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Titolo:
DNA fragmentation and nuclear degradation during programmed cell death in the suspensor and endosperm of Vicia faba
Autore:
Wredle, U; Walles, B; Hakman, I;
Indirizzi:
Stockholm Univ, Dept Bot, SE-10691 Stockholm, Sweden Stockholm Univ Stockholm Sweden SE-10691 Bot, SE-10691 Stockholm, Sweden
Titolo Testata:
INTERNATIONAL JOURNAL OF PLANT SCIENCES
fascicolo: 5, volume: 162, anno: 2001,
pagine: 1053 - 1063
SICI:
1058-5893(200109)162:5<1053:DFANDD>2.0.ZU;2-2
Fonte:
ISI
Lingua:
ENG
Soggetto:
HYPERSENSITIVE RESPONSE; TRACHEARY ELEMENTS; FUNCTIONAL-ANATOMY; MAIZE ENDOSPERM; ABSCISIC-ACID; PLANTS; APOPTOSIS; ARABIDOPSIS; MECHANISMS; BARLEY;
Keywords:
DNA fragmentation; endosperm; nucleus; programmed cell death; suspensor;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Agriculture,Biology & Environmental Sciences
Citazioni:
47
Recensione:
Indirizzi per estratti:
Indirizzo: Wredle, U Stockholm Univ, Dept Bot, SE-10691 Stockholm, Sweden Stockholm Univ Stockholm Sweden SE-10691 691 Stockholm, Sweden
Citazione:
U. Wredle et al., "DNA fragmentation and nuclear degradation during programmed cell death in the suspensor and endosperm of Vicia faba", INT J PL SC, 162(5), 2001, pp. 1053-1063

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 tothe nuclear periphery as electron-dense areas. The nucleolus will keep itsround and condensed shape for some time before expanding into an irregularbody. 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 thatboth the suspensor and the endosperm go through PCD processes, but the pathways leading to dismantling of the cells do not follow identical routes inthe two tissues. DNA fragmentation occurs in intact cells and within an intact nuclear envelope and not in cells that already are damaged. PCD in theendosperm 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.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 21/09/20 alle ore 12:46:07