Aspects of Photosynthetic Plant Tissue Cultures

Horn, Michael E.; Widholm, Jack M.

doi:10.1007/978-94-009-6207-1_5

Cited by 28 publications

(16 citation statements)

References 125 publications

(86 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In many respects S25 cells resemble what are described in the literature as photomixotrophic cells (Horn and Widholm, 1984). Photomixotrophic cultures are usually obtained by subculturing heterotrophic cells into media that promote culture greening, especially in media containing lower carbohydrate content, although photomixotrophic cells require both a supply of carbohydrate and light for optimal growth.…”

Section: Discussionmentioning

confidence: 96%

Photosynthesis in Salt-Adapted Heterotrophic Tobacco Cells and Regenerated Plants

et al. 1996

View full text Add to dashboard Cite

Tobacco (Nicofiana tabacum L.) cells growing heterotrophically in the light on supplied sucrose (SO) have previously been adapted to grow in 428 mM NaCl (S25). Among the changes occurring in salinity-adapted cell cultures are (a) elevated levels of chlorophyll compared to unadapted cells; (b) decreased levels of starch; (c) alterations in chloroplast ultrastructure, including loss of starch grains, increased thylakoid membrane structure, and the presence of plastoglobules; and (d) increased rates of O, evolution, CO, fixation, and photophosphorylation relative to SO cells. These latter changes apparently derive from the fact that thylakoid membranes in S25 cells contain higher levels of photosystem I-and 11-associated proteins as well as thylakoid ATPase components. S25 chloroplasts contain immunologically detectable levels of ribulose-1 ,S-bisphosphate carboxylase/oxygenase, whereas SO completely lack the enzyme. These changes taken together suggest that even in the presente of sucrose, S25 cells have acquired a significant degree of salt-tolerant photosynthetic competence. This salt-tolerant photoysynthetic capability manifests itself in plants backcrossed with normal plants for three generations. These plants contain chloroplasts that demonstrate in vitro more salt-tolerant CO, fixation, O, evolution, and photophosphorylation than do backcross progeny of plants regenerated from SO cultures.Numerous cell-suspension culture lines able to grow in the presence of salt-induced osmotic stress have been established (Dix and Street, 1975;Nabors et al., 1975;Tyagi et al., 1981;Kochba et al., 1982; Rangan and Vasil, 1983;Watad et al., 1983;Pandey and Ganapathy, 1984; Binzel et al., 1985;Rains, 1989;Plaut et al., 1991) for the purpose of studying cellular adaptation to salinity stress, and these cell lines have provided much information about salinity tolerance at the cellular level. The tobacco cell line chosen for the present study has been widely studied in this regard. Binzel et al. (1985) established a heterotrophically growing, salt-adapted cell line of tobacco (Nicotiana tabacum L. var Wisconsin 38) by gradually adapting cells to increasing concentrations of NaC1. The adapted cell line showed substantially greater growth in salt-containing media than did previously unadapted cells. However, adapted cells growing in salt showed reduced cell expansion and fresh weight gain but equivalent dry weight gain ' This is publication No. 6-955101 of the Alabama Agricultura1 (Binzel et al., 1985;Bressan et al., 1990) when compared to unadapted cells growing without salt.Adaptation of tobacco cells to salt has also been shown to involve the accumulation of a 26-kD, thaumatin-like protein, called osmotin (Ericson and Alfinito, 1984;Singh et al., 1985Singh et al., , 1987; alterations in the cell wall and extracellular polysaccharides (Iraki et al., 1989a(Iraki et al., , 1989b; the accumulation of various osmolytes, including Suc and Pro (Binzel et al., 1987); and the accumulation and partitioning of inorganic ions such as p...

show abstract

Section: Discussionmentioning

confidence: 96%

Photosynthesis in Salt-Adapted Heterotrophic Tobacco Cells and Regenerated Plants

et al. 1996

View full text Add to dashboard Cite

show abstract

“…This indicates that the CO2 compensation concentration (r) generally was below the ambient CO2 concentration (361-373 ppm). Indeed r was 230 ± 25 ppm in SB-P cells (7)(8)(9)(10)(11)(12)(13)(14) (Fig. 3, A (Fig.…”

mentioning

confidence: 95%

Photosynthetic Characteristics of a Photoautotrophic Cell Suspension Culture of Soybean

Rogers¹,

Ogren²,

Widholm³

1987

Plant Physiol.

Self Cite

View full text Add to dashboard Cite

ABSTRACrA soybean suspension culture (SB-P) which can grow photoautotrophically in 5% CO2 will not grow in ambient CO2 levels. This elevated CO2 requirement seems to be due to the additive effects of a number of factors. The in vivo activity of ribulose-1,5-bisphosphate carboxylase (RuBPcase) is much lower in the SB-P cells, compared to soybean plants. This may be due to the low light intensity used to culture the cells, which has been shown to decrease both the amount and activity in whole plants, resulting in a low rate of net photosynthesis. The RuBPcase activation level is also lowered in air CO2 levels. The presence of the liquid medium raises the cells CO2 compensation concentration (the CO2 concentration reached when the rates of CO2 fixed by photosynthesis and the CO2 respired by the cells are equal). These factors, coupled with the high respiratory loss of CO2 all contribute to reduced net photosynthesis in air, resulting in a photosynthetic capacity that is inadequate for cell survival. Active cell division, low photosynthetic capacity, elevated respiration, and a low ratio of RuBPcase(initial)/phosphoenolpyruvate carboxylase are traits that SB-P cells share with young leaf cells, indicating SB-P cell physiology may be comparable to that of young expanding leaves rather than to that of mature leaves. (pH 5.8), and 1.5 mm NaHCO3 in a final volume of 1 ml was added to the water-jacketed vessel and illuminated at a light intensity of 400 ME m-2 s-'. The evolution rate measurements were repeated three times.14CO2 Incorporation Experiments. Duplicate flasks of cell suspensions (pH 4.5) were combined and aliquots (950 ,ul) of cells, (7.0-11.4 mg fresh weight, 6-18 Mg Chl) and a stir bar were placed in serum stoppered 16 x 55 mm glass scintillation vials. Each assay was run in triplicate. The cells were stirred and gassed with CO2 free air at 26°C under a light intensity of 400 ,E m-2 s-' for 5 min. The assays were initiated by the simultaneous injection of 25 Ml of 205 mm bicarbonate (pH 9.3, 0.89 MCi Mmol-') and 50 Ml of 1.025 M Mes (pH 1.05) to adjust pH. The final concentrations were 5 mm bicarbonate and 50 mm Mes, at a pH of 4.5 which is near that of the culture conditions. After 5 min assays were terminated by the injection of 0.5 ml of 6 N acetic acid. Incorporation of '4CO2 in the dark was carried out in the same manner with the vials being wrapped in aluminum foil. Samples were dried at 60°C, 0.5 ml of 0.5 N HCI was added to dissolve the residue, S ml scintillation cocktail added, and the dpm were determined by liquid scintillation spectrometry.Infrared Gas Exchange Analysis. Plant Physiol. Vol. 84, 1987 gas mixtures were bubbled at 400 to 475 ml min-' through the illuminated (400 ,E m-2 s-') stirred cell suspensions. To measure dark respiration the tube containing the cells was covered with aluminum foil. All measurements were taken on duplicate aliquots of SB-P, repeated twice, and the numbers averaged.CO2 Compensation Concentration (r). The CO2 compensation concentration of the cells was measu...

show abstract

“…Photoautotrophic plant cell cultures grow with minimized organic carbon in the growth medium, require constant light, and in most cases require elevated C02, 1 to 5% (7). The first photoautotrophic cultures to be established successfully were those of Bergmann (2) when green suspensions of Nicotiana tabacum var 'Samsun' were cultured with elevated CO2.…”

mentioning

confidence: 99%

“…Photosynthetic carbon metabolism and activity of enzymes involved in CO2 assimilation under varying physiological conditions have been analyzed with photoautotrophic and photomixotrophic culture systems (7,13,15,20,24). Recently it has been shown that the photoautotrophic soybean culture SB-P exhibits phytochrome-mediated responses in the lightdependent expression of genes encoding Chl a/b binding protein (10).…”

mentioning

confidence: 99%

Photosynthetic Characterization of Photoautotrophic Cells Cultured in a Minimal Medium

Goldstein¹,

Widholm²

1990

Plant Physiol.

Self Cite

View full text Add to dashboard Cite

Photosynthetic properties of photoautotrophic suspensions cultured in a minimal growth medium have been evaluated to determine whether changes have occurred in ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) activity, phosphoenol-pyruvate (PEP) carboxylase activity, chlorophyll content, or culture growth. Five photoautotrophic lines Amaranthus powellii, Datura innoxia, Glycine max, Gossypium hirsutum, and a Nicotiana tabacum-Nicotiana glutinosa fusion hybrid were grown in a medium without organic carbon other than phytohormones, and without vitamins. These photoautotrophic lines had total Rubisco activities ranging from 85 to 266 micromoles CO2 fixed per milligram chlorophyll hour-1, with percent activation of Rubisco ranging from 16 to 53%. Inclusion of protease inhibitors in the homogenization buffer did not result in higher Rubisco activity. PEP carboxylase activity for cells cultured in minimal medium was found to range from 16 to 146 micromoles CO2 per milligram chlorophyll hour-', with no higher activity in the C4 Amaranthus cells compared with PEP carboxylase activity in the C3 species assayed. Rubisco-to-PEP carboxylase ratios ranged from 2.2 to 1 up to 9.4 to 1. Chlorophyll contents increased in all but the Nicotiana cell line, and all of the photoautotrophic culture lines were capable of growth in vitamin-free medium with the exception of SB-P, which requires thiamine.

show abstract

Aspects of Photosynthetic Plant Tissue Cultures

Cited by 28 publications

References 125 publications

Photosynthesis in Salt-Adapted Heterotrophic Tobacco Cells and Regenerated Plants

Photosynthesis in Salt-Adapted Heterotrophic Tobacco Cells and Regenerated Plants

Photosynthetic Characteristics of a Photoautotrophic Cell Suspension Culture of Soybean

Photosynthetic Characterization of Photoautotrophic Cells Cultured in a Minimal Medium

Contact Info

Product

Resources

About