The immediate cause of the diurnal changes of nitrogen metabolism in leaves of nitrate replete tobacco: a major imbalance between the rate of nitrate reduction and the rates of nitrate uptake and ammonium metabolism during the first part of the light period. - Matt,P..; Geiger,M..; Walch-Liu,P..; Engels,C..; Krapp,A..; Stitt,M.. (Plant, Cell and Environment, 2001)