Localization of muscarinic acetylcholine receptor in plant guard cells

Acetylcholine (ACh), as an important neurotransmitter in animals, also play s a significant role in various kinds of physiological functions in plants. But relatively little is known about its receptors in plants. A green fluo rescence BODIPY FL-labeled ABT, which is a high affinity ligand of muscarin ic acetylcholine receptor (mAChR), was used to localize mAChR in plant guar d cells. In Vicia faba L, and Pisum sativum L., mAChR was found both on the plasma membrane of guard cells, mAChR may also be distributed on guard cel l chloroplast membrane of Vicia faba L. The evidence that mAChR localizes i n the guard cells provides a new possible signal transduction pathway in AC h mediated stomata movement.