| Abstract Detail
Salinity Kim, Beom-Gi [1], Waadt, Rainer [2], Cheong, Yong Hwa [3], Pandey, Girdhar K. [4], Dominguez-Solis, Jose R. [4], Schültke, Stefanie [5], Lee, Sung Chul [4], Kudla, Jörg [6], Luan, Sheng [4]. The Calcium Sensor CBL10 Mediates Salt Tolerance by Regulating Ion Homeostasis in Arabidopsis. Calcium serves as a critical messenger in many adaptation and developmental processes. Cellular calcium signals are detected and transmitted by sensor molecules such as calcium-binding proteins. In plants, the calcineurin B-like protein (CBL) family represents a unique group of calcium sensors and plays a key role in decoding calcium transients by specifically interacting with and regulating a family of protein kinases (CIPKs). We report here, that the calcineurin B-like protein CBL10 functions as a crucial regulator of salt tolerance in Arabidopsis. Cbl10 mutant plants exhibited significant growth defects and showed hypersensitive cell death in leaf tissues under high salt conditions. Interestingly, the Na+ contents of the cbl10 mutant, unlike other salt-sensitive mutants identified thus far, was significantly lower than in the wild type under either normal or high salt conditions, suggesting that CBL10 mediates a novel Ca2+-signaling pathway for salt “storage” mechanism. Indeed, the CBL10 protein physically interacts with the known salt-tolerance factor CIPK24/SOS2 and the CBL10- CIPK24/SOS2 complex is associated with the vacuolar compartments that are responsible for salt storage and detoxification in plant cells. These findings imply that CBL10 and CIPK24/SOS2 constitute a novel salt tolerance pathway that regulates the “sequestration/compartmentalization” of Na+ in plant cells. Because CIPK24/SOS2 also interacts with CBL4/SOS3 and regulates salt export across plasma membrane, our study identifies CIPK24/SOS2 as a multi-functional protein kinase that regulates different aspects of salt tolerance by interacting with distinct CBL calcium sensors. Log in to add this item to your schedule
1 - National Institute of Agricultural Biotechnology, Department of Plant physiology and biochemistry, 225 Seodun-dong Kwonsun-Ku, Suwon, 441-707, Korea 2 - Institut für Botanik und Botanischer Garten, Universität Münster 3 - Sunchon National University, Department of Bio-Environmental Science 4 - University of California, Berkeley, Department of Plant and Microbial Biology 5 - cInstitut für Botanik und Botanischer Garten, Universität Münster 6 - Institut für Botanik und Botanischer Garten, Universität Münster
Keywords: salt stress calcium signaling Arabidopsis Sodium sequestration.
Presentation Type: Plant Biology Abstract Session: P Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton Date: Sunday, July 8th, 2007 Time: 8:00 AM Number: P07017 Abstract ID:2665 |