%0 Journal Article
%9 ACL : Articles dans des revues avec comité de lecture non répertoriées par l'AERES
%A Campa, Claudine
%A Diouf, D.
%A Ndoye, I.
%A Dreyfus, Bernard
%T Differences in nitrogen metabolism of Faidherbia albida and other N2-fixing tropical woody acacias reflect habitat water availability
%D 2000
%L fdi:010025486
%G ENG
%J New Phytologist
%@ 0028-646X
%K LEGUMINEUSE TROPICALE ; FIXATION BIOLOGIQUE DE L'AZOTE ; MYCORHIZE ; METABOLISME ; ENZYME ; BESOIN EN EAU ; ETUDE COMPARATIVE
%K NITRATE REDUCTASE ; GLUTAMINE SYNTHETASE
%K ZONE ARIDE ; ZONE SEMIARIDE
%P 571-578
%R 10.1046/j.1469-8137.2000.00714.x
%U https://www.documentation.ird.fr/hor/fdi:010025486
%> https://horizon.documentation.ird.fr/exl-doc/pleins_textes/pleins_textes_7/b_fdi_57-58/010025486.pdf
%V 147
%W Horizon (IRD)
%X The activities of nitrate reductase and glutamine synthetase were evaluated in young plants of #Faidherbia albida$, a tropical woody legume, fed with different N sources under hydroponic conditions. Results showed that assimilation of both NO3- and NH4+ preferentially took place in shoots. A basal amount of nitrate reductase activity was detected in shoots of plants grown with an NO3- free solution or placed under N2-fixing conditions, and also in nodules of N2-fixing plants. This strongly suggests that constitutive nitrate reductase activity is present in these organs. Analyses of the soluble nitrogenous content showed that the major form of N in the different organs was alpha-amino acids (particularly amides), irrespective of the N status of the culture conditions. The same result was obtained for nodulated plants grown in local sandy soil. In this case, amide-N generally counted for more than 40% of the total soluble N. This was especially true in nodules. Ureide-N never exceeded 9% of the total soluble N and did not appear to increase with increasing nodule nitrogenase activity. Amides were also predominant in three N2-fixing Sahelian acacias (#Acacia seyal$, #A. nilotica$ and #A. tortilis$), showing that #F. albida$ does not differ from Sahelian #Acacia$ in terms of the metabolism of fixed N. However, like another Sahelian acacia growing preferentially near water (#A. nilotica$), #F. albida$ can be distinguished from acacias growing strictly in arid zones (#A. seyal$ and #A. tortilis$) in terms of initial growth, water and nitrate management. (Résumé d'auteur)
%$ 084SYMBIO02