Thermoperiod affects the diurnal cycle of nitrate reductase expression and activity in pineapple plants by modulating the endogenous levels of cytokinins - Freschi, Luciano; Nievola, Catarina Carvalho; Rodrigues, Maria Aurineide; Domingues, Douglas Silva; Van Sluys, Marie-Anne; Mercier, Helenice (Physiologia Plantarum, 2009)