摘要Nitrogen (N) availability is a major limiting factor for plant growth and agricultural productivity. Al-though the gene regulation network in response to N starvation has been extensively studied, it re-mains unknown whether N starvation has an im-pact on the activity of transposable elements (TEs). Here, we report that TEs can be transcrip-tionally activated in Arabidopsis under N starva-tion conditions. Through genetic screening of idm1-14 suppressors, we cloned GLU1, which encodes a glutamate synthase that catalyzes the synthesis of glutamate in the primary N assim-ilation pathway. We found that glutamate syn-thase 1 (GLU1) and its functional homologs GLU2 and glutamate transport 1 (GLT1) are redundantly required for TE silencing, suggesting that N me-tabolism can regulate TE activity. Transcriptome and methylome analyses revealed that N starva-tion results in genome-wide TE activation without inducing obvious alteration of DNA methylation. Genetic analysis indicated that N starvation-induced TE activation is also independent of other well-established epigenetic mechanisms, in-cluding histone methylation and heterochromatin decondensation. Our results provide new insights into the regulation of TE activity under stressful environments in planta.