Research advances in nitrate uptake and transport in plants

【Objective】 Nitrate is one of the major nitrogen sources for higher plants, which most frequently limits the growth of plants. Recently, the mechanisms of nitrate uptake and transport to the aboveground parts in plants have received widespread attention. New phenomenons and conclusions have been revealed and thereby give us a new sight into the physiological and molecular mechanisms of nitrate uptake and transport in plants. In this review, the current worldwide research conducted on nitrate uptake and transport in plants was summarized in the physiological and molecular levels. Besides, the influence factors responsible for nitrate uptake in plants were also discussed by integrating the large amount of physiological data. Membrane bound transporters are required for nitrate uptake, allocation and storage inside the plants. Therefore, we also summarized the members and the functions of four gene families that encode the nitrate transporters, including nitrate transporter 1(NRT1), nitrate transporter 2(NRT2), chloride channel(CLC) and slow anion channel-associated(SLAC). We hope that the recent advances in molecular biology of nitrate uptake and transport can provide a more comprehensive theoretical basis for further research.