title: Nitric oxide and hydrogen peroxide involvement during programmed cell death of Sechium edule nucellus.
abstract: The nucellus is a maternal tissue that feeds the developing embryo and the secondary endosperm. During seed development the cells of the nucellus suffer a degenerative process early after fertilization as the cellular endosperm expands and accumulates reserves. Nucellar cell degeneration has been characterized as a form of developmentally programmed cell death (PCD). In this work we show that nucellus PCD is accompanied by a considerable production of both nitric oxide and hydrogen peroxide (NO and H(2)O(2)). Interestingly, each of the two molecules is able to induce the production of the other and to cause cell death when applied to a living nucellus. We show that the induced cell death has features of a PCD, accompanied by profound changes in the morphology of the nuclei and by a massive degradation of nuclear DNA. Moreover, we report that NO and H(2)O(2) cause an induction of caspase-like proteases previously characterized in physiological nucellar PCD.
authors.affiliation: Department of Biology, University of Pisa, 56126 Pisa, Italy. llombardi@biologia.unipi.it
authors.forename: Lara
authors.initials: L
authors.lastname: Lombardi
authors.forename: Nello
authors.initials: N
authors.lastname: Ceccarelli
authors.forename: Piero
authors.initials: P
authors.lastname: Picciarelli
authors.forename: Carlo
authors.initials: C
authors.lastname: Sorce
authors.forename: Roberto
authors.initials: R
authors.lastname: Lorenzi
mesh_terms: D017209:Apoptosis; D002467:Cell Nucleus / Q000502:physiology; D019662:Cucurbitaceae / Q000196:embryology* / Q000378:metabolism; D053938:DNA Fragmentation; D018744:DNA, Plant / Q000032:analysis; D006861:Hydrogen Peroxide / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism*; D010447:Peptide Hydrolases / Q000378:metabolism; D012639:Seeds / Q000254:growth & development* / Q000378:metabolism / Q000502:physiology
chemical_list: D018744:DNA, Plant; D009569:Nitric Oxide; D006861:Hydrogen Peroxide; D010447:Peptide Hydrolases