caa a22 4500 477101852 CHVBK 20180405111544.0 cr unu---uuuuu 170330e19960801xx s 000 0 eng 10.1007/BF00195191 doi (NATIONALLICENCE)springer-10.1007/BF00195191 Effect of drought stress on net CO2 uptake by Zea leaves [Elektronische Daten] [Karen Saccardy, Gabriel Cornic, Jeanne Brulfert, Agnes Reyss] The net CO2 assimilation by leaves of maize (Zea mays L. cv. Adonis) plants subjected to slow or rapid dehydration decreased without changes in the total extractable activities of phosphoenolpyruvate carboxylase (PEPC), malate dehydrogenase (MDH) and malic enzyme (ME). The phosphorylation state of PEPC extracted from leaves after 2-3 h of exposure to light was not affected by water deficit, either. Moreover, when plants which had been slowly dehydrated to a leaf relative water content of about 60% were rehydrated, the net CO2 assimilation by leaves increased very rapidly without any changes in the activities of MDH, ME and PEPC or phosphorylation state of PEPC. The net CO2-dependent O2 evolution of a non-wilted leaf measured with an oxygen electrode decreased as CO2 concentration increased and was totally inhibited when the CO2 concentration was about 10%. Nevertheless, high CO2 concentrations (5-10%) counteracted most of the inhibitory effect of water deficit that developed during a slow dehydration but only counteracted a little of the inhibitory effect that developed during a rapid dehydration. In contrast to what could be observed during a rapidly developing water deficit, inhibition of leaf photosynthesis by cis-abscisic acid could be alleviated by high CO2 concentrations. These results indicate that the inhibition of leaf net CO2 uptake brought about by water deficit is mainly due to stomatal closure when a maize plant is dehydrated slowly while it is mainly due to inhibition of non-stomatal processes when a plant is rapidly dehydrated. The photosynthetic apparatus of maize leaves appears to be as resistant to drought as that of C3 plants. The non-stomatal inhibition observed in rapidly dehydrated leaves might be the result of either a down-regulation of the photosynthetic enzymes by changes in metabolite pool sizes or restricted plasmodesmatal transport between mesophyll and bundle-sheath cells. Springer-Verlag, 1996 Carbon dioxide (high concentrations) nationallicence Drought stress nationallicence Phospho enol pyruvate carboxylase nationallicence Photosynthesis nationallicence Stomatal/non-stomatal effects nationallicence Zea nationallicence A : net CO2 uptake by leaves nationallicence gc : leaf conductance for CO2 nationallicence ME : malic enzyme nationallicence MDH : malate dehydrogenase nationallicence PEPC : phosphoenolpyruvate (carboxylase) nationallicence PPFD : photosynthetically-active photon flux density nationallicence Rubisco : ribulose 1,5-bisphosphate carboxylase/oxygenase nationallicence RWC : relative water content nationallicence Saccardy Karen Laboratoire d'Ecologie Végétale, Groupe Photosynthèse et Environnement, Université de Paris XI, Bât. 362, F-91405, Orsay Cedex, France aut Cornic Gabriel Laboratoire d'Ecologie Végétale, Groupe Photosynthèse et Environnement, Université de Paris XI, Bât. 362, F-91405, Orsay Cedex, France aut Brulfert Jeanne Institut de Biotechnologie des Plantes, Université de Paris XI, Bât. 650, F-91405, Orsay Cedex, France aut Reyss Agnes Institut de Biotechnologie des Plantes, Université de Paris XI, Bât. 650, F-91405, Orsay Cedex, France aut Planta Springer-Verlag 199/4(1996-08-01), 589-595 0032-0935 199:4<589 1996 199 425 https://doi.org/10.1007/BF00195191 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00195191 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Saccardy Karen Laboratoire d'Ecologie Végétale, Groupe Photosynthèse et Environnement, Université de Paris XI, Bât. 362, F-91405, Orsay Cedex, France aut NATIONALLICENCE 700 1- Cornic Gabriel Laboratoire d'Ecologie Végétale, Groupe Photosynthèse et Environnement, Université de Paris XI, Bât. 362, F-91405, Orsay Cedex, France aut NATIONALLICENCE 700 1- Brulfert Jeanne Institut de Biotechnologie des Plantes, Université de Paris XI, Bât. 650, F-91405, Orsay Cedex, France aut NATIONALLICENCE 700 1- Reyss Agnes Institut de Biotechnologie des Plantes, Université de Paris XI, Bât. 650, F-91405, Orsay Cedex, France aut NATIONALLICENCE 773 0- Planta Springer-Verlag 199/4(1996-08-01), 589-595 0032-0935 199:4<589 1996 199 425 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer