title: Programmed cell death during quinoa perisperm development.
abstract: At seed maturity, quinoa (Chenopodium quinoa Willd.) perisperm consists of uniform, non-living, thin-walled cells full of starch grains. The objective of the present study was to study quinoa perisperm development and describe the programme of cell death that affects the entire tissue. A number of parameters typically measured during programmed cell death (PCD), such as cellular morphological changes in nuclei and cytoplasm, endoreduplication, DNA fragmentation, and the participation of nucleases and caspase-like proteases in nucleus dismantling, were evaluated; morphological changes in cytoplasm included subcellular aspects related to starch accumulation. This study proved that, following fertilization, the perisperm of quinoa simultaneously accumulates storage reserves and degenerates, both processes mediated by a programme of developmentally controlled cell death. The novel findings regarding perisperm development provide a starting point for further research in the Amaranthaceae genera, such as comparing seeds with and without perisperm, and specifying phylogeny and evolution within this taxon. Wherever possible and appropriate, differences between quinoa perisperm and grass starchy endosperm--a morphologically and functionally similar, although genetically different tissue--were highlighted and discussed.
authors.affiliation: Departamento de Biodiversidad y Biología Experimenta, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Intendente Guiraldes 2160, Pab. 2, Ciudad Universitaria, C1428EGA, Argentina.
authors.forename: María Paula
authors.initials: MP
authors.lastname: López-Fernández
authors.forename: Sara
authors.initials: S
authors.lastname: Maldonado
mesh_terms: D017209:Apoptosis / Q000235:genetics / Q000502:physiology; D027465:Chenopodium quinoa / Q000166:cytology* / Q000235:genetics / Q000378:metabolism*; D053938:DNA Fragmentation; D010447:Peptide Hydrolases / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D012639:Seeds / Q000166:cytology* / Q000235:genetics / Q000378:metabolism*
chemical_list: D010940:Plant Proteins; D010447:Peptide Hydrolases
keywords: Amaranthaceae; DNA fragmentation; TUNEL.; basal body; caspase-like protease; endoreduplication; nucleases; perisperm; programmed cell death (PCD); quinoa; starch accumulation