Physiological, biochemical and molecular analysis of sugar‐starvation responses in tomato roots
Two‐month‐old tomato plants were submitted to day/night cycles and to prolonged darkness in order to investigate the physiological and biochemical response to sugar starvation in sink organs. Roots appeared particularly sensitive to the cessation of photosynthesis, as revealed by the reduction of th...
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Published in | Journal of experimental botany Vol. 54; no. 385; pp. 1143 - 1151 |
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Main Authors | , , , , , , |
Format | Journal Article |
Language | English |
Published |
Oxford
Oxford University Press
01.04.2003
OXFORD UNIVERSITY PRESS Oxford Publishing Limited (England) Oxford University Press (OUP) |
Subjects | |
Online Access | Get full text |
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Summary: | Two‐month‐old tomato plants were submitted to day/night cycles and to prolonged darkness in order to investigate the physiological and biochemical response to sugar starvation in sink organs. Roots appeared particularly sensitive to the cessation of photosynthesis, as revealed by the reduction of the growth rate and the decline of the carbohydrate and protein content. Therefore, excised tomato roots were used as a model to deepen the characterization of sugar starvation symptoms. In excised roots, the endogenous sugars were rapidly exhausted and significant degradation of protein was observed. Glutamine and asparagine accounted for most of the nitrogen released by protein breakdown. Respiration declined and proliferation‐ and growth‐associated genes were repressed soon after the beginning of the sugar depletion. Among the genes studied, only the gene encoding asparagine synthetase was strongly induced. All the starvation symptoms were reversible when the roots were resupplied with sugar. When the culture conditions deteriorated, the metabolic and molecular changes led to the triggering of apoptosis of the root cells. |
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Bibliography: | ark:/67375/HXZ-Z58MGZDK-K Received 2 August 2002; Accepted 25 November 2002 istex:913C2390670B6336CFE9C30327FB825C22AE5C0D 1 To whom correspondence should be addressed. Fax: +33 5 57 12 25 41. e‐mail: baldet@bordeaux.inra.fr Abbreviations: RT‐PCR, reverse transcriptase polymerase chain reaction; DW, dry weight. local:erg113 ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0022-0957 1460-2431 |
DOI: | 10.1093/jxb/erg113 |