title: Formation of archegonium chamber is associated with nucellar-cell programmed cell death in Ginkgo biloba.
abstract: The archegonium chamber in Ginkgo biloba L. is a pathway for spermatozoids swimming towards the archegonium for fertilization. The objective of this study was to elucidate the mechanism of archegonium chamber formation. The terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay and DNA ladder demonstrated that the nucellar cell death, coordinated with the archegonium chamber formation, was a process of programmed cell death. Cytochemical localization of Ca(2+) in these nucellar cells was determined by means of in situ precipitation with potassium pyroantimonate and electron microscopic visualization, in order to study the relation between Ca(2+) and programmed cell death. The results showed an early uptake of the mitochondrial calcium particles in the nucellar cells undergoing programmed cell death. Together with other dynamic changes in Ca(2+) subcellular distribution, this indicates that Ca(2+) may play a role in the regulation of mitochondria-mediated programmed events in the nucellar cells.
authors.affiliation: School of Pharmaceutical Sciences, Peking University, Beijing. dhl@water.pku.edu.cn
authors.forename: Da-Hui
authors.initials: DH
authors.lastname: Li
authors.forename: Xiong
authors.initials: X
authors.lastname: Yang
authors.forename: Ke-Ming
authors.initials: KM
authors.lastname: Cui
mesh_terms: D017209:Apoptosis; D002118:Calcium / Q000378:metabolism; D018744:DNA, Plant; D020441:Ginkgo biloba / Q000166:cytology* / Q000254:growth & development / Q000648:ultrastructure; D020287:In Situ Nick-End Labeling; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D008928:Mitochondria / Q000378:metabolism / Q000648:ultrastructure; D018514:Plant Structures / Q000166:cytology; D011058:Pollen / Q000648:ultrastructure
chemical_list: D018744:DNA, Plant; D002118:Calcium