Genetic manipulations of TaARE1 boost nitrogen utilization and grain yield in wheat.

Nitrogen is a key element essential for plant growth and crop pro-duction,and the improvement of the nitrogen use efficiency (NUE) of crops largely contributes to yield production.The improvement of NUE is a major challenge in agriculture,not only for reducing the planting cost of crops,but also for that of environmental pollution caused by the excessive application of nitrogen fertilizers (Bobbink et al.,2010;Ladha et al.,2016).Nitrogen utilization in nonlegume plants involves complex processes,mainly including absorption,transport,assimilation,and reutilization.Ammonium and nitrate,the two most abundant inorganic nitrogen in soil,are the primary nitrogen sources available for plants (Xu et al.,2012).Ammonium directly absorbed by ammonium transporter or generated from nitrate reduc-tion is assimilated into amino acids via the glutamine synthase/gluta-mine:2-oxoglutarate aminotransferase (GS/GOGAT) cycle.In rice,weak mutant alleles of the ferredoxin-dependent GOGAT (Fd-GOGAT;also known as ABNORMAL CYTOKININ RESPONSE1 or ABC1) gene cause severe abnormalities associated with nitrogen deficiency,whereas null mutations are seedling lethal (Yang et al.,2016).Notably,the nitrogen-deficient phenotype of the abc1 weak allele is partially suppressed by an abc1 repressor1 (are1) mutation.