Potato StCDF1: A Master Regulator for Potato Tuber Development

Potato plants produce tubers as storage organs and as a means of bridging periods of adverse environmental conditions such as winter or seasonal dry periods. Accordingly, potato regulates the timing of tuberisation using environmental cues. An important pathway for this regulation is the photoperiodic pathway that has been recently elucidated and comprises the clock output Proteins StGI and StFKF that post-transcriptionally regulate the transcription factor StCDF1. This DOF transcription factor in turn regulates expression of StCO genes and their downstream partners StSP5G and StSP6A.  StSP6A is thus indirectly induced by StCDF1 and is the mobile tuberigen that initiates tuberisation at the stolon tip. We have now further elucidated the action of StCDF1 in binding the new identified triple tandem repeat of StCO genes and will present these finding together with new results suggesting that StCDF1 is a master regulator of other StCDF genes. We suggest that these StCDF proteins may be the basis for the sensing of a number of other environmental cues that influences timing of tuberisation. Furthermore, we are investigating how environmental stress conditions can actually suppress tuberisation and are working to discover the intersection points between the now well-elucidated regulatory network of tuberisation and abiotic stress factors.