Abstract:
Nitrogen (N) is a primary mineral nutrient for plant growth and development as well as the limiting factor for crop yield. Nitrate is one of the major N sources for plant uptake and utilization. Four gene families including
NPF,
NRT2,
CLC and
SLAC1/
SLAH have been reported to be involved in the process of nitrate uptake and utilization. Among the four gene families, the
NPF family has a large number of members and diverse functions, which have attracted more attention and in-depth research in recent years. There are 53, 93, 79 and as many as 331
NPF genes in the model plant
Arabidopsis and the main food crops – rice, maize, and wheat, respectively. The biological functions of more than half members (31/53) of
Arabidopsis NPF family have been characterized, and reports on the functions of
NPF genes in crop such as rice are emerging. Research revealed that
NPF genes are widely involved in processes of plant nitrogen uptake and its regulation, transport, distribution and re-distribution, and some members play important roles in the modification and improvement of crop nitrogen use efficiency (NUE). Consequently, it is highly pertinent to unravel the mechanism underlying plant nitrogen utilization and genetic improvement by exploring candidate
NPF genes from the perspective of nitrogen flow. This paper reviewed the biological functions of
NPF genes in the model plant
Arabidopsis and crops. At the moment, only 4 members of
NPF genes in maize were reported with biological functions, and none of the
NPF genes in wheat were reported with biological function. The exploration and studies on the
NPF genes of crops such as maize and wheat will provide gene resources for future researches on crop NUE improvement and high-NUE crop breeding.