 0.5 mg/l 6-benzylaminopurine (BAP). It was found that successful callusogenesis required isolated embryos at the wax stage of endosperm development. The optimal combination of phytohormones for the growth of callus tissue was 1 mg/l 2,4-dichlorophenoxyacetic acid and 0.5 mg/l BAP. The pigment composition of I. ensata callus tissue was studied. It was demonstrated that subcultivated callus tissue contained red pigments of flavonoid nature. Under stress cultivation conditions, yellow pigments were formed and the content of red pigments increased.

Oligosaccharide Inhibits Ethylene Synthesis and Stimulates Somatic Embryogenesis in a Cotton Cell Culture

The effect of a three-component oligosaccharide fragment of xyloglucan FucGalXyl (XG3) on callus-tissue growth and somatic embryogenesis was investigated in a cotton (Gossypium hirsutumL.) cell suspension culture. The oligosaccharide introduced into an induction medium at 10–8and 10–7M concentrations did not affect the frequency of callus formation from hypocotyl segments; however, it enhanced the monthly increment of callus-tissue weight 1.5- and 3-fold, respectively. Induction and culturing of the callus on an XG3-containing medium adversely affected its morphogenetic potential. Addition of XG3 to the culture medium during the cell suspension preparation stimulated cell division resulting, after 40 days, in a 3.4-fold (at 10–8M XG3) and a 1.7-fold (at 10–7M XG3) increase in the cell number as compared to the control. Exclusion of 2,4-D, kinetin, and oligosaccharide from the culture medium caused, after two weeks, a 3.8-fold increase in the number of embryos in the 10–7M XG3-treated suspension culture as compared to the control. The stimulation of somatic embryogenesis by the oligosaccharide was accompanied by a 12-fold decrease in ethylene emission. The morphogenetic effect of oligosaccharide is suggested to result from its anti-auxin action, which, in particular, inhibited the auxin-dependent ethylene synthesis.

Electrostatic Encapsulation and Growth of Plant Cell Cultures in Alginate

The growth of callus tissue from African Violets, encapsulated in alginate using electrostatics, was investigated as well as the mechanism of alginate droplet formation. Alginate microbeads as small as 500 (+/-50) microns in diameter could be produced by electrostatic extrusion directly from a plastic syringe (1900 micron extrusion orifice), in the absence of a needle. Video analysis of the mechanism of electrostatic alginate droplet formation from the syringe showed the development of a Taylor cone-like droplet which extended to form a thin strand that then broke up into droplets. Autoclaving of the alginate/medium solution significantly reduced its viscosity, giving smaller beads. Calculated microbead diameters agreed well with experimental values. Callus tissue from leaf explants was successfully immobilized and cultured using electrostatic extrusion. Tissue immobilized using 4% alginate in medium and cultured on agar grew best, producing a complete plantlet within four months. The long-term aim is to develop an effective method for large production of artificial seeds.

Effect of 5-Aminouracil on Callus Tissue Growth and Mdh Genes Expression in Cereus peruvianus (Cactaceae).

An unexpected growth-stimulating effect of 5-aminouracil (5-AU) 50, 100 and 150 μM concentration on long-term callus tissue culture of Cereus peruvianus was found during investigations of callus tissue growth and expression of Mdh genes in the presence of this inhibitor of DNA replication. Three-year-old callus tissues were cut and subcultured in culture medium containing the different 5-AU concentrations. The callus tissues were then collected at 15-day intervals up to 45 days to determine individual callus weight. At 45 days, the callus tissues were collected and submitted to starch gel electrophoresis for analysis of MDH isozymes. The in vivo effect of the various 5-AU concentrations on onion root-tip cell growth was also investigated, and a similar growth response pattern was observed. Unchanged MDH isozyme patterns in callus tissues indicated that Mdh gene expression was not directly related to increased growth of the callus tissues. The interference of 5-AU with DNA replication for cell proliferation and tissue did not change the expression of Mdh genes at the transcriptional level but seems to affect important genes that modulate enzyme-specific activity or degradation of MDH isozymes.

Differential alcohol dehydrogenase and malate dehydrogenase isozyme expression in long-term callus tissue cultures of Cereus peruvianus (Cactaceae).

Alcohol dehydrogenase (ADH) and mitochondrial malate dehydrogenase (mMDH) isozymes were tested as markers to study the effect of a high kinetin concentration on isozyme phenotypes and on the development of Cereus peruvianus callus tissue culture. Three-year-old callus tissues were used as samples. Callus tissue samples grown on 4.0 mg/L 2,4-dichlorophenoxyacetic acid (2,4-D) and on 4.0 and 8.0 mg/L N-(2-furanylmethyl)-1H-purine-6 amine (kinetin) were cut and transferred to fresh medium containing 4.0 mg/L 2,4-D and 4.0, 8.0, 16.0, and 32 mg/L kinetin combinations. The pattern of changes observed in the ADH and mMDH isozymes as well as the growth of callus tissues was independent of the concentrations tested. The various ADH and mMDH isozymes seem to be products of differential association of subunits of the two Adh and two mMdh genes. Both genes are active throughout callus tissue development; however, gene expression changed with various callus culture condictions. This study addresses how long-term callus culture condictions affect constitutive and differential gene expression of the Adh and mMdh genes in C. peruvianus.

Iron Chelate Photodegradation in Fertilizer and Nutrient Solutions Affect Iron Acquisition

Iron chelate photodegradation is a problem in tissue culture where limited soluble Fe in agar reduces callus tissue growth. Our objectives were to determine if Fe chelate photodegradation occurs in commercial fertilizers used in greenhouse plant production and, if so, the effects on plant Fe acquisition. Commercial 20N–10P–20K soluble fertilizers containing Fe-EDTA were prepared as 100x stocks based on a 100 mg N/liter (1x) concentration. A modified Hoagland's solution with Fe-DTPA was prepared as a 10x stock based on a 200 mg N/liter (1x) concentration. Samples then were kept in darkness or were irradiated with 500 μmol·m–2·s–1 from fluorescent and incandescent sources for ≤240 hours. Soluble Fe in the irradiated commercial fertilizer solutions decreased 85% in 240 h. Soluble Fe in the Hoagland's solution, prepared in the lab, decreased 97% in 72 h. There was no loss in soluble Fe in any dark-stored treatment; demonstrating photodegradation of Fe-chelates under commercial settings. Excised roots of marigold (Tagetes erecta L.), grown hydroponically in the irradiated solutions, had Fe(III)-DTPA reductase activity 2 to 6 times greater than roots of plants grown in solutions kept in darkness. Plants growing in irradiated solutions acidified the rhizosphere more than plants growing in solutions kept dark. The increase in Fe reductase activity and rhizosphere acidification are Fe-efficiency reactions of marigold responding to the photodegradation of Fe-chelates and subsequent decrease in soluble Fe in both commercial fertilizers and lab-prepared nutrient solution.

Effect of Synthetic Auxin and Cytokinin on the Growth of Callus Tissues from Nicotiana Tabacum CMS/81

ABSTRACTThe influence of new synthetic auxin hydrazide of 4-chlorophenoxyacetic acid (H-4-CPA) and cytokinin 1-(3-chlorophenyl)-3-[2-(4-methyl)pyridyl]-2-urea (3-CP-4-MPU) on the growth of callus tissues from tobacco was investigated. The substances were applied exogenously to the autoclaved nutrient medium independently and in combination at both concentrations: 0.5 mg/l and 4.0 mg/l. 3-CP-4-MPU (0.5 mg/l or 1.9 μ M) manifested higher growth stimulating effect than kinetin (0.2 μ M—standard I). Kinetin at concentration 1.9 μ M equimolar to that of the used phenylurea cytokinin inhibited the growth of tobacco calli. The high concentration of 3-CP-4-MPU (4.0 mg/l or 15.2 μ M) stronfly reduced the fresh and dry weight, therefore the phenylurea cytokinin is an inhibitor for this plant system at concentration 8-fold higher than that of kinetin. H-4-CPA increased the tobacco callus growth at both used concentrations. The simultaneous application of 1.9 μ M 3-CP-4-MPU and 2.5 μ M H-4-CPA to tobacco callus accel...