Abstract
Glutamate is well established as an important signaling molecule in the mammalian central nervous system. However, it has long been believed that this signaling pathway does not function in plants, which have no nervous system. During the past decade, evidence has unexpectedly emerged that glutamate signaling occurs in higher plants. Completion of the Arabidopsis genome project revealed that the 20 AtGLR genes are homologous to mammalian ionotropic glutamate receptor genes. Glutamate receptors were found in roots; they mediated Ca influx through the cell membrane. Glutamate triggered an increase in cytoplasmic Ca concentration in Arabidopsis seedlings and affected root growth and branching.
At this meeting, we report the effect of glutamate on stomatal movement. Glutamate induced stomatal closure, which might occur as a result of increased cytoplasmic Ca concentration.
