Fig. 1.

A model of phytocytokine maturation and release. After translation, phytocytokine precursors with signal peptide enter into the ER-Golgi secretory pathway, where they undergo post-translational modifications and proteolytic cleavages to remove signal peptide and prodomain, and then are secreted into the apoplast. Phytocytokine precursors without signal peptide enter into the cytosol, where they are maturely processed to remove prodomains. This group of phytocytokines are released into the apoplast likely through unconventional secretion or disrupted plasma membrane. The maturation processing of phytocytokine may also happen in the apoplast