Mitogen-activated protein kinase; part of the MST11-MST7-PMK1 MAP kinase (MAPK) cascade that is essential for appressorium formation, penetration and invasive growth (PubMed:8946911, PubMed:11952120, PubMed:15749760, PubMed:21283781, PubMed:23085322, PubMed:23454094, PubMed:27059015). Central regulator of appressorium development that acts downstream of the cAMP signal (PubMed:8946911, PubMed:23591122). The MST11-MST7-PMK1 MAP kinase cascade transduces signals from the cell surface sensors MDB2 and SHO1 that recognize various surface signals such as surface hydrophobicity, cutin monomers, and rice leaf waxes (PubMed:21283781). Regulates expression of secreted fungal effector proteins implicated of host immune defenses, preventing reactive oxygen species generation and excessive callose deposition at plasmodesmata (PubMed:29567712). Furthermore, controls the hyphal constriction required for fungal growth from one rice cell to the neighboring cell, enabling host tissue colonization and blast disease (PubMed:29567712). Targets downstream of the PMK1-MAPK pathway include transcription factor MST12 and pathogenicity-related genes GAS1 and GAS2, both of which are expressed during appressorium formation, even if regulation of MST12 is not associated with expression of GAS1 or GAS2 (PubMed:12215509, PubMed:11952120, PubMed:23454094). ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-[protein] ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-threonyl-[protein] Phosphorylated by MST7. Impairs the formation of appressoria and the ability to infect rice plants, even when inoculated onto wounded leaves (PubMed:8946911, PubMed:23591122, PubMed:23454094). Leads to decreased transcription of the cell surface sensors MSB2 and SHO1 (PubMed:21283781). Blocks the transcription of both virulence genes GAS1 and GAS2 during appressorium formation (PubMed:12215509). Belongs to the protein kinase superfamily. CMGC Ser/Thr protein kinase family. MAP kinase subfamily.