Repositorium
A farnesyl pyrophosphate synthase gene expressed in pollen functions in S -RNase-independent unilateral incompatibility
338
Journal Article / 2018
Qin, Xiaoqiong; Li, Wentao; Liu, Yang; Tan, Meilian; Ganal, Martin; Chetelat, Roger T.
Multiple independent and overlapping pollen rejection pathways contribute to unilateral interspecific incompatibility (UI). In crosses between tomato species, pollen rejection usually occurs when the female parent is self-incompatible (SI) and the male parent self-compatible (SC) (the ‘SI 3 SC rule’). Additional, as yet unknown, UI mechanisms are independent of self-incompatibility and contribute to UI between SC species or populations. We identified a major quantitative trait locus on chromosome 10 (ui10.1) which affects pollen-side UI responses in crosses between cultivated tomato, Solanum lycopersicum, and Solanum pennellii LA0716, both of which are SC and lack S-RNase, the pistil determinant of S-specificity in Solanaceae. Here we show that ui10.1 is a farnesyl pyrophosphate synthase gene (FPS2) expressed in pollen. Expression is about 18-fold higher in pollen of S. pennellii than in S. lycopersicum. Pollen with the hypomorphic S. lycopersicum allele is selectively eliminated on pistils of the F1 hybrid, leading to transmission ratio distortion in the F2 progeny. CRISPR/Cas9-generated knockout mutants (fps2)in S. pennellii LA0716 are self-sterile due to pollen rejection, but mutant pollen is fully functional on pistils of S. lycopersicum.F2 progeny of S. lycopersicum 3 S. pennellii (fps2) show reversed transmission ratio distortion due to selective elimination of pollen bearing the knockout allele. Overexpression of FPS2 in S. lycopersicum pollen rescues the pollen elimination phenotype. FPS2-based pollen selectivity does not involve S-RNase and has not been previously linked to UI. Our results point to an entirely new mechanism of interspecific pollen rejection in plants.
Techniques
ID | Corresponding Author Country |
Plant Species | GE Technique Sequence Identifier |
Trait Type of Alteration |
Progress in Research Key Topic |
---|---|---|---|---|---|
794 |
Chetelat, Roger T. USA |
Solanum pimpinellifolium |
CRISPR/Cas9 fps2 |
Pollen sterility SDN1 |
Basic research Basic research |
795 |
Chetelat, Roger T. USA |
Solanum pimpinellifolium |
CRISPR/Cas9 CWC15 |
Abundant fruits and seeds by spontaneous self-pollination SDN1 |
Basic research Basic research |