Maize phytocytokines modulate pro-survival host responses and pathogen resistance.
Abstract
Phytocytokines are signalling peptides that alarm plant cells of danger. However, the downstream responses triggered by phytocytokines and their effect on plant survival are still largely unknown. Here, we have identified three biologically active maize orthologues of phytocytokines previously described in other plants. The maize phytocytokines show common features with microbe-associated molecular patterns (MAMPs), including the induction of immune-related genes and activation of papain-like cysteine proteases. In contrast to MAMPs, phytocytokines do not promote cell death in the presence of wounding. In infection assays with two fungal pathogens we found that phytocytokines affect the development of disease symptoms, likely due to the activation of phytohormonal pathways. Collectively, our results show that phytocytokines and MAMPs trigger unique and antagonistic features of immunity. We propose a model in which phytocytokines activate immune responses partially similar to MAMPs but in contrast to microbial signals, they act as danger and survival molecules to the surrounding cells. Future studies will focus on the components determining the divergence of signalling outputs upon phytocytokine activation.
Read more at Mol Plant Microbe Interact