02055naa a2200313 a 450000100080000000500110000800800410001902000180006010000210007824501130009926000090021230000140022150002560023552009810049165000100147265000170148265000150149965000110151465000130152565300150153865300240155365300110157765300210158865300250160965300110163470000150164570000150166077300660167516458462000-05-18       2000    bl uuuu     u00u1 u    #d  a85-87697-05-61 aCALATAYUD, P.-A.  aEstimation of carbon and nitrogen modification in leaves of Manihot esculenta Crantz during water deficiency  c2000  ap.288-298  aIn:INTERNATIONAL SCIENTIFIC MEETING ON CASSAVA BIOTECHNOLOGY, 1998. Salvador-Bahia. Proceedings... Brasilia, DF: Embrapa Recursos Geneticos e Biotecnologia/CBN, 2000. 625p. Editado por Luiz J. C. B. Carvalho, Ann Marie Thro, Alberto Duarte Vilarinhos.  aSeveral pests (mealybugs, whiteflies and mites) affect cassava yield, causing severe crop damage and long dry periods that frequently inducea strong outbreak in the pest population. This phenomenon partly depends on the changes in the trophic quality of the plant. Thus, the present research is focused on changes that water limitation may trigger in the biochemistry of cassava leaves (carbon and nitrogen metabolism). After limited water supply for 45 days in glasshouse conditions, cassava leaves exhibited an increase in g13C and pgosphoenolpyruvate carboxylase activity. This was associated with a very low leaf conductance. Enhanced phosphoglycolate phosphatase activity indicates that photorespiration may have increased. The free amino acids level was higher in water starved plants. The amino acid composition was also affected showing mainly a decrease in the proportion of aspartic acid, glutamic acid and alanine and an increase in that of asparagine and arginine.  apests  awater stress  aCochonilha  aEnzima  aMandioca  aAdealy-bug  aBiochemical changes  aEnzime  aEstresse hidrico  aMudancas bioquimicas  aPragas1 aDUCHON, S.1 aLAMAZE, T.  tBrasilia: Embrapa Recursos Genetico e Biotecnologia/CBN, 2000