Fig. 7.

Model for signalling of egg-induced gene expression in Arabidopsis. Upon egg oviposition, as yet unknown egg-associated molecular patterns (EAMP) are recognized by plant surface receptors and activate EDS1-dependent SA accumulation. SA promotes the conversion of EAMP-induced superoxide (O₂ ^–) to hydrogen peroxide (H₂O₂), which in turn leads to the translocation of NPR1 to the nucleus. Association of NPR1 with as yet unknown transcription factors (TFs) controls the up-regulation of PR-1 and other SA-dependent genes. Eggs also activate an NPR1-independent induction of SA-responsive genes. In the model, NUDT7 acts as a negative regulator of EDS1 activity.