Spatial and temporal regulation of DNA fragmentation in the aleurone of germinating barley

• Published in: Journal of experimental botany Vol. 49; no. 325; pp. 1293 - 1301
• Main Authors: Wang, Mei, Oppedijk, Berry J., Caspers, Martien P.M., Lamers, Gerda E.M., Boot, Marit J., Geerlings, Dave N.G., Bakhuizen, Bob, Meijer, Annemarie H., Duijn, Bert Van
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 01-08-1998; OXFORD UNIVERSITY PRESS
• Subjects: Agronomy. Soil science and plant productions; Aleurone cells; Aleurone layer; Apoptosis; Barley; Barley aleurone; Biological and medical sciences; Cell and Molecular Biology, Biochemistry and Molecular Physiology; Cell walls; DNA fragmentation; Economic plant physiology; Embryo development. Germination; Embryos; Fundamental and applied biological sciences. Psychology; Germination; Germination and dormancy; Grains; Growth and development; hydrolytic enzymes; Imbibition; Plant physiology and development; programmed cell death; Monocotyledones; Aleurone; Hordeum vulgare; Enzyme; Germination; Spatial variation; Time variation; Cereal crop; Cell wall; Fragmentation; Hydrolysis; Regulation(control); Gramineae; Glycosidases; DNA; Angiospermae; Tagging; Hydrolases; Spermatophyta; α-Amylase; O-Glycosidases; Apoptosis
• ISSN: 0022-0957; 1460-2431
• DOI: 10.1093/jxb/49.325.1293

During germination of barley grains, the appearance of DNA fragmentation started in aleurone cells near the embryo and extended to the distal end in a timedependent manner. DNA fragmentation was demonstrated to occur only after the expression of a-amylase mRNA in the aleurone layer. In addition, cell wall degradation started in cells near the embryo on the sides facing the endosperm. Subsequently cell wall degradation extended to the lateral cell walls and to cells more to the distal end of the grain. A typical alteration of the nucleus was observed by electron microscopy and an almost complete degradation of DNA was found in the nucleus while the nuclear envelope remained intact. The results indicate that programmed cell death occurred in aleurone cells during germination. A model is proposed for the regulation of programmed cell death in aleurone cells during germination involving ABA levels and cell wall degradation.