玉米对氮素形态的反应及机制研究进展OA北大核心CSTPCD

[Objectives]Nitrate(NO3--N)and ammonium(NH4+-N)are the two main forms of inorganic nitrogen(N)absorbed by plants from soil.Maize(Zea mays L.)is a typical dry-land crop,some studies proved that NO3--N was the major form for maize absorption,however,there were a fewer of studies showing that supplying NH4+-N was more beneficial for the growth of maize than supplying NO3--N.In this paper,we summarized the N source preference of maize in different environments,and the gene families related to the absorption and transportation of NO3--N or NH4+-N in maize,aiming to clarify the response of physiological processes such as root development,carbon and nitrogen metabolism,photosynthesis,mineral element absorption,and stress resistance to the two N forms,in order to provide a basis for efficient N utilization and optimized N fertilizer management in maize.[Major advances]The N source preference of maize varied depending on the external environmental factors,among which the medium pH was considered as one of important factors.Maize grown in acidic soils preferred NO3--N,while in alkaline soils it preferred NH4+-N.Compared to the single N form,appropriate NO3--N/NH4+-N ratios were more conducive to N absorption and yield improvement in maize.In the maize genome,4 NRT2 is responsible for encoding high affinity nitrate transport system,79 NPF for low affinity nitrate transport system,8 AMT for high affinity ammonium transport system,and 2 AMF1 for low affinity ammonium transport system.Nitrate and NH4+-N not only serve as important nutrient resources,but also as signaling factors that participate in and regulate maize root development,carbon and nitrogen metabolism,photosynthesis,mineral element absorption,and stress resistance.[Expectations]In order to improve the N-fertilizer utilization efficiency of maize and clarify the mechanism of N forms affecting maize growth,development,and physiological processes,further researches should focus on the molecular mechanisms of absorbing and transporting NO3--N and NH4+-N by maize,the mechanism of promoting maize growth by the mixed application of NH4+-N and NO3--N,and field validation experiments on the impact of N form on maize growth and yield.