| Popis: |
Self-incompatibility is adopted by many flowering plants to prevent inbreeding, and is controlled by a multi-allelic \(S\)-locus. In \(Papaver\) \(rhoeas\), the pistil \(S\)-determinant is PrsS (a small secreted protein); the pollen \(S\)-determinant is PrpS (a novel transmembrane protein). Cognate PrpS-PrsS interaction induces DEVDase-mediated programmed cell death of incompatible pollen. Here, we examined the role of proteasome during the \(Papaver\) SI response and showed that the proteasome is a target of the \(Papaver\) SI response, and is distinct from the SI-induced DEVDase activity. Our main focus here is translational work, attempting to move the Papaver SI system into \(A\). \(thaliana\). We previously demonstrated that PrpS:GFP expressed in \(A\). \(thaliana\) pollen was functional \(in\) \(vitro\). Here, we expressed the female \(S\)-determinant, PrsS, in \(A\). \(thaliana\) and investigated function \(in\) \(vivo\). We present data demonstrating that transgenic A. thaliana stigmas expressing PrsS pollinated with \(A\). \(thaliana\) pollen expressing PrpS:GFP inhibited pollen tube growth in an S-specific manner, and virtually no seed was set. Transformation of both \(PrpS\)\(:\)\(GFP\) and \(PrsS\) into \(A\). \(thaliana\) generated self-incompatible plants that set no self-seed. This demonstrates that transfer of the \(Papaver\) SI system into a highly diverged self-compatible species can result in a fully functional SI system. |
