Regulation of respiratory metabolism in germinating seeds.

Abstract : Germination and early seedling growth are critical periods in the life cycle of plants. Starting from a quiescent dry state in the seed, embryos and seedlings need to maintain an efficient heterotrophic metabolism and cope with often stressful conditions, in order to rapidly reach autotrophy and start competing for nutriments and space. These processes are almost entirely dependent on mitochondrial respiration, which provides cellular energy as well as a metabolic platform involved in the conversion of seed reserves into building blocks for growth metabolism. It is therefore no surprise that seed mitochondria exhibit unusual properties in respect of desiccation and temperature tolerance. Stress proteins such as LEA (late embryogenesis abundant) proteins and sHSPs (small heat shock proteins) are involved in the protection of mitochondria in the dry state, and likely contribute to their thermal tolerance during germination. In many cases, fast germination increases the chances of successful emergence and establishment of seedlings, and this requires an efficient energy metabolism. Oxygen availability for respiration can be a challenge because of limiting oxygen diffusion rates in large seeds and/or within soils. It appears that, at least in legume seeds, mitochondria are able to self-adjust their oxygen consumption with the support of nitric oxide (NO) metabolism. This allows maximal energy production to be achieved under hypoxic conditions, without subjecting tissues to deleterious anoxia. In the context of ongoing and future climate change, it is of general importance to understand how mitochondrial functions have evolved to maintain energy homeostasis in organisms and tissues exposed to extreme environmental conditions such as desiccation. Such traits could offer interesting targets for plant adaptation and improvement.
Type de document :
Communication dans un congrès
24th New Phytologist Symposium, Plant respiration and climate change: scaling from mitochondria to the globe, Jun 2010, Oxford (UK), United Kingdom
Liste complète des métadonnées

https://hal-agrocampus-ouest.archives-ouvertes.fr/hal-00729700
Contributeur : Céline Martel <>
Soumis le : vendredi 7 septembre 2012 - 15:52:01
Dernière modification le : vendredi 15 décembre 2017 - 15:46:03

Identifiants

  • HAL Id : hal-00729700, version 1

Collections

Citation

D. Macherel, A. Benamar, Marie-Hélène Avelange-Macherel. Regulation of respiratory metabolism in germinating seeds.. 24th New Phytologist Symposium, Plant respiration and climate change: scaling from mitochondria to the globe, Jun 2010, Oxford (UK), United Kingdom. 〈hal-00729700〉

Partager

Métriques

Consultations de la notice

164