Format

Send to

Choose Destination
Plant Cell. 2018 Dec;30(12):2959-2972. doi: 10.1105/tpc.18.00615. Epub 2018 Oct 29.

S-Locus F-Box Proteins Are Solely Responsible for S-RNase-Based Self-Incompatibility of Petunia Pollen.

Author information

1
Intercollege Graduate Degree Program in Plant Biology, Pennsylvania State University, University Park, Pennsylvania 16802.
2
Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802.
3
Intercollege Graduate Degree Program in Plant Biology, Pennsylvania State University, University Park, Pennsylvania 16802 txk3@psu.edu.

Abstract

Self-incompatibility (SI) in Petunia is regulated by a polymorphic S-locus. For each S-haplotype, the S-locus contains a pistil-specific S-RNase gene and multiple pollen-specific S-locus F-box (SLF) genes. Both gain-of-function and loss-of-function experiments have shown that S-RNase alone regulates pistil specificity in SI. Gain-of-function experiments on SLF genes suggest that the entire suite of encoded proteins constitute the pollen specificity determinant. However, clear-cut loss-of-function experiments must be performed to determine if SLF proteins are essential for SI of pollen. Here, we used CRISPR/Cas9 to generate two frame-shift indel alleles of S2 -SLF1 (SLF1 of S2 -haplotype) in S2S3 plants of P. inflata and examined the effect on the SI behavior of S2 pollen. In the absence of a functional S2-SLF1, S2 pollen was either rejected by or remained compatible with pistils carrying one of eight normally compatible S-haplotypes. All results are consistent with interaction relationships between the 17 SLF proteins of S2 -haplotype and these eight S-RNases that had been determined by gain-of-function experiments performed previously or in this work. Our loss-of-function results provide definitive evidence that SLF proteins are solely responsible for SI of pollen, and they reveal their diverse and complex interaction relationships with S-RNases to maintain SI while ensuring cross-compatibility.

PMID:
30377238
PMCID:
PMC6354264
DOI:
10.1105/tpc.18.00615
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for HighWire Icon for PubMed Central
Loading ...
Support Center