Extracellular ATP Promotes Stomatal Opening of Arabidopsis thaliana through Heterotrimeric G Protein α Subunit and Reactive Oxygen Species

• Published in: Molecular plant Vol. 5; no. 4; pp. 852 - 864
• Main Authors: Hao, Li-Hua, Wang, Wei-Xia, Chen, Chen, Wang, Yu-Fang, Liu, Ting, Li, Xia, Shang, Zhong-Lin
• Format: Journal Article
• Language: English
• Published: England Elsevier Inc 01.07.2012
• Subjects: Adenosine Triphosphate - metabolism; Arabidopsis - anatomy & histology; Arabidopsis - cytology; Arabidopsis - metabolism; Arabidopsis thaliana; ATPase活性; Calcium - metabolism; Extracellular ATP; Extracellular Space - metabolism; GTP-Binding Protein alpha Subunits - chemistry; heterotrimeric G protein; NADPH氧化酶; Plant Stomata - anatomy & histology; Plant Stomata - cytology; Plant Stomata - metabolism; Protein Multimerization; Protein Structure, Quaternary; Protons; reactive oxygen species; Reactive Oxygen Species - metabolism; Signal Transduction; stomatal movement; 亚基; 异三聚体G蛋白; 拟南芥; 气孔开度; 活性氧物种; 胞外ATP; Arabidopsis thaliana; stomatal movement; Extracellular ATP; reactive oxygen species; heterotrimeric G protein
• ISSN: 1674-2052; 1752-9867
• DOI: 10.1093/mp/ssr095

In recent years, adenosine tri-phosphate （ATP） has been reported to exist in apoplasts of plant cells as a signal molecule. Extracellular ATP （eATP） plays important roles in plant growth, development, and stress tolerance. Here, extra- cellular ATP was found to promote stomatal opening of Arabidopsis thaliana in light and darkness. ADP, GTP, and weakly hydrolyzable ATP analogs （ATPγS, Bz-ATP, and 2meATP） showed similar effects, whereas AMP and adenosine did not affect stomatal movement. Apyrase inhibited stomatal opening. ATP-promoted stomatal opening was blocked by an NADPH oxidase inhibitor （diphenylene iodonium） or deoxidizer （dithiothreitol）, and was impaired in null mutant of NADPH ox- idase （atrbohD/F）. Added ATP triggered ROS generation in guard cells via NADPH oxidase. ATP also induced Ca^2＋ influx and H ＋ efflux in guard cells. In atrbohD/F, ATP-induced ion flux was strongly suppressed. In null mutants of the heterotrimeric G protein α subunit, ATP-promoted stomatal opening, cytoplasmic ROS generation, Ca^2＋ influx, and ^H＋ efflux were all sup- pressed. These results indicated that eATP-promoted stomatal opening possibly involves the heterotrimeric G protein, ROS, cytosolic Ca^2＋, and plasma membrane H＋-ATPase.