Nitrate regulation of nitrate uptake and nitrate reductase expression in barley grown at different nitrate:ammonium ratios at constant relative nitrogen addition rate

absorption de substances nutritives azote biomasa biomass biomasse crecimiento croissance disponibilidad de nutrientes growth growth rate hordeum vulgare nitrate nitrate reductase nitrates nitrato reductasa nitratos nitrogen nitrogen content nitrogen metabolism nutrient availability nutrient uptake racine roots stems tallo taux de croissance teneur en azote tige