Nitrate transport in plant through soil-root-shoot systems: a molecular view

Abstract

Nitrogen (N) is a macronutrient for plants. Nitrogen is a component of chlorophyll, amino acids, nucleic acids, and secondary metabolites. The aim of this molecular review is to provide an overall picture of the numerous membrane proteins that mediate transportation processes in different plant tissues. Nitrate transporters (NRT) from the NRT1 and NRT2 families ensure the capacity of root cells to absorb nitrate from soil, through high- and low-affinity systems (HATS and LATS) depending on different nitrate concentrations in the soil solution. Other NRT1 family members are involved subsequently in loading and unloading of nitrate to and from the xylem vessels, allowing its distribution to aerial organs or its mobilization from old leaves of plants and transport to other organs. Once it enters into the plant cell, nitrate can be stored in the vacuole by passing through the tonoplast, a step that involves chloride channels (CLC) or a member of NRT2 family. Finally, with the exception of one NRT1 member, nitrate transport toward the chloroplast is still unknown. All of these fluxes are controlled by the major tour operators like the internal nutritional status of plants but also by external abiotic factors such as water, light, radiation, temperature, humidity, soil etc.

Keywords:

• Nitrate
• NRT family
• CLC family
• transport
• genetic improvement

Disclosure statement

No potential conflict of interest was reported by the author.

Additional information

Funding

The authors are grateful for financial support from the Research and Training Center (RTC) (Grants code: 4829) at Patuakhali Science and Technology University (PSTU), Dumki, Patuakhali-8602, Bangladesh and also for Research Collaboration Fund provided by the University Grants Commission (UGC), Bangladesh.