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Ruffini M Castiglione - One of the best experts on this subject based on the ideXlab platform.

  • aluminum effects on embryo suspensor polytene chromosomes of Phaseolus coccineus l
    Plant Biosystems, 2017
    Co-Authors: Gianni Bartoli, Sanita L Di Toppi, Andrea Andreucci, Ruffini M Castiglione
    Abstract:

    AbstractAluminum (Al) represents a widespread environmental pollutant, with severe toxic impacts on plants. In this study, we documented for the first time the structural and functional responses induced by two concentrations of AlCl3 (10−2 M and 10−1 M) in the polytene chromosomes that characterize the chromatin organization in the embryo suspensor cells of Phaseolus coccineus. Polytene chromosomes showed signs of dose-dependent genotoxicity following AlCl3 treatments with a significant increase in both chromatin stickiness and chromatin fragmentation. Polytene chromosomes specifically reacted to AlCl3 also in terms of DNA and RNA puffing activity: with respect to the control, the treatments promoted ex-novo and/or inhibited puff formation along chromosome arms, suggesting a fine modulation of the differential genome activity in response to the treatments. The nuclei of suspensors from control and treated seeds showed nucleoli mainly arranged by more than one NOR-bearing chromosome. In addition, AlCl3 tr...

Roberto Lorenzi - One of the best experts on this subject based on the ideXlab platform.

  • DNA degradation during programmed cell death in Phaseolus coccineus suspensor.
    Plant Physiology and Biochemistry, 2007
    Co-Authors: Lara Lombardi, Piero Picciarelli, Nello Ceccarelli, Roberto Lorenzi
    Abstract:

    The suspensor of Phaseolus coccineus L. degenerates at the cotyledonary stage of embryogenesis when it is no longer necessary for continued embryonic development; this degeneration is considered to be a typical example of the so-called developmental programmed cell death (PCD) in plants. The presence of specific hallmarks of PCD as it occurs during the degeneration of P. coccineus suspensor was investigated in the current study. By using the TUNEL assay and electrophoretic analysis, we found evidence of nuclear DNA degradation, a known feature of PCD, in the endosperm and degenerating suspensors. Degeneration of the suspensor begins after degeneration in the endosperm and it starts in the neck region, spreading basipetally towards the knob. We conclude from this study that suspensor degeneration in P. coccineus occurs by means of PCD and displays typical hallmarks of PCD, such as DNA fragmentation. PCD in the suspensor is a highly asynchronous process, originating first in the neck cells and subsequently spreading to the basal cells.

  • Caspase-like proteases involvement in programmed cell death of Phaseolus coccineus suspensor
    Plant Science, 2007
    Co-Authors: Lara Lombardi, Piero Picciarelli, Nello Ceccarelli, Roberto Lorenzi
    Abstract:

    The suspensor of Phaseolus coccineus L. is a short-living tissue, which begins to degenerate at the early cotyledon stage of embryogenesis when it has become no more necessary for further embryo development. The degeneration of terminally differentiated suspensor is considered one of the most typical examples of developmental programmed cell death in plants. We report the occurrence of some hallmarks of animal apoptosis such a leakage of cytochrome C from the mitochondria to the cytosol and an induction of caspase-like proteases, which are sensitive to pH and to specific inhibitors but not affected by generic protease inhibitors.

Gianni Bartoli - One of the best experts on this subject based on the ideXlab platform.

  • aluminum effects on embryo suspensor polytene chromosomes of Phaseolus coccineus l
    Plant Biosystems, 2017
    Co-Authors: Gianni Bartoli, Sanita L Di Toppi, Andrea Andreucci, Ruffini M Castiglione
    Abstract:

    AbstractAluminum (Al) represents a widespread environmental pollutant, with severe toxic impacts on plants. In this study, we documented for the first time the structural and functional responses induced by two concentrations of AlCl3 (10−2 M and 10−1 M) in the polytene chromosomes that characterize the chromatin organization in the embryo suspensor cells of Phaseolus coccineus. Polytene chromosomes showed signs of dose-dependent genotoxicity following AlCl3 treatments with a significant increase in both chromatin stickiness and chromatin fragmentation. Polytene chromosomes specifically reacted to AlCl3 also in terms of DNA and RNA puffing activity: with respect to the control, the treatments promoted ex-novo and/or inhibited puff formation along chromosome arms, suggesting a fine modulation of the differential genome activity in response to the treatments. The nuclei of suspensors from control and treated seeds showed nucleoli mainly arranged by more than one NOR-bearing chromosome. In addition, AlCl3 tr...

Piero Picciarelli - One of the best experts on this subject based on the ideXlab platform.

  • DNA degradation during programmed cell death in Phaseolus coccineus suspensor.
    Plant Physiology and Biochemistry, 2007
    Co-Authors: Lara Lombardi, Piero Picciarelli, Nello Ceccarelli, Roberto Lorenzi
    Abstract:

    The suspensor of Phaseolus coccineus L. degenerates at the cotyledonary stage of embryogenesis when it is no longer necessary for continued embryonic development; this degeneration is considered to be a typical example of the so-called developmental programmed cell death (PCD) in plants. The presence of specific hallmarks of PCD as it occurs during the degeneration of P. coccineus suspensor was investigated in the current study. By using the TUNEL assay and electrophoretic analysis, we found evidence of nuclear DNA degradation, a known feature of PCD, in the endosperm and degenerating suspensors. Degeneration of the suspensor begins after degeneration in the endosperm and it starts in the neck region, spreading basipetally towards the knob. We conclude from this study that suspensor degeneration in P. coccineus occurs by means of PCD and displays typical hallmarks of PCD, such as DNA fragmentation. PCD in the suspensor is a highly asynchronous process, originating first in the neck cells and subsequently spreading to the basal cells.

  • Caspase-like proteases involvement in programmed cell death of Phaseolus coccineus suspensor
    Plant Science, 2007
    Co-Authors: Lara Lombardi, Piero Picciarelli, Nello Ceccarelli, Roberto Lorenzi
    Abstract:

    The suspensor of Phaseolus coccineus L. is a short-living tissue, which begins to degenerate at the early cotyledon stage of embryogenesis when it has become no more necessary for further embryo development. The degeneration of terminally differentiated suspensor is considered one of the most typical examples of developmental programmed cell death in plants. We report the occurrence of some hallmarks of animal apoptosis such a leakage of cytochrome C from the mitochondria to the cytosol and an induction of caspase-like proteases, which are sensitive to pH and to specific inhibitors but not affected by generic protease inhibitors.

  • Endogenous auxins and embryogenesis in Phaseolus coccineus
    Australian Journal of Plant Physiology, 2001
    Co-Authors: Piero Picciarelli, Nello Ceccarelli, Fernando Paolicchi, Gianni Calistri
    Abstract:

    The occurrence and the dynamics of free and bound indole-3-acetic acid (IAA) in different parts of Phaseolus coccineus L. seeds were investigated at various developmental stages. Results show that free and bound IAA content in the single seed parts is quite different, and changes with different patterns during seed growth. The highest concentration of total IAA was found in early-heart stage embryos, while the total IAA concentration in the suspensor at early-heart stage is much lower than in the embryos, and remains almost constant in the later stages. Integuments have an intermediate content at the first two developmental stages, while showing the highest concentration of total IAA at the cotyledonary stage. Concerning the percentage of free IAA in relation to the total pool, we found that in the embryos free IAA accounts for 26-28% in the first two stages then increases up to 44% at the cotyledonary stage. In suspensors, the percentage of free IAA is much higher (90%) in all developmental stages. We discuss the idea that the different level of auxin between embryos and the suspensor might play an important role in the establishment of embryo polarity.

  • Gibberellins in suspensor, embryo and integument from very young seeds of Phaseolus coccineus L.
    Plant Growth Regulation, 1994
    Co-Authors: Piero Picciarelli, Nello Ceccarelli, Alberto Piaggesi, Lorenzo Guglielminetti, Amedeo Alpi
    Abstract:

    Endogenous gibberellins (GAs) were extracted from suspensor, embryo and integument of very young seeds of Phaseolus coccineus L. and detected by combined gas chromatography-mass spectrometry (GC-MS). Results show the presence of one C20-GA, GA44 and five C19-GAs in the suspensor: GA1, GA4, GA5, GA6 and GA8, and four C19-GAs in the integument: GA1, GA5, GA6 and GA8. Only traces of GA1 and GA5 were identified in the embryo. A compound structurally related to GAs was identified as tetrahydroxy-Kauranoic acid in suspensor, integument and, only in trace amounts, in the embryo.

Nello Ceccarelli - One of the best experts on this subject based on the ideXlab platform.

  • DNA degradation during programmed cell death in Phaseolus coccineus suspensor.
    Plant Physiology and Biochemistry, 2007
    Co-Authors: Lara Lombardi, Piero Picciarelli, Nello Ceccarelli, Roberto Lorenzi
    Abstract:

    The suspensor of Phaseolus coccineus L. degenerates at the cotyledonary stage of embryogenesis when it is no longer necessary for continued embryonic development; this degeneration is considered to be a typical example of the so-called developmental programmed cell death (PCD) in plants. The presence of specific hallmarks of PCD as it occurs during the degeneration of P. coccineus suspensor was investigated in the current study. By using the TUNEL assay and electrophoretic analysis, we found evidence of nuclear DNA degradation, a known feature of PCD, in the endosperm and degenerating suspensors. Degeneration of the suspensor begins after degeneration in the endosperm and it starts in the neck region, spreading basipetally towards the knob. We conclude from this study that suspensor degeneration in P. coccineus occurs by means of PCD and displays typical hallmarks of PCD, such as DNA fragmentation. PCD in the suspensor is a highly asynchronous process, originating first in the neck cells and subsequently spreading to the basal cells.

  • Caspase-like proteases involvement in programmed cell death of Phaseolus coccineus suspensor
    Plant Science, 2007
    Co-Authors: Lara Lombardi, Piero Picciarelli, Nello Ceccarelli, Roberto Lorenzi
    Abstract:

    The suspensor of Phaseolus coccineus L. is a short-living tissue, which begins to degenerate at the early cotyledon stage of embryogenesis when it has become no more necessary for further embryo development. The degeneration of terminally differentiated suspensor is considered one of the most typical examples of developmental programmed cell death in plants. We report the occurrence of some hallmarks of animal apoptosis such a leakage of cytochrome C from the mitochondria to the cytosol and an induction of caspase-like proteases, which are sensitive to pH and to specific inhibitors but not affected by generic protease inhibitors.

  • Endogenous auxins and embryogenesis in Phaseolus coccineus
    Australian Journal of Plant Physiology, 2001
    Co-Authors: Piero Picciarelli, Nello Ceccarelli, Fernando Paolicchi, Gianni Calistri
    Abstract:

    The occurrence and the dynamics of free and bound indole-3-acetic acid (IAA) in different parts of Phaseolus coccineus L. seeds were investigated at various developmental stages. Results show that free and bound IAA content in the single seed parts is quite different, and changes with different patterns during seed growth. The highest concentration of total IAA was found in early-heart stage embryos, while the total IAA concentration in the suspensor at early-heart stage is much lower than in the embryos, and remains almost constant in the later stages. Integuments have an intermediate content at the first two developmental stages, while showing the highest concentration of total IAA at the cotyledonary stage. Concerning the percentage of free IAA in relation to the total pool, we found that in the embryos free IAA accounts for 26-28% in the first two stages then increases up to 44% at the cotyledonary stage. In suspensors, the percentage of free IAA is much higher (90%) in all developmental stages. We discuss the idea that the different level of auxin between embryos and the suspensor might play an important role in the establishment of embryo polarity.

  • Gibberellins in suspensor, embryo and integument from very young seeds of Phaseolus coccineus L.
    Plant Growth Regulation, 1994
    Co-Authors: Piero Picciarelli, Nello Ceccarelli, Alberto Piaggesi, Lorenzo Guglielminetti, Amedeo Alpi
    Abstract:

    Endogenous gibberellins (GAs) were extracted from suspensor, embryo and integument of very young seeds of Phaseolus coccineus L. and detected by combined gas chromatography-mass spectrometry (GC-MS). Results show the presence of one C20-GA, GA44 and five C19-GAs in the suspensor: GA1, GA4, GA5, GA6 and GA8, and four C19-GAs in the integument: GA1, GA5, GA6 and GA8. Only traces of GA1 and GA5 were identified in the embryo. A compound structurally related to GAs was identified as tetrahydroxy-Kauranoic acid in suspensor, integument and, only in trace amounts, in the embryo.