Table 1.

Overlaps between nodule transcriptome responses to systemic N signaling and PEG signaling.

Term	Transcript numbers	Proportion in PEG_DATs %	Enrichment FDR
SN2 in PEG	3,838	56	7.63.10-90
DN2 in PEG	1,465	66	8.22.10-86
(DN2 or/and SN2) in PEG	4,277	57	1.04.10-110

The total number of significantly expressed nodule transcript detected in this study was 23,610. Among them, differentially accumulated transcripts in response to PEG were 10,904 (PEG_DATs). The DN₂ and SN₂ mature nodule transcripts, responding respectively to systemic signaling of N Deficit and N Satiety, identified by Lambert et al. (2020b) were assigned to the MtruncA17r5.0 annotation by blast (1,465 and 3,838 transcripts, respectively). Specific enrichments of these DN₂ and/or SN₂ transcripts in the PEG_DATs list were evaluated using hypergeometric tests relative to all accumulated transcripts of the organ as a reference. Enrichment was declared when the false discovery rate (FDR) associated with the hypergeometric test was lower than 0.05.