The S-locus receptor kinase SRK was initially identified as the stigma epidermal cell receptor that is activated by its cognate pollen coat-localized SCR ligand and is responsible for perception of 'self' pollen in the self-incompatibility (SI) response. Recently, mutagenesis of the SI response in a transgenic Arabidopsis thaliana self-incompatible model developed in the investigators' laboratory demonstrated that SRK also functions as a signaling molecule in pistil development, where its SCR-independent activity promotes cell proliferation in style and ovary, thus enhancing pistil elongation and causing stigma exsertion. The project will use molecular and genetic methods to investigate the tight integration of the cell-to-cell interactions that underlie rejection of 'self' pollen in SI with the overall pistil developmental program. The study is expected to identify genes required for a cell's competence for SRK signaling, genes responsible for cross-talk between pollen-stigma interactions and pistil elongation, and possibly genes encoding components of the SRK signaling cascade. The project has the potential to alter current views of SRK-mediated signaling, the evolution of SI, and the poorly-understood association between SI and morphological adaptations that promote out-breeding, such as stigma exsertion. More generally, the study will contribute to answering the key question of how organisms modify their developmental programs to generate novel designs in structure and function.
The project will train post-doctoral researchers and provide them with opportunities to integrate teaching and research, within the highly-interactive and intellectually stimulating Cornell environment. The PIs are committed to providing undergraduate students with research experience and training in basic methods of plant molecular genetics, both within the framework of NSF-funded projects and in formal coursework. Their participation in 'Lab Experience for Teachers', a course designed for Masters students training to become science teachers should also contribute to the transfer of scientific knowledge into elementary and high schools.
