A ctin depolymerization is a death trigger for poppy pollen, according to Thomas et al. (page 221), that prevents self-fertilization. Some plants prefer not to be fertilized by pollen grains that are genetically similar to themselves. These plants express self-incompatibility (S) proteins. A match between the pistil’s S-proteins and the pollen’s S-allele triggers a rapid calcium infl ux, actin ...

Self-incompatibility systems in plants are genetic systems that prevent self-fertilization in hermaphrodites through recognition and rejection of pollen expressing the same allelic specificity as that expressed in the pistils. The evolutionary properties of these self-recognition systems have been revealed through a fascinating interplay between empirical advances and theoretical developments. ...

The self-incompatibility mechanism that reduces inbreeding in many plants of the Rosaceae is attributed to a multi-allelic S locus which, in the Prunoideae and Maloideae subfamilies, comprises two complementary genes, a stylar-expressed S-RNase and a pollen-expressed SFB. To elucidate incompatibility in the subfamily Rosoideae, stylar-specific RNases and self-(in)compatibility status were analy...

Breakdown of self-incompatibility occurs repeatedly in flowering plants with important evolutionary consequences. In plant families in which self-incompatibility is mediated by S-RNases, previous evidence suggests that polyploidy may often directly cause self-compatibility through the formation of diploid pollen grains. We use three approaches to examine relationships between self-incompatibili...

Whitehouse (1950): 1. Sudden rise of angiosperms during the Cretaceous period (144-65 million years ago) was due to the development of barriers for self-pollination forcing the flowering plants to out breed and resulted genetic variations and rapid expansion of the angiosperms. 2. 70% of the angiosperms are hermophrodite species, while no more than 5% dioecious. Such a high proportion of hermop...

Self-fertilization, which results in reduced fitness of offspring, is a common problem in hermaphrodite angiosperms. To prevent this, many plants utilize self-incompatibility (SI), which is determined by the multi-allelic S locus, that allows discrimination between self (incompatible) and non-self (compatible) pollen by the pistil. In poppy (Papaver rhoeas), the pistil S-determinant (PrsS) is a...

In the January issue of New Phytologist Vallejo-Marín and O'Brien1 documented that in the genus Solanum (Solanaceae) clonality and self-incompatibility, a common genetic mechanism enforcing cross-fertilization, co-occur more often than expected by chance. Using a phylogenetic approach the authors showed that the statistical association between clonality and self-incompatibility persists even af...

Following the identification of the male (S-locus Cysteine Rich/S-locus Protein 11) and female (S Receptor kinase [SRK]) factors controlling self-incompatibility in the Brassicaceae, research in this field has focused on understanding the nature of the cellular responses activated by these regulators. We previously identified the ARM Repeat Containing1 (ARC1) E3 ligase as a component of the SRK...