On the Physiological Role of Anaerobically Synthesized Lipids in Oryza sativa Seedlings

Generosova, I.P. and Vartapetian, B.B. (2005) On the Physiological Role of Anaerobically Synthesized Lipids in Oryza sativa Seedlings. Russian Journal of Plant Physiology, 52 (4). pp. 481-488.

[img] PDF - Published Version
Restricted to ICRISAT researchers only


The objective of this work was to elucidate a possible adaptive role of lipid biosynthesis and unsaturated fatty acids (FAs), esterified to lipids, as terminal acceptors of electrons, alternative to molecular oxygen, in the shoots of rice seedlings (Oryza sativa L.) under conditions of strict anoxia. Biosynthesis of lipids and their accumulation, as well as the reduction of double bonds in unsaturated FAs, were studied by electron microscopic observation of the accumulation of lipid bodies in the cytoplasm and by the biochemical analysis of FAs in shoot lipids before and after anaerobic incubation of the shoots. The experiments were carried out with intact coleoptiles after 5 and 8 days of anaerobic germination of seeds (primary anoxia) and with detached shoots, preliminarily grown in air and then subjected to anoxia in the presence of 2% glucose for 48 h (secondary anoxia). In these experiments, lipid bodies did not accumulate in the cytoplasm under anoxic conditions. Lipid bodies appeared only during 48-h anaerobic incubation of detached coleoptiles in the absence of exogenous glucose, when mitochondria degraded. There was no change either in the double bond index of FAs, or in the qualitative and quantitative composition of FAs during shoot anaerobic incubation. We conclude that neither lipids synthesized under anaerobic conditions nor esterified unsaturated FAs are involved in plant adaptation to anaerobiosis as terminal acceptors of electrons, alternative to molecular oxygen. Lipid biosynthesis under anoxic conditions, which was demonstrated for anoxia-tolerant seedlings of Oryza sativa and Echinochloa phyllopogon in experiments with radioactive precursors, 14C-acetate and 3H-glycerol, is only the manifestation of a turnover of saturated FAs and various classes of lipids, which stabilizes cell membranes under adverse conditions of strict anoxia.

Item Type: Article
Additional Information: This work was supported by the Russian Foundation for Basic Research, project no. 00-04-48234.
Uncontrolled Keywords: Oryza sativa, adaptation, anoxia, cell ultrastructure, coleoptiles and shoots, lipid metabolism
Author Affiliation: Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya ul. 35, Moscow, 127276, Russia
Subjects: Crop Improvement
Crop Improvement > Seed Technology
Plant Physiology and Biochemistry > Plant Physiology
Divisions: Other Crops
Depositing User: Mr Arbind Seth
Date Deposited: 21 Dec 2012 05:42
Last Modified: 21 Dec 2012 05:42
Official URL: http://dx.doi.org/10.1007/s11183-005-0071-0
URI: http://eprints.icrisat.ac.in/id/eprint/8988

Actions (login required)

View Item View Item