N. 1993. Polyamine metabolism and ethylene biosynthesis in normal and habituated sugar beet callu... more N. 1993. Polyamine metabolism and ethylene biosynthesis in normal and habituated sugar beet callus. -Physiol. Plant. 89: 699-706.
ABSTRACT Malondialdehyde (TBARS: thiobarbituric acid reactive substances) has been investigated i... more ABSTRACT Malondialdehyde (TBARS: thiobarbituric acid reactive substances) has been investigated in non-organogenic and organogenic habituated and normal sugarbeet cell lines and compared with lipid hydroperoxides, conjugated diene formation and lipoxygenase activity in order to estimate the reality of lipid peroxidation processes which have been postulated in the habituated non-organogenic cell line. The results presented here exhibit a strong discrepancy between TBARS and the other indices tested. Neither hydroperoxide index, nor conjugated dienes, nor lipoxygenase activity could confirm that the non-organogenic habituated cells studied were submitted to permanent stress due to free radical attacks. Moreover, these results underlined that the use of TBARS to estimate lipid peroxidation must be considered with extreme caution in plants and can lead to misinterpretations.
Plant development is influenced by changes in the levels and types of sugars produced metabolical... more Plant development is influenced by changes in the levels and types of sugars produced metabolically. The normal (N), habituated organogenic (HO) and habituated nonorganogenic (HNO) sugar beet cell lines originate from the same mother plant but exhibit distinct levels of morphogenesis and differentiation, and contain different levels of simple carbohydrates. We aim to elucidate whether differences in the abundance and activity of enzymes involved in carbohydrate metabolism and sugar sensing/signalling help explain the different carbohydrate profiles and differentiation states of the cell lines. Using 13 C NMR spectroscopy to analyze cultures of the cell lines over 28 days, we found that N cells accumulated sucrose; HO cells sucrose, glucose and fructose; and HNO cells glucose and fructose. Of three invertase isoforms, the activity of cell wall invertase (CWI) was highest in all the cell lines, and CWI activity was greatest in HNO line. The specific accumulation of intracellular carbohydrates during subculture correlated strongly with CWI activity but less so with the vacuolar and cytoplasmic invertase isoforms, or with sucrose synthase activity. Cell lines showed differences in how sugars regulated invertase and sucrose synthase activity. The role of sugar sensing in the regulation of CWI activity was investigated in the cell lines using glucose and sucrose, as well as carbohydrate analogues such as mannitol, 2-O-deoxyglucose and 3-O-methylglucose. Differences in the regulation of CWI activity by carbohydrates across the three cell lines suggest that CWI can be fine-tuned according to the specific carbohydrate requirements of each line during growth. Differences in sugar signalling pathways across the cell lines were explored using glucose and sucrose in the presence of inhibitors of protein kinases or phosphatases. Taken together, our findings suggest that specific regulation of CWI activity plays an important role in determining the intracellular carbohydrate levels of sugar beet cell lines, and possibly their differentiation state as well.
Normal, habituated and transformed in vitro tissue lines of sugar beet (Beta 6ulgaris L.), horser... more Normal, habituated and transformed in vitro tissue lines of sugar beet (Beta 6ulgaris L.), horseradish (Armoracia lapathifolia Gilib.) and potato (Solanum tuberosum L.) were studied with regard to isoesterase patterns. Isoenzymes were separated in gradient gels (5 -12%) of polyacrylamide and by isoelectric focussing in pH range 4 -9. 1-and 2-naphtylacetate were used as substrates of broad spectrum which cover also esterases (arylesterases and carboxylesterases) reacting with organophosphorous compounds. Distinct isoesterase patterns were noticed in sugar beet normal, habituated and crown gall tumour tissues. Horseradish tumour and teratoma, on the contrary, differed only in one anodic isoenzyme. Even the malformed shoots and unorganised tissue of teratoma had the same patterns. In potato tuber tissue, change in isoesterase pattern, characterised by disappearance of a dominant dark area, was observed during tumour development. The gradient gels gave more stable and reproducible isoenzyme patterns than isoelectric focussing.
Comptes Rendus de l Académie des Sciences - Series III - Sciences de la Vie
Isolation of homologous ras-related genes from sugar beet has never been reported. Screening cDNA... more Isolation of homologous ras-related genes from sugar beet has never been reported. Screening cDNA library from Beta vulgaris L. Hilma resulted in the isolation of 3 ras-homologous clones. Two of these genes (rab1Bv and rab2Bv) belong to the Rab/Ypt group. The deduced polypeptidic sequences from them show strong homologies to Ara3 (93% with Rab1Bv) of Arabidopsis thaliana and Rgp2 (97% with Rab2Bv) of Oryza sativa. The third gene (rho1Bv) belongs to the Rho family. The homology of Rho1Bv protein with Rho1Ps from Pisum is very high (98%). Rho1Bv is the second representative plant Rho protein described in the literature. The homologies of all these 3 small GTP-binding proteins indicate that these proteins are conserved in plant families like Chenopodiaceae, Brassicaceae, Fabaceae and Poaceae and could control important transductional pathways conserved along the processes of evolution.
Plant Cell, Tissue and Organ Culture (PCTOC), 2015
Your article is protected by copyright and all rights are held exclusively by Springer Science +B... more Your article is protected by copyright and all rights are held exclusively by Springer Science +Business Media Dordrecht. This e-offprint is for personal use only and shall not be selfarchived in electronic repositories. If you wish to self-archive your article, please use the accepted manuscript version for posting on your own website. You may further deposit the accepted manuscript version in any repository, provided it is only made publicly available 12 months after official publication or later and provided acknowledgement is given to the original source of publication and a link is inserted to the published article on Springer's website. The link must be accompanied by the following text: "The final publication is available at link.springer.com".
Over the past decade, medicinal plants have received considerable interest for their phytomedicin... more Over the past decade, medicinal plants have received considerable interest for their phytomedicinal chemical compounds. Among them Hypericum perforatum L. has been considered according to its biochemical characteristics and secondary metabolite production. The main goal of the research was to summarize the influence of plant growth regulators on secondary metabolite production including hypericin and pseudohypericin in Hypericum in vitro regenerated plantlets. A reversed-phase high performance liquid chromatography (HPLC) method was developed for analyzing of secondary metabolites. The specific accumulation of secondary metabolites in in vitro cultures was influenced by phytohormonal supplementation of the medium. Combination of auxin and cytokinin concentrations improved the production of secondary metabolites.
Plants sense carbohydrates and transduce a signal which changes gene expression and the activitie... more Plants sense carbohydrates and transduce a signal which changes gene expression and the activities of many enzymes. The relationship between changes in gene expression by carbohydrates and the developmental state of the cells is still poorly understood. To gain more knowledge about this relationship, we have analyzed three sugar beet (Beta vulgaris L.) in vitro cell lines residing on distinct differentiation states. Cell suspensions were initiated and cells were incubated for 72h in the medium with sucrose as a control, or treated during the same period with glucose or 3-O-methylglucose (3OMG). Cellular and extracellular proteins, separated electrophoretically, showed that sugar-induced protein expression was cell line-specific. More differences were visible in extracellular and in glycoprotein than on cellular protein patterns. The 3OMG downregulated while glucose upregulated cellular glycoproteins. In the case of extracellular proteins, glucose and 3OMG were equally effective in b...
Summary Cells from a fully habituated nonorganogenic sugarbeet callus line show very large nuclei... more Summary Cells from a fully habituated nonorganogenic sugarbeet callus line show very large nuclei, that are very irregular in shape, with deep invaginations and many nucleoli. Micronuclei can also be seen. Fluorimetric analyses of the DNA content in the habituated cells show an abnormal distribution indicating polyploidy and aneuploidy. Such features closely resemble those observed in animal cancer cells.
ABSTRACT Malondialdehyde (TBARS: thiobarbituric acid reactive substances) has been investigated i... more ABSTRACT Malondialdehyde (TBARS: thiobarbituric acid reactive substances) has been investigated in non-organogenic and organogenic habituated and normal sugarbeet cell lines and compared with lipid hydroperoxides, conjugated diene formation and lipoxygenase activity in order to estimate the reality of lipid peroxidation processes which have been postulated in the habituated non-organogenic cell line. The results presented here exhibit a strong discrepancy between TBARS and the other indices tested. Neither hydroperoxide index, nor conjugated dienes, nor lipoxygenase activity could confirm that the non-organogenic habituated cells studied were submitted to permanent stress due to free radical attacks. Moreover, these results underlined that the use of TBARS to estimate lipid peroxidation must be considered with extreme caution in plants and can lead to misinterpretations.
Bare-root seedlings of pedunculate oak (Quercus robur L.) and northern red oak (Quercus rubra L.)... more Bare-root seedlings of pedunculate oak (Quercus robur L.) and northern red oak (Quercus rubra L.) were lifted in January and stored at 1.8°C, at 82% relative humidity, until their fresh weight declined by 33%. Root growth potential (RGP), fine root electrolyte leakage (REL), fine root water content (RWC), shoot tip water content (SWC), starch and metabolic solute contents in root and shoot, were measured just after lifting and after treatment. Survival of treated seedlings was also assessed in a field trial. RWC, SWC, REL, RGP were dramatically affected by desiccation during cold storage. In both species, root soluble carbohydrate level, inositol level and isocitrate level increased, whereas root starch level and shoot soluble carbohydrate level decreased. In northern red oak, treated seedlings had higher root contents of soluble carbohydrates, inositol and proline than in pedunculate oak. Moreover, treatment induced proline accumulation only in northern red oak roots. These differences could explain why field survival of treated seedlings was significantly better in northern red oak than in pedunculate oak.
ABSTRACT Summary NMR (nuclear magnetic resonance) spectroscopy was used to identify metabolic sol... more ABSTRACT Summary NMR (nuclear magnetic resonance) spectroscopy was used to identify metabolic solutes in one normal and two habituated sugarbeet cell lines (Beta vulgaris L.altissima) obtained from the same mother strain. This technique was applied to investigate the intracellular naturally occurring13C isotopes (1.1% of total natural carbon) in living sugarbeet suspension cells and perchloric cell extracts. A combination of1H,13C, double-quantum filter correlation spectroscopy, heteronuclear multiple-bond correlation, and heteronuclear multiple-quantum coherence spectra from perchloric cell extracts enabled us to identify the main compounds in the different extract solutions. This was verified by spiking the solutions with small amounts of reference compounds to exclude the influence exerted by pH on the chemical shifts of the different compounds in the1H and13C spectra. The comparison of the three sugarbeet cell lines' NMR spectra showed the presence of sucrose, glucose, and fructose in the three strains. On the other hand, it revealed a strong discrepancy between metabolic solutes. Spectra from the habituated lines showed the presence of glutamine. Some amino acids such as alanine or valine, and unidentified signals corresponding to aromatic rings were only characterized in the habituated nonorganogenic cells. On the basis of these13C NMR data we assumed that the discrepancy between the different sugarbeet cell lines could be due to an increase in the metabolic activity of the habituated cell lines in relation to their autonomous growth.
Plant Cell, Tissue and Organ Culture (PCTOC), 2012
Normal (N), habituated nonorganogenic (HNO), and tumour (T) sugar beet cell lines were analysed i... more Normal (N), habituated nonorganogenic (HNO), and tumour (T) sugar beet cell lines were analysed in order to establish specific patterns of extracellular proteins and identify protein markers that might explain the distinct phenotypical characteristics. Electron microscopy showed that the ultrastructure of N cells corresponds to that of parenchyma cells, and that these cells contain plastids with large starch grains. HNO and T cells had enlarged, lobed nuclei with an increased number of nucleoli; the number of nuclei in HNO cells was greater than in T cells. The T plastids were elongated, with reduced thylakoids and abundant phytoferritin deposits, while HNO plastids were small and vacuolated, with an irregular, underdeveloped thylakoid system. The extracellular proteome of the cells was separated by sodium dodecyl sulphate polyacrylamide gel electrophoresis. Greater differences in protein expression were observed between the HNO and N lines than between the T and N lines. Sixteen of the most prominent bands differentially expressed among the cell lines were cut out from the gel and analyzed by mass spectrometry. Cell wall-modifying enzymes were identified, including a peroxidase whose expression was twofold higher in N and T tissue than in HNO tissue; pectinesterase, which was expressed at a level threefold lower in the T line than in the other cell lines; and xyloglucan endotransglucosylase, which was expressed at a level sixfold higher in HNO and T tissue. Three proteins belonged to the chitinase gene family and their expression was higher in HNO and T tissue than in N tissue. The differential expression of these proteins suggests that these play a role in cell line-specific cell wall composition and cell-to-cell adhesion.
N. 1993. Polyamine metabolism and ethylene biosynthesis in normal and habituated sugar beet callu... more N. 1993. Polyamine metabolism and ethylene biosynthesis in normal and habituated sugar beet callus. -Physiol. Plant. 89: 699-706.
M. 1991. When plant teratomas turn into cancers in the absence of pathogens. -Physiol, Piant. 83:... more M. 1991. When plant teratomas turn into cancers in the absence of pathogens. -Physiol, Piant. 83: 696-701.
. A comparison between ethylene production, ACC and mACC contents, and hydroperoxide level in nor... more . A comparison between ethylene production, ACC and mACC contents, and hydroperoxide level in normal and habituated sugar beet calli. -Physiol. Plant. 82: 397-400.
ABSTRACT Northern analysis of RNAs, extracted from normal sugarbeet callus cultures (grown with g... more ABSTRACT Northern analysis of RNAs, extracted from normal sugarbeet callus cultures (grown with growth regulators) and from leaves derived from the mother strain, when hybridized with a Xenopus c-Ki-ras probe, reveal the presence of two transcripts in the plant material. The level of RNA detected is slightly higher (approximately 2 fold) in callus culture, when compared with leaves from the mother strain. Involvement of cellular oncogenes in the control of plant cells cultured in vitro is suggested.
N. 1993. Polyamine metabolism and ethylene biosynthesis in normal and habituated sugar beet callu... more N. 1993. Polyamine metabolism and ethylene biosynthesis in normal and habituated sugar beet callus. -Physiol. Plant. 89: 699-706.
ABSTRACT Malondialdehyde (TBARS: thiobarbituric acid reactive substances) has been investigated i... more ABSTRACT Malondialdehyde (TBARS: thiobarbituric acid reactive substances) has been investigated in non-organogenic and organogenic habituated and normal sugarbeet cell lines and compared with lipid hydroperoxides, conjugated diene formation and lipoxygenase activity in order to estimate the reality of lipid peroxidation processes which have been postulated in the habituated non-organogenic cell line. The results presented here exhibit a strong discrepancy between TBARS and the other indices tested. Neither hydroperoxide index, nor conjugated dienes, nor lipoxygenase activity could confirm that the non-organogenic habituated cells studied were submitted to permanent stress due to free radical attacks. Moreover, these results underlined that the use of TBARS to estimate lipid peroxidation must be considered with extreme caution in plants and can lead to misinterpretations.
Plant development is influenced by changes in the levels and types of sugars produced metabolical... more Plant development is influenced by changes in the levels and types of sugars produced metabolically. The normal (N), habituated organogenic (HO) and habituated nonorganogenic (HNO) sugar beet cell lines originate from the same mother plant but exhibit distinct levels of morphogenesis and differentiation, and contain different levels of simple carbohydrates. We aim to elucidate whether differences in the abundance and activity of enzymes involved in carbohydrate metabolism and sugar sensing/signalling help explain the different carbohydrate profiles and differentiation states of the cell lines. Using 13 C NMR spectroscopy to analyze cultures of the cell lines over 28 days, we found that N cells accumulated sucrose; HO cells sucrose, glucose and fructose; and HNO cells glucose and fructose. Of three invertase isoforms, the activity of cell wall invertase (CWI) was highest in all the cell lines, and CWI activity was greatest in HNO line. The specific accumulation of intracellular carbohydrates during subculture correlated strongly with CWI activity but less so with the vacuolar and cytoplasmic invertase isoforms, or with sucrose synthase activity. Cell lines showed differences in how sugars regulated invertase and sucrose synthase activity. The role of sugar sensing in the regulation of CWI activity was investigated in the cell lines using glucose and sucrose, as well as carbohydrate analogues such as mannitol, 2-O-deoxyglucose and 3-O-methylglucose. Differences in the regulation of CWI activity by carbohydrates across the three cell lines suggest that CWI can be fine-tuned according to the specific carbohydrate requirements of each line during growth. Differences in sugar signalling pathways across the cell lines were explored using glucose and sucrose in the presence of inhibitors of protein kinases or phosphatases. Taken together, our findings suggest that specific regulation of CWI activity plays an important role in determining the intracellular carbohydrate levels of sugar beet cell lines, and possibly their differentiation state as well.
Normal, habituated and transformed in vitro tissue lines of sugar beet (Beta 6ulgaris L.), horser... more Normal, habituated and transformed in vitro tissue lines of sugar beet (Beta 6ulgaris L.), horseradish (Armoracia lapathifolia Gilib.) and potato (Solanum tuberosum L.) were studied with regard to isoesterase patterns. Isoenzymes were separated in gradient gels (5 -12%) of polyacrylamide and by isoelectric focussing in pH range 4 -9. 1-and 2-naphtylacetate were used as substrates of broad spectrum which cover also esterases (arylesterases and carboxylesterases) reacting with organophosphorous compounds. Distinct isoesterase patterns were noticed in sugar beet normal, habituated and crown gall tumour tissues. Horseradish tumour and teratoma, on the contrary, differed only in one anodic isoenzyme. Even the malformed shoots and unorganised tissue of teratoma had the same patterns. In potato tuber tissue, change in isoesterase pattern, characterised by disappearance of a dominant dark area, was observed during tumour development. The gradient gels gave more stable and reproducible isoenzyme patterns than isoelectric focussing.
Comptes Rendus de l Académie des Sciences - Series III - Sciences de la Vie
Isolation of homologous ras-related genes from sugar beet has never been reported. Screening cDNA... more Isolation of homologous ras-related genes from sugar beet has never been reported. Screening cDNA library from Beta vulgaris L. Hilma resulted in the isolation of 3 ras-homologous clones. Two of these genes (rab1Bv and rab2Bv) belong to the Rab/Ypt group. The deduced polypeptidic sequences from them show strong homologies to Ara3 (93% with Rab1Bv) of Arabidopsis thaliana and Rgp2 (97% with Rab2Bv) of Oryza sativa. The third gene (rho1Bv) belongs to the Rho family. The homology of Rho1Bv protein with Rho1Ps from Pisum is very high (98%). Rho1Bv is the second representative plant Rho protein described in the literature. The homologies of all these 3 small GTP-binding proteins indicate that these proteins are conserved in plant families like Chenopodiaceae, Brassicaceae, Fabaceae and Poaceae and could control important transductional pathways conserved along the processes of evolution.
Plant Cell, Tissue and Organ Culture (PCTOC), 2015
Your article is protected by copyright and all rights are held exclusively by Springer Science +B... more Your article is protected by copyright and all rights are held exclusively by Springer Science +Business Media Dordrecht. This e-offprint is for personal use only and shall not be selfarchived in electronic repositories. If you wish to self-archive your article, please use the accepted manuscript version for posting on your own website. You may further deposit the accepted manuscript version in any repository, provided it is only made publicly available 12 months after official publication or later and provided acknowledgement is given to the original source of publication and a link is inserted to the published article on Springer's website. The link must be accompanied by the following text: "The final publication is available at link.springer.com".
Over the past decade, medicinal plants have received considerable interest for their phytomedicin... more Over the past decade, medicinal plants have received considerable interest for their phytomedicinal chemical compounds. Among them Hypericum perforatum L. has been considered according to its biochemical characteristics and secondary metabolite production. The main goal of the research was to summarize the influence of plant growth regulators on secondary metabolite production including hypericin and pseudohypericin in Hypericum in vitro regenerated plantlets. A reversed-phase high performance liquid chromatography (HPLC) method was developed for analyzing of secondary metabolites. The specific accumulation of secondary metabolites in in vitro cultures was influenced by phytohormonal supplementation of the medium. Combination of auxin and cytokinin concentrations improved the production of secondary metabolites.
Plants sense carbohydrates and transduce a signal which changes gene expression and the activitie... more Plants sense carbohydrates and transduce a signal which changes gene expression and the activities of many enzymes. The relationship between changes in gene expression by carbohydrates and the developmental state of the cells is still poorly understood. To gain more knowledge about this relationship, we have analyzed three sugar beet (Beta vulgaris L.) in vitro cell lines residing on distinct differentiation states. Cell suspensions were initiated and cells were incubated for 72h in the medium with sucrose as a control, or treated during the same period with glucose or 3-O-methylglucose (3OMG). Cellular and extracellular proteins, separated electrophoretically, showed that sugar-induced protein expression was cell line-specific. More differences were visible in extracellular and in glycoprotein than on cellular protein patterns. The 3OMG downregulated while glucose upregulated cellular glycoproteins. In the case of extracellular proteins, glucose and 3OMG were equally effective in b...
Summary Cells from a fully habituated nonorganogenic sugarbeet callus line show very large nuclei... more Summary Cells from a fully habituated nonorganogenic sugarbeet callus line show very large nuclei, that are very irregular in shape, with deep invaginations and many nucleoli. Micronuclei can also be seen. Fluorimetric analyses of the DNA content in the habituated cells show an abnormal distribution indicating polyploidy and aneuploidy. Such features closely resemble those observed in animal cancer cells.
ABSTRACT Malondialdehyde (TBARS: thiobarbituric acid reactive substances) has been investigated i... more ABSTRACT Malondialdehyde (TBARS: thiobarbituric acid reactive substances) has been investigated in non-organogenic and organogenic habituated and normal sugarbeet cell lines and compared with lipid hydroperoxides, conjugated diene formation and lipoxygenase activity in order to estimate the reality of lipid peroxidation processes which have been postulated in the habituated non-organogenic cell line. The results presented here exhibit a strong discrepancy between TBARS and the other indices tested. Neither hydroperoxide index, nor conjugated dienes, nor lipoxygenase activity could confirm that the non-organogenic habituated cells studied were submitted to permanent stress due to free radical attacks. Moreover, these results underlined that the use of TBARS to estimate lipid peroxidation must be considered with extreme caution in plants and can lead to misinterpretations.
Bare-root seedlings of pedunculate oak (Quercus robur L.) and northern red oak (Quercus rubra L.)... more Bare-root seedlings of pedunculate oak (Quercus robur L.) and northern red oak (Quercus rubra L.) were lifted in January and stored at 1.8°C, at 82% relative humidity, until their fresh weight declined by 33%. Root growth potential (RGP), fine root electrolyte leakage (REL), fine root water content (RWC), shoot tip water content (SWC), starch and metabolic solute contents in root and shoot, were measured just after lifting and after treatment. Survival of treated seedlings was also assessed in a field trial. RWC, SWC, REL, RGP were dramatically affected by desiccation during cold storage. In both species, root soluble carbohydrate level, inositol level and isocitrate level increased, whereas root starch level and shoot soluble carbohydrate level decreased. In northern red oak, treated seedlings had higher root contents of soluble carbohydrates, inositol and proline than in pedunculate oak. Moreover, treatment induced proline accumulation only in northern red oak roots. These differences could explain why field survival of treated seedlings was significantly better in northern red oak than in pedunculate oak.
ABSTRACT Summary NMR (nuclear magnetic resonance) spectroscopy was used to identify metabolic sol... more ABSTRACT Summary NMR (nuclear magnetic resonance) spectroscopy was used to identify metabolic solutes in one normal and two habituated sugarbeet cell lines (Beta vulgaris L.altissima) obtained from the same mother strain. This technique was applied to investigate the intracellular naturally occurring13C isotopes (1.1% of total natural carbon) in living sugarbeet suspension cells and perchloric cell extracts. A combination of1H,13C, double-quantum filter correlation spectroscopy, heteronuclear multiple-bond correlation, and heteronuclear multiple-quantum coherence spectra from perchloric cell extracts enabled us to identify the main compounds in the different extract solutions. This was verified by spiking the solutions with small amounts of reference compounds to exclude the influence exerted by pH on the chemical shifts of the different compounds in the1H and13C spectra. The comparison of the three sugarbeet cell lines' NMR spectra showed the presence of sucrose, glucose, and fructose in the three strains. On the other hand, it revealed a strong discrepancy between metabolic solutes. Spectra from the habituated lines showed the presence of glutamine. Some amino acids such as alanine or valine, and unidentified signals corresponding to aromatic rings were only characterized in the habituated nonorganogenic cells. On the basis of these13C NMR data we assumed that the discrepancy between the different sugarbeet cell lines could be due to an increase in the metabolic activity of the habituated cell lines in relation to their autonomous growth.
Plant Cell, Tissue and Organ Culture (PCTOC), 2012
Normal (N), habituated nonorganogenic (HNO), and tumour (T) sugar beet cell lines were analysed i... more Normal (N), habituated nonorganogenic (HNO), and tumour (T) sugar beet cell lines were analysed in order to establish specific patterns of extracellular proteins and identify protein markers that might explain the distinct phenotypical characteristics. Electron microscopy showed that the ultrastructure of N cells corresponds to that of parenchyma cells, and that these cells contain plastids with large starch grains. HNO and T cells had enlarged, lobed nuclei with an increased number of nucleoli; the number of nuclei in HNO cells was greater than in T cells. The T plastids were elongated, with reduced thylakoids and abundant phytoferritin deposits, while HNO plastids were small and vacuolated, with an irregular, underdeveloped thylakoid system. The extracellular proteome of the cells was separated by sodium dodecyl sulphate polyacrylamide gel electrophoresis. Greater differences in protein expression were observed between the HNO and N lines than between the T and N lines. Sixteen of the most prominent bands differentially expressed among the cell lines were cut out from the gel and analyzed by mass spectrometry. Cell wall-modifying enzymes were identified, including a peroxidase whose expression was twofold higher in N and T tissue than in HNO tissue; pectinesterase, which was expressed at a level threefold lower in the T line than in the other cell lines; and xyloglucan endotransglucosylase, which was expressed at a level sixfold higher in HNO and T tissue. Three proteins belonged to the chitinase gene family and their expression was higher in HNO and T tissue than in N tissue. The differential expression of these proteins suggests that these play a role in cell line-specific cell wall composition and cell-to-cell adhesion.
N. 1993. Polyamine metabolism and ethylene biosynthesis in normal and habituated sugar beet callu... more N. 1993. Polyamine metabolism and ethylene biosynthesis in normal and habituated sugar beet callus. -Physiol. Plant. 89: 699-706.
M. 1991. When plant teratomas turn into cancers in the absence of pathogens. -Physiol, Piant. 83:... more M. 1991. When plant teratomas turn into cancers in the absence of pathogens. -Physiol, Piant. 83: 696-701.
. A comparison between ethylene production, ACC and mACC contents, and hydroperoxide level in nor... more . A comparison between ethylene production, ACC and mACC contents, and hydroperoxide level in normal and habituated sugar beet calli. -Physiol. Plant. 82: 397-400.
ABSTRACT Northern analysis of RNAs, extracted from normal sugarbeet callus cultures (grown with g... more ABSTRACT Northern analysis of RNAs, extracted from normal sugarbeet callus cultures (grown with growth regulators) and from leaves derived from the mother strain, when hybridized with a Xenopus c-Ki-ras probe, reveal the presence of two transcripts in the plant material. The level of RNA detected is slightly higher (approximately 2 fold) in callus culture, when compared with leaves from the mother strain. Involvement of cellular oncogenes in the control of plant cells cultured in vitro is suggested.
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