NSF Postdoctoral Fellowship in Biology

This action funds an NSF Plant Genome Postdoctoral Research Fellowship in Biology for FY 2022. The fellowship supports a research and training plan in a host laboratory for the Fellow who also presents a plan to broaden participation in biology. The title of the research and training plan for this fellowship to Paige M Henning is "Identification of the S-protein homolog (SPH) receptor proteins in Turnera subulata and high throughput initial characterization of the SPH family in Arabidopsis thaliana" The host institution for the fellowship is the University of Wisconsin Madison and the sponsoring scientist is Dr. Michael R Sussman.

Responsible use of genetic engineering has the potential to be highly beneficial for agriculture and human health, enabling improvements in crop yield and nutritional value. While genetically engineered crops have benefits, there are potential consequences. Escape of transgenic traits from transgenic into non-transgenic crops and wild plant populations being one of the most significant.

For example the passing of the herbicide resistance trait from transgenic corn to non-transgenic neighboring cornfields during reproduction. This is an economic, ecological and ethical problem, and it is our responsibility to take measures to prevent the spread of transgenic traits. One solution to prevent transgenic traits escaping is to prevent reproduction between transgenic and non-transgenic crops or wild species.

While this can be done with physical barriers , this approach is labor-intensive, expensive, and not applicable for all crop species. An alternative is to engineer a "reproductive" barriers. Essentially to remove the transgenic species' ability to mate with non-transgenic individuals of the same or related species.

To do so, we propose to emulate the naturally occurring barrier found in the reproductive system of the Cuban buttercup (Turnera subulata) in transgenic crops. To do this we need to thoroughly understand the genetic basis of this reproductive system. This research will use computational methods, genetics, and biochemistry to learn more about the Cuban buttercup's reproductive system.

Furthermore, this study will shed light on functions of a large family of signaling peptides that likely regulate diverse aspects of growth and development, using the model plant Arabidopsis thaliana.

Signaling peptides play varied and critical roles during stress responses as well as growth, reproductive, and developmental processes in the plant. A few signaling peptide families have been characterized, but an alarming number of families remain entirely uncharacterized. Characterizing signaling peptides may provide targets of interest to synthetic biology.

The S-protein homolog (SPH) signalling peptide family was initially identified in Papaver rhoeas. PrsS, the only characterized SPH, confers self-incompatibility in P. rhoeas. TsSPH1, identified at the self-incompatibility locus in distylous Turnera subulata, is predicted to modify anther placement within flowers by enhancing filament elongation, though the mechanism is unknown.

Expanding our knowledge of TsSPH1 will expand our understanding of the morphology and breakdown of distyly, an Angiosperm reproductive system that confers self-incompatibility. Aside from PrsS, the SPH family has not been investigated in any species, including the model dicot Arabidopsis thaliana. The goals of this project are 1.) to identify the receptor of TsSPH1, 2.) to determine if orthologs of this receptor are present in homostylous species of Turneroideae, 3.) to form hypotheses regarding the mode of action of TsSPH1, and 4.) begin the initial characterization of the SPH gene family in Arabidopsis using high throughput methods.

The characterization of the SPH gene family in Arabidopsis will allow researchers to form hypotheses regarding the roles of SPH family members in other organisms based on homology with Arabidopsis family members.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.