Potassium, one of the three paramount plant macronutrients, is required for plant growth and thus it is a major constituent of fertilizers. Because of this potassium transport has been a vigorous and fruitful research topic, mostly in the most extensively studied model plant, Arabidopsis thaliana. Low-potassium (K+) adaptive responses in Arabidopsis have been strongly implicated in calcium signaling pathways and recent evidence suggests that this mode of calcium-mediated regulation of potassium transport (CARP) is evolutionarily conserved among plants. This then presents one of the primary challenges facing modern plant biology, namely the efficient translation of research findings in Arabidopsis to agriculturally important plants, like rice.
In this project, we will use computational biology to leverage the evolutionary conservation of CARP in plants to dissect the underlying molecular mechanisms involved in these responses. Our prediction, based largely on previous work in Arabidopsis, is that a specific rice calcium sensor, Calcineurin B-Like 1 (CBL1), works together with a protein partner, CBL-Interacting Protein Kinase 23 (CIPK23), in the phosphoregulation of potassium channels with homology to the Arabidopsis K+-Transporter 1 (AKT1). Using computational approaches, we have identified amino acid residues that are conserved across AKT1 homologs from distantly related plants. To identify regulatory sites required for channel activation, using site-directed mutagenesis to modify these conserved residues to identify the sites required for channel activation, which is studied using the two-electrode voltage clamp technique in oocytes. To verify function of potential regulatory sites in planta, we are generating transgenic plants containing AKT1 alleles with mutations in selected candidate sites. The anticipated findings will not only extend information gleaned from Arabidopsis research into rice but it will also advance our mechanistic understanding of a physiologically important plant response.
The selected student will assist with the identification of homozygous transgenic plants. Subsequently, the student will analyze the phenotypes in WT and transgenic plants under growth conditions with different potassium concentrations. The student will participate in lab meetings, make presentations, and potentially publish his or her research findings in a peer-reviewed journal.
Reliability, attention to detail, and passion for research are critical. Some laboratory experience outside of the classroom is preferable.