Influence de la sécheresse sur l'ultrastructure mitochondriale chez le cotonnier — Quelques implications métaboliques

Abstract

Ultrastructural studies of Cotton leaves show that under water stress, mitochondria are, along with chloroplasts, the most susceptible cell organelles. The damage are, in time order: Swelling of cristae, loss of polyribosomes, local breakdown of the external membrane. Under severe water stress, mitochondria appear like empty bags. The development is much more slow in Gossypium anomalum , a drought-resistant species, than in G. hirsutum , a sensitive one. These ultrastructural modifications are discussed in connection with nitrogen metabolism and photorespiratory metabolism. The role of membrane stability in water stress tolerance is also assessed.