Transcriptional regulation of a rice mitogen-activated protein kinase gene, OsMAPK4, in response to environmental stresses.

Mitogen-activated protein kinase (MAPK) cascades play important roles in signal transduction of extracellular stimuli in eukaryotes. However, stimulatory signals for plant MAPKs have not been well elucidated. Here, a cDNA clone, termed Oryza sativa MAPK4 (OsMAPK4), from rice encoding a protein that showed homology with the eukaryotic MAPKs was isolated.

Expression of Oryza sativa MAP kinase gene is developmentally regulated and stress-responsive.

Mitogen-activated protein kinase (MAPK) pathways are modules involved in the transduction of extracellular signals to intracellular targets in all eukaryotes. In plants, there is evidence for MAPKs playing a role in the signalling of abiotic stresses, pathogens, plant hormones, and cell cycle cues. The large number and divergence of plant MAPKs indicates that this ancient mechanism of signal transduction is extensively used in plants.