Characterization of PyMAPK2, a D group mitogen-activated protein kinase gene from Pyropia yezoensis responding to various abiotic stress

Abstract Mitogen-activated protein kinase (MAPK) signaling cascades are ubiquitous in eukaryotes and play a pivotal role in a range of biotic and abiotic stress responses. Phosphorylated mitogen-activated protein kinase is the last component of the cascade pathway and activates cellular responses. Pyropia yezoensis (Rhodophyta), a red alga, grows in intertidal zones. Here, we systematically analyzed PyMAPK2 (Group D) expression patterns at the mRNA and protein levels in response to different abiotic stresses. The results showed that PyMAPK2 responded to various stresses with different patterns. Yeast two-hybrid assays indicated that 17 candidate proteins putatively interacted with PyMAPK2. Bimolecular fluorescence complementation analysis confirmed that two cytoskeleton-related proteins, PyActin3 and PyFasciclin, interacted with PyMAPK2 in onion epidermal cells. PyActin3 and PyFasiclin mRNA expression also increased significantly in response to desiccation/rehydration stress. This study helps to clarify the molecular mechanisms and signal pathways associated with PyMAPK2 that regulate the response of P. yeozensis to environmental stresses.