- Polypyrimidine tract binding proteins

- The BEL1-like genes of potato

- Proteomic analyses

- Tethered function assay


Outreach and Internships






David Hannapel, Iowa State University

Jeff Coller, Case Western Reserve

Guru Rao, Iowa State University

Potato Phloem Biology Project

NSF Plant Genome Research Program


The overall scientific objective of this project is to uncover the network of signals that are responsible for the photoperiod-activated induction of tuber formation. Recent discoveries have demonstrated the role of a mobile RNA in a signaling system that activates tuber formation in potato. Potato is the 3rd most important food crop in the world and is an excellent nutritional source for both protein and carbohydrates. When considering calories generated for human consumption per acre, potato is the most productive food crop on the planet.We will address two hypotheses in this study: 1) Numerous RNAs of potato are transported via the phloem in a regulated fashion in response to internal and external cues; and 2) Proteins are present in the phloem that facilitate photoperiod-mediated transport, regulate repression of translation, affect RNA stability and degradation, and direct the movement of the RNA to its final destination. Several approaches will be undertaken to identify and characterize RNAs and proteins from phloem, including the profiling of RNA expression, proteomics, and screening techniques. The primary goal of this project is to elucidate the network of protein/RNA interactions that regulate tuber formation. Mechanisms that are uncovered have the potential for direct applications for enhancing crop productivity.


Photoperiod response in potato

Photoperiod-mediated response that activates a long-distance signal (white arrows) that moves from source leaves, via the phloem, to induce tuber formation in potato (Solanum tuberosum). In photoperiod-sensitive lines of potato, short days (less than 12 hours light) induce tuber formation whereas, long-day growth conditions (more than 12 hours light) inhibit tuberization.