Biography
Biography: Yong Wang
Abstract
We identified a novel gene named NITRATE REGULATORY GENE 2 (NRG2) by using forward genetics, which mediates nitrate signaling in Arabidopsis. nrg2 mutants showed inhibited induction of nitrate-responsive genes after nitrate treatment by an ammonium-independent mechanism. The nitrate content in roots was significantly lower in the mutants than in WT, which may have resulted from reduced expression of NRT1.1 and up-regulation of NRT1.8. Genetic and molecular data suggest that NRG2 functions upstream of NRT1.1 in nitrate signaling. Furthermore, NRG2 directly interacts with NLP7 in the nucleus, but does not affect the nuclear retention of NLP7 in the presence of nitrate. Transcriptomic analysis revealed that genes involved in four nitrogen-related clusters were differentially expressed in the nrg2 mutants. A nitrogen -compound-transport cluster was regulated by both NRG2 and NRT1.1, while no nitrogen-related clusters showed regulation by both NRG2 and NLP7. Thus, NRG2 plays a key role in nitrate regulation in part through modulating NRT1.1 expression and may function with NLP7 via their physical interaction. NRG2 family consists of 16 members and each protein contains two uncharacterized functional domains: DUF630 and DUF632. We further investigated the role of NRG2.10 and NRG2.15 in regulating nitrate signaling in Arabidopsis. The results showed that the induction of nitrate-responsive genes after nitrate treatments and the nitrate accumulation in seedlings were affected in both nrg2.10 and nrg2.15 mutants. These findings demonstrate that NRG2 family members play important roles in nitrate signaling.