| Abstract Detail
Intracellular Signaling Markus, Steven M [1], Tucker, Edward B [2]. Cytokinin Induced Bud Formation in Physcomitrella requires Phospholipase C Activity. The cytokinin family of phytohormones, initially identified for their ability to stimulate cell division, play an important role in plant morphogenesis via modulation of gene expression and enzymatic activity. In the moss Physcomitrella patens, cytokinins play a role in stimulating the development of buds which ultimately form the leafy gametophores. Accordingly, the addition of exogenous cytokinins to P. patens protonema results in the ectopic production of buds. The immediate events following cytokinin stimulation, while not fully understood, have been shown to require an increase in cytoplasmic calcium levels. However, the molecular triggers responsible for shaping the specific cytokinin-induced calcium signature are not known. Lipid-based signaling molecules are known to be important modulators of calcium signaling, including inositol-1,4,5-triphosphate (IP3), diacylglycerol (DAG) and phosphatidic acid. However, their role in mediating the cytokinin response is not known. To determine the role of these molecules in affecting the cytokinin response, we used an inhibitor of the enzyme responsible for producing two of these molecules – IP3 and DAG – in a bud formation assay. U-73122 has been shown to inhibit various isoforms of phospholipase C (PLC), including those found in plant cells. When added to P. patens protonema, we found that U-73122 inhibits the cytokinin-induced production of buds in a concentration-dependent manner. This supports the notion that cytokinin signals through the stimulation of PLC activity, and presumably through the production of the lipid-based signaling molecules IP3 and/or DAG. We are currently establishing the conditions necessary to determine the effects of this inhibitor on cytokinin-induced cytoplasmic calcium mobilization.
Log in to add this item to your schedule
1 - Baruch College, CUNY, Natural Sciences, 17 Lexington Avenue, Box A-0506, New York, NY, 10010, USA
2 - Baruch College, CUNY, Natural Sciences
Keywords:
Cytokinin
physcomitrella
Calcium
phospholipase
IP3.
Presentation Type: Plant Biology Abstract
Session: P
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM
Number: P33022
Abstract ID:1968 |
