Abstract
Methyl jasmonate (MeJA) induces stomatal closure similar to abscisic acid (ABA), but MeJA signaling in guard cells remains unclear. Here, we attempted the clarification of MeJA signaling in Arabidopsis guard cells using the MeJA-insensitive coi1 mutant. In the coi1 mutant, ABA induced stomatal closure but MeJA did not. MeJA induced production of reactive oxygen species (ROS) and nitric oxide (NO) in wild type guard cells. Furthermore we found that MeJA activated both S-type anion currents and ICa currents in wild type guard cell protoplasts. Production of ROS and NO and ion channel activation induced by MeJA were abolished in the coi1 mutant. In the ABA-insensitive abi2-1 mutant, similar to ABA, MeJA failed to induce stomatal closure but stimulated production of ROS and NO. Our results shed light in signaling transduction of MeJA-induced stomatal closure and show one model of signaling interaction between ABA and MeJA in Arabidopsis guard cells.
