The Role of Gibberellins in Regulation of Nitrogen Uptake and Physiological Traits in Maize Responding to Nitrogen Availability.

Modified gibberellin (GA) signaling leads to semi-dwarfism with low nitrogen (N) use efficiency (NUE) in crops. An understanding of GA-mediated N uptake is essential for the development of crops with improved NUE. The function of GA in modulating N uptake capacity and nitrate (NO) transporters (NRTs) was analyzed in the GA synthesis-deficient mutant z grown under low (LN) and sufficient (SN) N conditions. LN significantly suppressed the production of GA, GA and GA, and the plants showed more sensitivity in shoots as well as LN stress. Moreover, the higher anthocyanin accumulation and the decrease of chlorophyll content were also recorded. The net NO fluxes and N content were decreased in plants under both LN and SN conditions. Exogenous GA could restore the NO uptake in plants, but uniconazole repressed NO uptake. Moreover, the transcript levels of were downregulated in plants, while the GA application enhanced the expression level. Furthermore, the RNA-seq analyses identified several transcription factors that are involved in the GA-mediated transcriptional operation of related genes. These findings revealed that GAs influenced N uptake involved in the transcriptional regulation of and physiological responses in maize responding to nitrogen supply.