LeNRT1.1 Improves Nitrate Uptake in Grafted Tomato Plants under High Nitrogen Demand.

摘要: Grafting has become a common practice among tomato growers to obtain vigorous plants. These plants present substantial increase in nitrogen (N) uptake from the root zone. However, mechanisms involved this higher capacity have not been investigated. To elucidate whether N grafted under high demand conditions is related functioning of low- (high capacity) or high-affinity (low plasma membrane transporters, series experiments were conducted. Plants onto rootstock, as well ungrafted and homograft plants, exposed two radiation levels (400 800 µmol m−2 s−1). We assessed nitrate transporters (LeNRT1.1, LeNRT1.2, LeNRT2.1, LeNRT2.2 LeNRT2.3) expression, Michaelis‒Menten kinetics parameters (Vmax Km), leaf reductase activity, respiration rates. The majority mediated by LeNRT1.1 LeNRT1.2 Under conditions, rootstocks show similar expression for whereas LeNRT1.2. No differences (evaluated Vmax), rates, assimilation found treatments.