01852naa a2200385 a 450000100080000000500110000800800410001910000240006024500870008426000090017150000420018052008550022265000150107765000150109265000120110765000130111965000180113265000110115065000130116165300130117465300200118765300110120765300110121865300130122965300110124265300100125365300220126370000200128570000180130570000190132370000210134270000260136370000170138977300600140611834912022-05-04       2000    bl uuuu     u00u1 u    #d1 aMAGALHAES, J. V. de  aInfluence of phosphorus stress on Ammonium uptake by maize.h[electronic resource]  c2000  aProdução científica/2000/CENARGEN.  aThe effect of phosphorus (P) starvation on ammonium (NH4) uptake was evaluated by growing single-cross seedlings of the make progenitor of the maize double-cross hybrid BR 201 in nutrient solution. The kinetics of NH4 uptake were measured after P starvation and non-starvation periodo of 2, 4, 6, 8 and 10 days. The effect of P addition during the study period (resupply) was also tested. Ammonium uptake decreased 45,7% after two days of P stress completed to the fully P-sufficient control. Ammonium uptake decreased 83,0% where P was withheld for 10 days. The decline in NH4 uptake was partially reversed when P was resupplied during the early periods of P deficiency, but this effect diminished as the P stress increased. These results suggest that maize plants are physiologically dependent on NH4, rather than nitrate (NO3) when under P stress.  aphosphorus  aAbsorção  aAmônia  aFósforo  aMilho Hibrido  aStress  aZea Mays  aAmmonium  aAmmonium uptake  aAmonio  aBR 201  aEstresse  aHybrid  aMaize  aPhosphorus stress1 aALVES, V. M. C.1 aNOVAIS, R. F.1 aMOSQUIM, P. R.1 aMAGALHAES, J. R.1 aBAHIA FILHO, A. F. C.1 aHUBER, D. M.  tJournal of Plant Nutritiongv.23, n.2, p.263-273, 2000.