The toxicity of titanium dioxide nanoparticles (TiO 2-NPs), used in several applications, seems t... more The toxicity of titanium dioxide nanoparticles (TiO 2-NPs), used in several applications, seems to be influenced by their specific physicochemical characteristics. Cyto-genotoxic and inflammatory effects induced by a mixture of 79% anatase/21% rutile TiO 2-NPs were investigated in human alveolar (A549) and bronchial (BEAS-2B) cells exposed to 1-40 μg ml-1 30 min, 2 and 24 h to assess potential pulmonary toxicity. The specific physicochemical properties such as crystallinity, NP size and shape, agglomerate size, surface charge and specific surface area (SSA) were analysed. Cytotoxic effects were studied by evaluating cell viability using the WST1 assay and membrane damage using LDH analysis. Direct/oxidative DNA damage was assessed by the Fpg-comet assay and the inflammatory potential was evaluated as interleukin (IL)-6, IL-8 and tumour necrosis factor (TNF)-α release by enzyme-linked immunosorbant assay (ELISA). In A549 cells no significant viability reduction and moderate membrane damage, only at the highest concentration, were detected, whereas BEAS-2B cells showed a significant viability reduction and early membrane damage starting from 10 μg ml-1. Direct/oxidative DNA damage at 40 μg ml-1 and increased IL-6 release at 5 μg ml-1 were found only in A549 cells after 2 h. The secretion of pro-inflammatory cytokine IL-6, involved in the early acute inflammatory response, and oxidative DNA damage indicate the promotion of early and transient oxidative-inflammatory effects of tested TiO 2-NPs on human alveolar cells. The findings show a higher susceptibility of normal bronchial cells to cytotoxic effects and higher responsiveness of transformed alveolar cells to genotoxic, oxidative and early inflammatory effects induced by tested TiO 2-NPs. This different cell behaviour after TiO 2-NPs exposure suggests the use of both cell lines and multiple end-points to elucidate NP toxicity on the respiratory system.
Il volume nasce nell’ambito di un accordo di collaborazione stipulato tra il Ministero dell’Ambie... more Il volume nasce nell’ambito di un accordo di collaborazione stipulato tra il Ministero dell’Ambiente e della Tutela del Territorio e del Mare (MATTM) e il Consiglio Nazionale delle Ricerche, Dipartimento di Scienze Bio-Agroalimentari (CNR-DiSBA) e fornisce una panoramica sulla normativa internazionale in materia di Organismi Geneticamente Modificati (OGM) e dimostrare come il quadro normativo venga costantemente adeguato al continuo sviluppo scientifico nel campo delle biotecnologie
A new mutant of Arabidopsis named rha1 is characterized and the gene involved cloned. In roots, t... more A new mutant of Arabidopsis named rha1 is characterized and the gene involved cloned. In roots, the mutant shows minimal right-handed slanting, reduced gravitropic response, notable resistance to 2,4-D, but scarce resistance to IAA and NAA. The roots also show a clear resistance to the auxin transport inhibitors TIBA and NPA, and to ethylene. Other characteristics are a reduced number of lateral roots and reduced size of shoot and root in the seedlings. The gene, cloned through TAIL-PCR, was found to be a heat-shock factor that maps on chromosome 5, close to and above the RFLP marker m61. The rha1 structure, mRNA, and translation product are reported. Since, so far, no other gravitropic mutant has been described as mutated in a heat-shock factor, rha1 belongs to a new group of mutants disturbed in slanting, gravitropism, and auxin physiology. As shown through the RT-PCR analyses of its expression, the gene retains the function connected with heat shock. If the characteristics connected with auxin physiology are considered, however, it is also likely that the gene, as a transcription factor, could be involved in root circumnutation, gravitropic response, and hormonal control of differentiation. Since GUS staining under the gene promoter was localized mainly in the mature tissues, rha1 does not seem to be involved in the first steps of gravitropism, but is rather related to the general response to auxin. The alterations in slanting (mainly due to reduced chiral circumnutation) and gravitropism lead to the supposition that the two processes may have, at least in part, common origins.
Objectives According to international observations, the incidence of clinical autopsies is declin... more Objectives According to international observations, the incidence of clinical autopsies is declining worldwide, plummeting below 5% in the USA and many European countries. It is an unfavourable trend as, in 7%-12% of cases, recent clinicopathological studies found discrepancies that might have changed the therapy or the outcome if known premortem. As previous large-scale observations have examined varied patient populations, we aimed to focus on the differences between the clinical and pathological diagnostic findings in only patients who had a stroke. Material and methods We assessed the postmortem non-neuropathological and neuropathological findings of 534 consecutive patients who had a stroke who passed away. Systemic neoplasms, pneumonias, thromboembolisms and haemorrhagic transformations revealed only by autopsy were considered severe abnormalities; in addition, benign abnormalities important from an educational or scientific point of view were also recorded. Results In 26 of the 534 cases (4.9%), the presence of systemic neoplasms had already been confirmed in the clinical stage; however, 8 (1.5%) malignant tumours were only detected during autopsy. Also, 80 (15%) thromboembolic events, 73 (13.6%) pneumonias and 66 (18%) haemorrhagic transformations were only diagnosed at autopsy. Longer hospital stay (from admission to death) resulted in fewer discrepancies between clinical and autopsy diagnosis of thromboembolic events and pneumonias (p<0.01). In 169 cases, benign findings were detected. Conclusions While the type of acute stroke is reliably diagnosed with imaging techniques, postmortem autopsies are also important in patients who had a stroke as autopsies may reveal clinically silent diseases (eg, tumour), and contribute to knowing the actual incidence of strokerelated thromboembolic and pneumonia complications.
In Saccharomyces cerevisiae, Adr1 is a zinc-finger transcription factor involved in the transcrip... more In Saccharomyces cerevisiae, Adr1 is a zinc-finger transcription factor involved in the transcriptional activation of ADH2. Deletion of KlADR1, its putative ortholog in Kluyveromyces lactis, led to reduced growth in glycerol, oleate and yeast extract-peptone medium suggesting, as in S. cerevisiae, its requirement for glycerol, fatty acid and nitrogen utilization. Moreover, growth comparison on yeast extract and peptone plates showed in K. lactis a KlAdr1-dependent growth trait not present in S. cerevisiae, indicating different metabolic roles of the two factors in their environmental niches. KlADR1 is required for growth under respiratory and fermentative conditions like KlADH, alcohol dehydrogenase genes necessary for metabolic adaptation during the growth transition. Using in-gel native alcohol dehydrogenase assay, we showed that this factor affected the Adh pattern by altering the balance between these activities. Since the activity most affected by KlAdr1 is KlAdh3, a deletion analysis of the KlADH3 promoter allowed the isolation of a DNA fragment through which KlAdr1 modulated its expression. The expression of the KlADR1-GFP gene allowed the intracellular localization of the factor in K. lactis and S. cerevisiae, suggesting in the two yeasts a common mechanism of KlAdr1 translocation under fermentative and respiratory conditions. Finally, the chimeric Kl/ScADR1 gene encoding the zincfinger domains of KlAdr1 fused to the transactivating domains of the S. cerevisiae factor activated in Scadr1D the transcription of ADH2 in a ScAdr1-dependent fashion.
Journal of Biological Research - Bollettino della Società Italiana di Biologia Sperimentale, 2011
ABSTRACT The effect of microgravity on the expression of genes for tubulin, stress and aging in A... more ABSTRACT The effect of microgravity on the expression of genes for tubulin, stress and aging in Arabidopsis seedlings from wild-type, and the auxinic mutants aux 1 and eir/pin2 is reported. Simulated microgravity was produced through the Random Positioning Machine (RPM). The results showed that the tubulin genes TUA4, TUA6 and TUB2, in plants subjected to μg, showed a peak of expression at 3h in the wild-type, whereas in the mutants it was delayed to 6h. The microgravity treatment tested on the expression of stress genes FeSOD1 and CAT3 showed only a significant increase of senescence SAG12 showed increased expression in the wild-type starting at 3h, whereas in the mutant a significant increase was seen only at 24h. From the collected data we conclude that auxin transport and action should be involved in tubulin synthesis, stress, and the senescence process.
The increasing use of cobalt oxide (Co3 O4 ) nanoparticles (NPs) in several applications and the ... more The increasing use of cobalt oxide (Co3 O4 ) nanoparticles (NPs) in several applications and the suggested genotoxic potential of Co-oxide highlight the importance of evaluating Co3 O4 NPs toxicity. Cyto-genotoxic and inflammatory effects induced by Co3 O4 NPs were investigated in human alveolar (A549), and bronchial (BEAS-2B) cells exposed to 1-40 µg ml(-1) . The physicochemical properties of tested NPs were analysed by transmission electron microscopy (TEM) and dynamic light scattering (DLS). Cytotoxicity was studied to analyze cell viability (WST1 test) and membrane damage (LDH assay), direct/oxidative DNA damage was assessed by the Formamido-pyrimidine glycosylase (Fpg)-modified comet assay and inflammation by interleukin (IL)-6, IL-8 and tumor necrosis factor-alpha (TNF-α) release (ELISA). In A549 cells, no cytotoxicity was found, whereas BEAS-2B cells showed a viability reduction at 40 µg ml(-1) and early membrane damage at 1, 5 and 40 µg ml-1. In A549 cells, direct and oxidat...
A new Arabidopsis mutant is characterized (rha1) that shows, in the roots, reduced right-handed s... more A new Arabidopsis mutant is characterized (rha1) that shows, in the roots, reduced right-handed slanting, reduced gravitropism and resistance to 2,4-D, TIBA, NPA and ethylene. It also shows reduced length in the shoot and root, reduced number of lateral roots and shorter siliques. The gene was cloned through TAIL-PCR and resulted in a HSF. Because none of the known gravitropic and auxinic mutants result from damage in a HSF, rha1 seems to belong to a new class of this group of mutants. Quantitative PCR analysis showed that the expression of the gene is increased by heat and cold shock, and by presence of 2,4-D in the media. Study of the expression through the GUS reporter gene revealed increased expression in clinostated and gravistimulated plants, but only in adult tissues, and not in the apical meristems of shoots and roots.
Occupational exposure of granite workers is well known to cause lung impairment and silicosis. To... more Occupational exposure of granite workers is well known to cause lung impairment and silicosis. Toxicological profiles of different size particles of granite dust, however, are not yet understood. Present evaluation of micro- and nano-particles of granite dust as on human lung fibroblast cells IMR-90, revealed that their toxic effects were dose-dependent, and nanoparticles in general were more toxic. In this study we first demonstrated that nanoparticles caused oxidative stress, inflammatory response and genotoxicity, as seen by nearly 2 fold induction of ROS and LPO, mRNA levels of TNF-α and IL-1β, and induction in micronuclei formation. All these were significantly higher when compared with the effect of micro particles. Thus, the study suggests that separate health safety standards would be required for granite particles of different sizes.
larger objects. Taking the specific surface, "LOELs" of nano-objects (>70 m 2 /g) differ by a fac... more larger objects. Taking the specific surface, "LOELs" of nano-objects (>70 m 2 /g) differ by a factor of 5. Also the scope of the studies differs regarding the investigated effects or the related time points. Effects in lung are, however, investigated in the majority of studies so that some frequent effect like neutrophil number, total protein and LDH content in BALF, lung weight or infiltration were analyzed in more detail. Lung weight turned out as sensitive parameter for lung toxicity, although some weight gain is caused by particle burden under overload conditions. The PaFtox database offers the opportunity to investigate the available toxicological data of particles systematically and structured. This database is a nice tool e.g. for identifying physicochemical properties related to specific toxic effect e.g. to cancer.
Over the last fifteen years, an increasing number of plant scientists have become interested in t... more Over the last fifteen years, an increasing number of plant scientists have become interested in the Arabidopsis root growth pattern, that is produced on the surface of an agar plate, inclined from the vertical. In this situation, the roots wave intensely and slant preferentially towards one side, showing torsions in the epidermal cell files alternately right-and left handed. In addition, the pattern switches to the formation of large or strict coils when the plate is set horizontally. After this finding, different hypotheses were advanced attempting to explain the forces that shape these patterns. These basically appear to be gravitropism, circumnutation and negative thigmotropism. With regard to the symmetry, the coils and the slanting in the wild-type are essentially righthanded, but mutants were also reported which show a left-handed symmetry, while some do not show a regular growth pattern at all. This review article discusses the earlier as well as the most recent findings on the topic, and investigates the possibility of describing the different mechanisms shaping the root growth patterns via unifying hypothesis.
Thanks are given to the Italian National Research Council (CNR), special issue editor Dr. J. Z. K... more Thanks are given to the Italian National Research Council (CNR), special issue editor Dr. J. Z. Kiss who invited us to write the review, Beth Hazen for editing the English, Valerio Muzzini for handling the fi gures, and colleagues for useful suggestions and discussion.
KlNDE1 and KlNDI1 code for two inner mitochondrial membrane transdehydrogenases involved in the m... more KlNDE1 and KlNDI1 code for two inner mitochondrial membrane transdehydrogenases involved in the maintenance of the intracellular NAD(P)H redox balance. The function of these genes during the utilization of fermentative and respiratory carbon sources was studied. During growth in glucose, deletion of KlNDE1 and KlNDI1 led to an altered kinetic of ethanol and glycerol accumulation compared with the wild type; in addition, KlndiDelta was unable to grow in respiratory substrates. Northern analysis and GFP-fusion experiments showed that KlNDE1 and KlNDI1 regulate the expression of KlGUT2, a component of the glycerol-3-phosphate shuttle. Moreover, both genes seem to be involved in the biogenesis of the mitochondrial tubular network.
The toxicity of titanium dioxide nanoparticles (TiO 2-NPs), used in several applications, seems t... more The toxicity of titanium dioxide nanoparticles (TiO 2-NPs), used in several applications, seems to be influenced by their specific physicochemical characteristics. Cyto-genotoxic and inflammatory effects induced by a mixture of 79% anatase/21% rutile TiO 2-NPs were investigated in human alveolar (A549) and bronchial (BEAS-2B) cells exposed to 1-40 μg ml-1 30 min, 2 and 24 h to assess potential pulmonary toxicity. The specific physicochemical properties such as crystallinity, NP size and shape, agglomerate size, surface charge and specific surface area (SSA) were analysed. Cytotoxic effects were studied by evaluating cell viability using the WST1 assay and membrane damage using LDH analysis. Direct/oxidative DNA damage was assessed by the Fpg-comet assay and the inflammatory potential was evaluated as interleukin (IL)-6, IL-8 and tumour necrosis factor (TNF)-α release by enzyme-linked immunosorbant assay (ELISA). In A549 cells no significant viability reduction and moderate membrane damage, only at the highest concentration, were detected, whereas BEAS-2B cells showed a significant viability reduction and early membrane damage starting from 10 μg ml-1. Direct/oxidative DNA damage at 40 μg ml-1 and increased IL-6 release at 5 μg ml-1 were found only in A549 cells after 2 h. The secretion of pro-inflammatory cytokine IL-6, involved in the early acute inflammatory response, and oxidative DNA damage indicate the promotion of early and transient oxidative-inflammatory effects of tested TiO 2-NPs on human alveolar cells. The findings show a higher susceptibility of normal bronchial cells to cytotoxic effects and higher responsiveness of transformed alveolar cells to genotoxic, oxidative and early inflammatory effects induced by tested TiO 2-NPs. This different cell behaviour after TiO 2-NPs exposure suggests the use of both cell lines and multiple end-points to elucidate NP toxicity on the respiratory system.
Il volume nasce nell’ambito di un accordo di collaborazione stipulato tra il Ministero dell’Ambie... more Il volume nasce nell’ambito di un accordo di collaborazione stipulato tra il Ministero dell’Ambiente e della Tutela del Territorio e del Mare (MATTM) e il Consiglio Nazionale delle Ricerche, Dipartimento di Scienze Bio-Agroalimentari (CNR-DiSBA) e fornisce una panoramica sulla normativa internazionale in materia di Organismi Geneticamente Modificati (OGM) e dimostrare come il quadro normativo venga costantemente adeguato al continuo sviluppo scientifico nel campo delle biotecnologie
A new mutant of Arabidopsis named rha1 is characterized and the gene involved cloned. In roots, t... more A new mutant of Arabidopsis named rha1 is characterized and the gene involved cloned. In roots, the mutant shows minimal right-handed slanting, reduced gravitropic response, notable resistance to 2,4-D, but scarce resistance to IAA and NAA. The roots also show a clear resistance to the auxin transport inhibitors TIBA and NPA, and to ethylene. Other characteristics are a reduced number of lateral roots and reduced size of shoot and root in the seedlings. The gene, cloned through TAIL-PCR, was found to be a heat-shock factor that maps on chromosome 5, close to and above the RFLP marker m61. The rha1 structure, mRNA, and translation product are reported. Since, so far, no other gravitropic mutant has been described as mutated in a heat-shock factor, rha1 belongs to a new group of mutants disturbed in slanting, gravitropism, and auxin physiology. As shown through the RT-PCR analyses of its expression, the gene retains the function connected with heat shock. If the characteristics connected with auxin physiology are considered, however, it is also likely that the gene, as a transcription factor, could be involved in root circumnutation, gravitropic response, and hormonal control of differentiation. Since GUS staining under the gene promoter was localized mainly in the mature tissues, rha1 does not seem to be involved in the first steps of gravitropism, but is rather related to the general response to auxin. The alterations in slanting (mainly due to reduced chiral circumnutation) and gravitropism lead to the supposition that the two processes may have, at least in part, common origins.
Objectives According to international observations, the incidence of clinical autopsies is declin... more Objectives According to international observations, the incidence of clinical autopsies is declining worldwide, plummeting below 5% in the USA and many European countries. It is an unfavourable trend as, in 7%-12% of cases, recent clinicopathological studies found discrepancies that might have changed the therapy or the outcome if known premortem. As previous large-scale observations have examined varied patient populations, we aimed to focus on the differences between the clinical and pathological diagnostic findings in only patients who had a stroke. Material and methods We assessed the postmortem non-neuropathological and neuropathological findings of 534 consecutive patients who had a stroke who passed away. Systemic neoplasms, pneumonias, thromboembolisms and haemorrhagic transformations revealed only by autopsy were considered severe abnormalities; in addition, benign abnormalities important from an educational or scientific point of view were also recorded. Results In 26 of the 534 cases (4.9%), the presence of systemic neoplasms had already been confirmed in the clinical stage; however, 8 (1.5%) malignant tumours were only detected during autopsy. Also, 80 (15%) thromboembolic events, 73 (13.6%) pneumonias and 66 (18%) haemorrhagic transformations were only diagnosed at autopsy. Longer hospital stay (from admission to death) resulted in fewer discrepancies between clinical and autopsy diagnosis of thromboembolic events and pneumonias (p<0.01). In 169 cases, benign findings were detected. Conclusions While the type of acute stroke is reliably diagnosed with imaging techniques, postmortem autopsies are also important in patients who had a stroke as autopsies may reveal clinically silent diseases (eg, tumour), and contribute to knowing the actual incidence of strokerelated thromboembolic and pneumonia complications.
In Saccharomyces cerevisiae, Adr1 is a zinc-finger transcription factor involved in the transcrip... more In Saccharomyces cerevisiae, Adr1 is a zinc-finger transcription factor involved in the transcriptional activation of ADH2. Deletion of KlADR1, its putative ortholog in Kluyveromyces lactis, led to reduced growth in glycerol, oleate and yeast extract-peptone medium suggesting, as in S. cerevisiae, its requirement for glycerol, fatty acid and nitrogen utilization. Moreover, growth comparison on yeast extract and peptone plates showed in K. lactis a KlAdr1-dependent growth trait not present in S. cerevisiae, indicating different metabolic roles of the two factors in their environmental niches. KlADR1 is required for growth under respiratory and fermentative conditions like KlADH, alcohol dehydrogenase genes necessary for metabolic adaptation during the growth transition. Using in-gel native alcohol dehydrogenase assay, we showed that this factor affected the Adh pattern by altering the balance between these activities. Since the activity most affected by KlAdr1 is KlAdh3, a deletion analysis of the KlADH3 promoter allowed the isolation of a DNA fragment through which KlAdr1 modulated its expression. The expression of the KlADR1-GFP gene allowed the intracellular localization of the factor in K. lactis and S. cerevisiae, suggesting in the two yeasts a common mechanism of KlAdr1 translocation under fermentative and respiratory conditions. Finally, the chimeric Kl/ScADR1 gene encoding the zincfinger domains of KlAdr1 fused to the transactivating domains of the S. cerevisiae factor activated in Scadr1D the transcription of ADH2 in a ScAdr1-dependent fashion.
Journal of Biological Research - Bollettino della Società Italiana di Biologia Sperimentale, 2011
ABSTRACT The effect of microgravity on the expression of genes for tubulin, stress and aging in A... more ABSTRACT The effect of microgravity on the expression of genes for tubulin, stress and aging in Arabidopsis seedlings from wild-type, and the auxinic mutants aux 1 and eir/pin2 is reported. Simulated microgravity was produced through the Random Positioning Machine (RPM). The results showed that the tubulin genes TUA4, TUA6 and TUB2, in plants subjected to μg, showed a peak of expression at 3h in the wild-type, whereas in the mutants it was delayed to 6h. The microgravity treatment tested on the expression of stress genes FeSOD1 and CAT3 showed only a significant increase of senescence SAG12 showed increased expression in the wild-type starting at 3h, whereas in the mutant a significant increase was seen only at 24h. From the collected data we conclude that auxin transport and action should be involved in tubulin synthesis, stress, and the senescence process.
The increasing use of cobalt oxide (Co3 O4 ) nanoparticles (NPs) in several applications and the ... more The increasing use of cobalt oxide (Co3 O4 ) nanoparticles (NPs) in several applications and the suggested genotoxic potential of Co-oxide highlight the importance of evaluating Co3 O4 NPs toxicity. Cyto-genotoxic and inflammatory effects induced by Co3 O4 NPs were investigated in human alveolar (A549), and bronchial (BEAS-2B) cells exposed to 1-40 µg ml(-1) . The physicochemical properties of tested NPs were analysed by transmission electron microscopy (TEM) and dynamic light scattering (DLS). Cytotoxicity was studied to analyze cell viability (WST1 test) and membrane damage (LDH assay), direct/oxidative DNA damage was assessed by the Formamido-pyrimidine glycosylase (Fpg)-modified comet assay and inflammation by interleukin (IL)-6, IL-8 and tumor necrosis factor-alpha (TNF-α) release (ELISA). In A549 cells, no cytotoxicity was found, whereas BEAS-2B cells showed a viability reduction at 40 µg ml(-1) and early membrane damage at 1, 5 and 40 µg ml-1. In A549 cells, direct and oxidat...
A new Arabidopsis mutant is characterized (rha1) that shows, in the roots, reduced right-handed s... more A new Arabidopsis mutant is characterized (rha1) that shows, in the roots, reduced right-handed slanting, reduced gravitropism and resistance to 2,4-D, TIBA, NPA and ethylene. It also shows reduced length in the shoot and root, reduced number of lateral roots and shorter siliques. The gene was cloned through TAIL-PCR and resulted in a HSF. Because none of the known gravitropic and auxinic mutants result from damage in a HSF, rha1 seems to belong to a new class of this group of mutants. Quantitative PCR analysis showed that the expression of the gene is increased by heat and cold shock, and by presence of 2,4-D in the media. Study of the expression through the GUS reporter gene revealed increased expression in clinostated and gravistimulated plants, but only in adult tissues, and not in the apical meristems of shoots and roots.
Occupational exposure of granite workers is well known to cause lung impairment and silicosis. To... more Occupational exposure of granite workers is well known to cause lung impairment and silicosis. Toxicological profiles of different size particles of granite dust, however, are not yet understood. Present evaluation of micro- and nano-particles of granite dust as on human lung fibroblast cells IMR-90, revealed that their toxic effects were dose-dependent, and nanoparticles in general were more toxic. In this study we first demonstrated that nanoparticles caused oxidative stress, inflammatory response and genotoxicity, as seen by nearly 2 fold induction of ROS and LPO, mRNA levels of TNF-α and IL-1β, and induction in micronuclei formation. All these were significantly higher when compared with the effect of micro particles. Thus, the study suggests that separate health safety standards would be required for granite particles of different sizes.
larger objects. Taking the specific surface, "LOELs" of nano-objects (>70 m 2 /g) differ by a fac... more larger objects. Taking the specific surface, "LOELs" of nano-objects (>70 m 2 /g) differ by a factor of 5. Also the scope of the studies differs regarding the investigated effects or the related time points. Effects in lung are, however, investigated in the majority of studies so that some frequent effect like neutrophil number, total protein and LDH content in BALF, lung weight or infiltration were analyzed in more detail. Lung weight turned out as sensitive parameter for lung toxicity, although some weight gain is caused by particle burden under overload conditions. The PaFtox database offers the opportunity to investigate the available toxicological data of particles systematically and structured. This database is a nice tool e.g. for identifying physicochemical properties related to specific toxic effect e.g. to cancer.
Over the last fifteen years, an increasing number of plant scientists have become interested in t... more Over the last fifteen years, an increasing number of plant scientists have become interested in the Arabidopsis root growth pattern, that is produced on the surface of an agar plate, inclined from the vertical. In this situation, the roots wave intensely and slant preferentially towards one side, showing torsions in the epidermal cell files alternately right-and left handed. In addition, the pattern switches to the formation of large or strict coils when the plate is set horizontally. After this finding, different hypotheses were advanced attempting to explain the forces that shape these patterns. These basically appear to be gravitropism, circumnutation and negative thigmotropism. With regard to the symmetry, the coils and the slanting in the wild-type are essentially righthanded, but mutants were also reported which show a left-handed symmetry, while some do not show a regular growth pattern at all. This review article discusses the earlier as well as the most recent findings on the topic, and investigates the possibility of describing the different mechanisms shaping the root growth patterns via unifying hypothesis.
Thanks are given to the Italian National Research Council (CNR), special issue editor Dr. J. Z. K... more Thanks are given to the Italian National Research Council (CNR), special issue editor Dr. J. Z. Kiss who invited us to write the review, Beth Hazen for editing the English, Valerio Muzzini for handling the fi gures, and colleagues for useful suggestions and discussion.
KlNDE1 and KlNDI1 code for two inner mitochondrial membrane transdehydrogenases involved in the m... more KlNDE1 and KlNDI1 code for two inner mitochondrial membrane transdehydrogenases involved in the maintenance of the intracellular NAD(P)H redox balance. The function of these genes during the utilization of fermentative and respiratory carbon sources was studied. During growth in glucose, deletion of KlNDE1 and KlNDI1 led to an altered kinetic of ethanol and glycerol accumulation compared with the wild type; in addition, KlndiDelta was unable to grow in respiratory substrates. Northern analysis and GFP-fusion experiments showed that KlNDE1 and KlNDI1 regulate the expression of KlGUT2, a component of the glycerol-3-phosphate shuttle. Moreover, both genes seem to be involved in the biogenesis of the mitochondrial tubular network.
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