Analysis of osmotic stress signaling in plants

Salinity, drought, and low temperature cause osmotic stress in plants and activate signalling pathways that regulate plant responses. The understanding of plant signalling pathways that respond to osmotic stress remains limited in spite of its importance for both basic biology and agriculture. Our previous study revealed that the SNF1-related protein kinase 2 family (SnRK2s) plays a central role in osmotic stress responses. In our project with model plant Arabidopsis thaliana, we will use genetics, and biochemical techniques to examine molecular interactions between SnRK2s and other signaling components in order to clarify the nature of osmotic stress pathways.   

Several literatures and our preliminary results suggest that osmotic stress induces posttranslational modification of SnRK2s. We will further characterize this modification to determine the activation mechanism of SnRK2s in the osmotic stress pathway. We will also determine the function of proteins that regulate SnRK2s in the osmotic stress pathway; these proteins have been identified in yeast two-hybrid screening. Because some key players in osmotic stress signaling have yet to be identified, other screenings will also be performed.

Through these projects, we expect to generate new knowledge regarding the regulatory mechanism of SnRK2s and proteins downstream of SnRK2s, which play central roles in osmotic stress signaling.