PlMAPK10, a Mitogen-Activated Protein Kinase (MAPK) in , Is Required for Mycelial Growth, Sporulation, Laccase Activity, and Plant Infection.

Mitogen-activated protein kinase (MAPK) pathways are ubiquitous and evolutionarily conserved signal transduction modules directing cellular respond to a diverse array of stimuli, in the eukaryotic organisms. In this study, was identified to encode a MAPK in , the oomycete pathogen causing litchi downy blight disease. PlMAPK10, containing a specific and highly conserved dual phosphorylation lip sequence SEY (Serine-Glutamic-Tyrosine), represents a novel group of MAPKs as previously reported. Transcriptional profiling showed that expression was up-regulated in zoospore and cyst stages. To elucidate its function, the gene was silenced by stable transformation. silence did not impair oospore production, sporangium germination, zoospore encyst, or cyst germination but hindered hyphal growth, sporulation, pathogenicity, likely due to altering laccase activity. Over all, our results indicated that a MAPK encoded by gene in is important for pathogenic development.