抄録
Reactive oxygen species (ROS) are short-lived molecules produced through various cellular mechanisms. In stomatal guard cells, ROS function as second messengers to mediate abscisic acid (ABA) signaling. The phytohormone ABA plays an essential role in protection of plants from environmental stresses. Previously, we showed that two NADPH oxidases AtrbohD and AtrbohF are responsible for ABA-triggered ROS production in guard cells, ABA-activation of plasma membrane calcium channels, and ABA-induced stomatal closure in Arabidopsis. Our recent study unequivocally shows that two Arabidopsis MAPK genes, MPK9 and MPK12, act downstream of ROS in guard cell ABA signaling. MPK9 and MPK12 are highly and preferentially expressed in guard cells, positively regulate ABA- and calcium-activation of anion channels and ABA-induced stomatal closure. Further progress will be discussed.
