Death of embryos from 2300-year-old quinoa seeds found in an archaeological site

AGUSTÍN SANGUINETTI; SARA MALDONADO; CATALINA TERESA MICHIELI; HERNÁN PABLO BURRIEZA; HÉCTOR DANIEL BERTERO

PLANT SCIENCE

ELSEVIER IRELAND LTD

Lugar: Amsterdam; Año: 2016 vol. 253 p. 107 - 117

0168-9452

tIn the 1970s, during excavations at Los Morrillos, San Juan, Argentina, quinoa seeds were found withinancient pumpkin crocks protected from the light and high temperatures, and preserved in the verydry conditions of the region. The radiocarbon dates confirmed the age of these seeds at around 2300years. Sectioning of some of these seeds showed reddish-brown embryos, different from the whiteembryos of recently harvested quinoa seeds. The ancient seeds did not germinate. The structure of theembryo cells was examined using light and transmission electron microscopy; proteins were analyzed byelectrophoresis followed by Coomassie blue and periodic acid Schiff staining and fatty acids by gas chro-matography. The state of nuclear DNA was investigated by TUNEL assay, DAPI staining, ladder agaroseelectrophoresis and flow cytometry. Results suggest that, although the embryo tissues contained verylow water content, death occurred by a cell death program in which heterochromatin density was dra-matically reduced, total DNA was degraded into small fragments of less than 500 bp, and some proteinswere modified by non-enzymatic glycation, generating Maillard products. Polyunsaturated fatty acidsdecreased and became fragmented, which could be attributable to the extensive oxidation of the mostsensitive species (linolenic and linoleic acids) and associated with a collapse of lipid bodies