Collaborative non-self recognition system in S-RNase-based self-incompatibility.
Self-incompatibility in flowering plants prevents inbreeding and promotes outcrossing to generate genetic diversity. In Solanaceae, a multiallelic gene, S-locus F-box (SLF), was previously shown to encode the pollen determinant in self-incompatibility. It was postulated that an SLF allelic product specifically detoxifies its non-self S-ribonucleases (S-RNases), allelic products of the pistil determinant, inside pollen tubes via the ubiquitin-26S-proteasome system, thereby allowing compatible pollinations. However, it remained puzzling how SLF, with much lower allelic sequence diversity than S-RNase, might have the capacity to recognize a large repertoire of non-self S-RNases. We used in vivo functional assays and protein interaction assays to show that in Petunia, at least three types of divergent SLF proteins function as the pollen determinant, each recognizing a subset of non-self S-RNases. Our findings reveal a collaborative non-self recognition system in plants.
Graduate School of Biological Sciences, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma 630-0192, Japan.
Ken-ichi
K
Kubo
Tetsuyuki
T
Entani
Akie
A
Takara
Ning
N
Wang
Allison M
AM
Fields
Zhihua
Z
Hua
Mamiko
M
Toyoda
Shin-ichi
S
Kawashima
Toshio
T
Ando
Akira
A
Isogai
Teh-hui
TH
Kao
Seiji
S
Takayama
D000483:Alleles; D000595:Amino Acid Sequence; D003433:Crosses, Genetic; D044783:F-Box Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D035264:Flowers / Q000235:genetics / Q000502:physiology; D020869:Gene Expression Profiling; D017343:Genes, Plant; D014644:Genetic Variation; D006239:Haplotypes; D008957:Models, Genetic; D008969:Molecular Sequence Data; D032306:Petunia / Q000235:genetics* / Q000502:physiology*; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D030821:Plants, Genetically Modified; D011058:Pollen / Q000235:genetics* / Q000502:physiology*; D053205:Pollen Tube / Q000502:physiology; D054817:Pollination; D025941:Protein Interaction Mapping; D012260:Ribonucleases / Q000235:genetics / Q000378:metabolism*; D057945:Self-Fertilization; D019076:Transgenes
D044783:F-Box Proteins; D010940:Plant Proteins; D012260:Ribonucleases