The Papaver Self-Incompatibility Pollen S-Determinant, PrpS, Functions in Arabidopsis thaliana

• Published in: Current biology Vol. 22; no. 2; pp. 154 - 159
• Main Authors: de Graaf, Barend H.J., Vatovec, Sabina, Juárez-Díaz, Javier Andrés, Chai, Lijun, Kooblall, Kreepa, Wilkins, Katie A., Zou, Huawen, Forbes, Thomas, Franklin, F. Christopher H., Franklin-Tong, Vernonica E.
• Format: Journal Article
• Language: English
• Published: England Elsevier Inc 24.01.2012; Cell Press
• Subjects: Actins - metabolism; apoptosis; Arabidopsis - physiology; Arabidopsis thaliana; biologists; Caspase 3 - metabolism; Cell Death; cytoskeleton; evolution; genes; genetically modified organisms; loci; Papaver - genetics; Papaver rhoeas; Peptide Hydrolases - metabolism; pistil; Plant Proteins - metabolism; pollen; Pollen - metabolism; pollen tubes; proteins; Self-Incompatibility in Flowering Plants - genetics; selfing
• ISSN: 0960-9822; 1879-0445
• DOI: 10.1016/j.cub.2011.12.006

Many angiosperms use specific interactions between pollen and pistil proteins as “self” recognition and/or rejection mechanisms to prevent self-fertilization. Self-incompatibility (SI) is encoded by a multiallelic S locus, comprising pollen and pistil S-determinants [1, 2]. In Papaver rhoeas, cognate pistil and pollen S-determinants, PrpS, a pollen-expressed transmembrane protein, and PrsS, a pistil-expressed secreted protein [3, 4], interact to trigger a Ca2+-dependent signaling network [5–10], resulting in inhibition of pollen tube growth, cytoskeletal alterations [11–13], and programmed cell death (PCD) [14, 15] in incompatible pollen. We introduced the PrpS gene into Arabidopsis thaliana, a self-compatible model plant. Exposing transgenic A. thaliana pollen to recombinant Papaver PrsS protein triggered remarkably similar responses to those observed in incompatible Papaver pollen: S-specific inhibition and hallmark features of Papaver SI [11–15]. Our findings demonstrate that Papaver PrpS is functional in a species with no SI system that diverged ∼140 million years ago [16]. This suggests that the Papaver SI system uses cellular targets that are, perhaps, common to all eudicots and that endogenous signaling components can be recruited to elicit a response that most likely never operated in this species. This will be of interest to biologists interested in the evolution of signaling networks in higher plants. ► PrpS, a Papaver SI determinant, functions in Arabidopsis thaliana pollen ► A “self” interaction with PrsS reveals Papaver SI hallmark features in A. thaliana ► The first evidence for transfamily functionality of an SI system (>140 my apart) ► Evidence of recruitment of signaling components for novel SI function