The dehydration tolerance of leaf membranes of three coconut palm (
Cocos nucifera L.) cultivars with different levels of resistance to drought stress in the field was evaluated by analysis of ...membrane lipids. Young plants, grown singly in pots, were subjected to controlled dehydration by witholding watering. The composition of coconut leaf lipids was similar to that of higher plants of the so-called ‘18:3 (α-linolenic)’ group, although the total lipid content was lower than that of herbaceous tropical crops. In response to drought stress, leaf total lipid and chloroplastic major lipid (monogalactosyl diacylglycerol) contents decreased more markedly in the more drought-susceptible cultivars. Analysis of leaf lipids is thus proposed as an early screening test for tolerance to drought stress. Despite the decrease in lipid contents, no modification of the fatty acid composition of total lipid extract and of monogalactosyl diacylglycerol was revealed, suggesting a high membrane tolerance to desiccation in
Cocos. The fatty acid composition of the major phospholipid (phosphatidylcholine) was markedly enriched in α-linolenic acid in response to water deficit, suggesting a slowing down of monogalactosyl diacylglycerol biosynthesis and/or an adaptation to drought stress.
Etude de differents parametres physiologiques (echanges gazeux foliaires, etat hydrique foliaire, teneur en lipides de la membrane foliaire) chez des cocotiers ages de 2 ans cultives en pots sous ...deficit hydrique controle, et appartenant a une variete naine (sensible a la secheresse), une var. grande (moderement sensible) et une hybride (resistante). Seule l' analyse des lipides membranaires des feuilles semble pouvoir etre utilisee pour la selection des varietes. L' acide linolenique du MGDG presente, sous stress hydrique severe, une chute de sa teneur de 58, 38 et 19 % respectivement chez les var. naine, grande et hybride.
Etude de differents parametres physiologiques (echanges gazeux foliaires, etat hydrique foliaire, teneur en lipides de la membrane foliaire) chez des cocotiers ages de 2 ans cultives en pots sous ...deficit hydrique controle, et appartenant a une variete naine (sensible a la secheresse), une var. grande (moderement sensible) et une hybride (resistante). Seule l' analyse des lipides membranaires des feuilles semble pouvoir etre utilisee pour la selection des varietes. L' acide linolenique du MGDG presente, sous stress hydrique severe, une chute de sa teneur de 58, 38 et 19 % respectivement chez les var. naine, grande et hybride.
Effect of water stress on esterase activity of cotton leaves Tashakorie, A. (Universite de Paris-7 (France). Laboratoire d'Ecologie Generale et Appliquee); Clerc, M; Anh Thu Pham Thi ...
Comptes rendus des séances de l'Académie des sciences. Série 3, Sciences de la vie,
(30 Dec 1985), Letnik:
301, Številka:
6
Journal Article
