Ectopic expression of NAC094 induces premature nodule senescence in Lotus japonicus.

To investigate the function of NAC094 in vivo, we overexpressed NAC094 in the infected cells of nodules using an L. japonicus Lb2 expression cassette. To this end, we used a GUS overexpression construct as control and analysed stably transformed plants to detect symbiotic phenotypes. Results show that overexpression of NAC094 causes premature senescence of nodules. To identify the mechanism by which NAC094 regulates nodule senescence, we performed a transcriptome profiling analysis of nodules at 3 wpi. Around 13,850 differentially expressed genes (DEGs) were identified by comparing NAC-OE with control nodules (Log2FC > 1, FDR < 0.05). Of these, 7,516 were up-regulated (NAC-OE-UP) and 6,334 were down-regulated (NAC-OE-DOWN). Overall design: we performed a transcriptome profiling analysis of nodules at 3 wpi by comparing NAC-OE with control (GUS-OE) nodules, each with three biological replicates.