Planta

, Volume 205, Issue 2, pp 153–164

Three-dimensional analysis of the senescence program in rice (Oryza sativa L.) coleoptiles

Investigations of tissues and cells by fluorescence microscopy
  • Noriko Inada
  • Atsushi Sakai
  • Haruko Kuroiwa
  • Tsuneyoshi Kuroiwa
Article

DOI: 10.1007/s004250050307

Cite this article as:
Inada, N., Sakai, A., Kuroiwa, H. et al. Planta (1998) 205: 153. doi:10.1007/s004250050307

Abstract.

The coleoptile of rice (Oryza sativa L. cv. Nippon-bare) emerges from an imbibed seed on day 2 after sowing. Then, it matures and senesces rapidly. For analysis of the senescence pattern within individual coleoptiles, we monitored the distribution of chlorophyll (Chl) in entire coleoptiles and in cross-sections of coleoptiles by recording the autofluorescence of Chl. Degradation of Chl was apparent at the tip of the margins of opened-out coleoptiles on day 4, when the overall levels of soluble protein and Chl per coleoptile had reached maximum values. Then, senescence proceeded from the tip to the base and from the inner mesophyll cells towards the outer epidermis, excluding tissues along vascular bundles. Further analysis of cellular senescence using samples embedded in Technovit 7100 resin revealed that the senescence of each green mesophyll cell followed an identical program, which consisted of the following steps: (i) degradation of chloroplast DNA; (ii) condensation of the nucleus, decrease in the size of chloroplasts, degradation of ribulose-1,5-bisphosphate carboxylase/oxygenase and chloroplast inner membranes; (iii) disorganization of the nucleus; (iv) complete loss of cellular components, distortion of the cell wall. Although the timing of each step and the rate at which each step was completed differed among cells of different locations within the coleoptile, this sequence was observed in all mesophyll cells in the coleoptile.

Key words: Cell wall Chloroplast Chloroplast DNA Coleoptile Oryza (senescence) Senescence 

Copyright information

© Springer-Verlag Berlin Heidelberg 1998

Authors and Affiliations

  • Noriko Inada
    • 1
  • Atsushi Sakai
    • 1
  • Haruko Kuroiwa
    • 2
  • Tsuneyoshi Kuroiwa
    • 1
  1. 1.Department of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo, Tokyo 113, JapanJP
  2. 2.Division of Biology, Kyoritsu Women's Junior College, Kanda, Tokyo 102, JapanJP

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