Abstract
In Vicia faba, both the suspensor and the endosperm are short‐lived structures. The aim of this work was to elucidate and compare programmed cell death (PCD) mechanisms in these two ephemeral tissues. To achieve this, we used the TdT‐mediated dUDP fluorescent (FITC) nick end labeling (TUNEL) technique to trace DNA fragmentation and transmission electron microscopy to follow chromosomal and nuclear degradation. The TUNEL experiments demonstrated DNA fragmentation in the endosperm nuclei 13 d after pollination (dap) and in the suspensor at 14 dap. However, the ultrastructural studies did not show any chromosomal degradation in the nuclei of the suspensor or endosperm until 17 dap, indicating that the DNA fragmentation is an initial step in the PCD pathway. We have further documented fundamental differences in the degeneration process of the nuclei of the two tissues. In the suspensor the heterochromatin becomes more condensed during degeneration and disperses to the nuclear periphery as electron‐dense areas. The nucleolus will keep its round and condensed shape for some time before expanding into an irregular body. In the endosperm the heterochromatin is more like a network throughout the nucleus, and the nucleolus will eventually split into pieces scattered inside the heterochromatin. Internal vesicle‐like structures appear in the nuclei of the suspensor at 11–13 dap. However, they might have a communicative function not necessarily related to the cell death. We conclude that both the suspensor and the endosperm go through PCD processes, but the pathways leading to dismantling of the cells do not follow identical routes in the two tissues. DNA fragmentation occurs in intact cells and within an intact nuclear envelope and not in cells that already are damaged. PCD in the endosperm precedes PCD in the suspensor, indicating that they might receive different signals or that the signal triggers different internal death programs in the two tissues.
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 12
Claim · model-written summary
DNA fragmentation appeared in endosperm nuclei at 13 days after pollination.
- Taxon
- Vicia faba
Vicia fabat0 - Organ / stage
- endosperm nucleie0
- Outcome
- DNA fragmentatione0
- Value
- 13 d after pollination (dap)e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“DNA fragmentation in the endosperm nuclei 13 d after pollination (dap)”
t0“Vicia faba”
Claim · model-written summary
DNA fragmentation appeared in the suspensor at 14 days after pollination.
- Taxon
- Vicia fabaVicia fabat0
- Organ / stage
- suspensore0
- Outcome
- in the suspensor at 14 dape0
- Value
- 14 dape0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“in the suspensor at 14 dap”
t0“Vicia faba”
Claim · model-written summary
Chromosomal degradation was absent in suspensor and endosperm nuclei until 17 days after pollination.
- Taxon
- Vicia fabaVicia fabat0
- Organ / stage
- nuclei of the suspensor or endosperme0
- Outcome
- chromosomal degradatione0
- Direction
- did not showe0
- Value
- 17 dape0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“did not show any chromosomal degradation in the nuclei of the suspensor or endosperm until 17 dap”
t0“Vicia faba”
Claim · model-written summary
The authors interpret DNA fragmentation as an initial step in programmed cell death.
- Taxon
- Vicia fabaVicia fabat0
- Outcome
- DNA fragmentatione0
- Qualifier
- initial step in the PCD pathwaye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“DNA fragmentation is an initial step in the PCD pathway”
t0“Vicia faba”
Claim · model-written summary
Suspensor heterochromatin becomes more condensed and moves to the nuclear periphery during degeneration.
- Taxon
- Vicia fabaVicia fabat0
- Organ / stage
- suspensore0
- Outcome
- heterochromatine0
- Direction
- more condensede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In the suspensor the heterochromatin becomes more condensed during degeneration and disperses to the nuclear periphery as electron‐dense areas”
t0“Vicia faba”
Claim · model-written summary
The suspensor nucleolus retains a round, condensed shape before expanding irregularly.
- Taxon
- Vicia fabaVicia fabat0
- Organ / stage
- suspensore1
- Outcome
- nucleoluse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The nucleolus will keep its round and condensed shape for some time before expanding into an irregular body”
e1“in the suspensor at 14 dap”
t0“Vicia faba”
Claim · model-written summary
Endosperm heterochromatin forms a network across the nucleus.
- Taxon
- Vicia fabaVicia fabat0
- Organ / stage
- endosperme0
- Outcome
- heterochromatine0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In the endosperm the heterochromatin is more like a network throughout the nucleus”
t0“Vicia faba”
Claim · model-written summary
The endosperm nucleolus eventually splits into pieces within the heterochromatin.
- Taxon
- Vicia fabaVicia fabat0
- Organ / stage
- endosperme1
- Outcome
- nucleoluse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the nucleolus will eventually split into pieces scattered inside the heterochromatin”
e1“DNA fragmentation in the endosperm nuclei 13 d after pollination (dap)”
t0“Vicia faba”
Claim · model-written summary
Vesicle-like structures appeared in suspensor nuclei at 11–13 days after pollination.
- Taxon
- Vicia fabaVicia fabat0
- Organ / stage
- nuclei of the suspensore0
- Outcome
- Internal vesicle‐like structurese0
- Value
- 11–13 dape0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Internal vesicle‐like structures appear in the nuclei of the suspensor at 11–13 dap”
t0“Vicia faba”
Claim · model-written summary
DNA fragmentation occurs in intact cells and intact nuclear envelopes.
- Taxon
- Vicia fabaVicia fabat0
- Outcome
- DNA fragmentatione0
- Qualifier
- intact cells and within an intact nuclear envelopee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“DNA fragmentation occurs in intact cells and within an intact nuclear envelope and not in cells that already are damaged”
t0“Vicia faba”
Claim · model-written summary
Endosperm programmed cell death precedes suspensor programmed cell death.
- Taxon
- Vicia fabaVicia fabat0
- Organ / stage
- endosperme0
- Outcome
- PCDe0
- Direction
- precedese0
- Comparator
- suspensore0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“PCD in the endosperm precedes PCD in the suspensor”
t0“Vicia faba”
Claim · model-written summary
The two tissues follow different routes of programmed cell death.
- Taxon
- Vicia fabaVicia fabat0
- Outcome
- pathways leading to dismantling of the cellse0
- Qualifier
- do not follow identical routese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the pathways leading to dismantling of the cells do not follow identical routes in the two tissues”
t0“Vicia faba”