The Arabidopsis nucleoporins 98A/B are essential for NLP7 nuclear accumulation in response to nitrate

The nuclear compartment is an essential evolutionary gain in eukaryotes. Stimulus-induced nuclear accumulation of transcription factors allows rapid and reversible regulation of gene expression. Nitrate-regulated nuclear accumulation of the master transcriptional regulator NLP7, a member of the RWP-RK family of transcription factors, triggers a major gene expression cascade. Whether and how this process is regulated at the level of the nuclear pore remains elusive. Here we show that the mobile nucleoporin NUP98A and its close homolog NUP98B interact with NLP7 in the nucleus and that the nitrate-triggered nuclear accumulation of NLP7 is impaired in their absence. We also showed that the simultaneous loss of NLP7 and NUP98A strongly and specifically alters the expression of nitrate-regulated genes and drastically reduces plant growth. Our results indicate that plant NUP98 acts on nitrate use by plants through its interaction with the top-tier NLP7 transcription factor.