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Structural and transcriptional analysis of the self-incompatibility locus of almond: identification of a pollen-expressed F-box gene with haplotype-specific polymorphism. Plant Cell

Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan.
The Plant Cell (Impact Factor: 9.34). 04/2003; 15(3):771-81.
Source: PubMed

ABSTRACT

Gametophytic self-incompatibility in Rosaceae, Solanaceae, and Scrophulariaceae is controlled by the S locus, which consists of an S-RNase gene and an unidentified "pollen S" gene. An approximately 70-kb segment of the S locus of the rosaceous species almond, the S haplotype-specific region containing the S-RNase gene, was sequenced completely. This region was found to contain two pollen-expressed F-box genes that are likely candidates for pollen S genes. One of them, named SFB (S haplotype-specific F-box protein), was expressed specifically in pollen and showed a high level of S haplotype-specific sequence polymorphism, comparable to that of the S-RNases. The other is unlikely to determine the S specificity of pollen because it showed little allelic sequence polymorphism and was expressed also in pistil. Three other S haplotypes were cloned, and the pollen-expressed genes were physically mapped. In all four cases, SFBs were linked physically to the S-RNase genes and were located at the S haplotype-specific region, where recombination is believed to be suppressed, suggesting that the two genes are inherited as a unit. These features are consistent with the hypothesis that SFB is the pollen S gene. This hypothesis predicts the involvement of the ubiquitin/26S proteasome proteolytic pathway in the RNase-based gametophytic self-incompatibility system.

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Available from: Ryutaro Tao, May 20, 2015
    • "& Zucc. (Entani et al., 2003), almond (Ushijima et al., 2003), and sweet cherry (Yamane et al., 2003a), showing a tight linkage with the S-RNase gene (Ikeda et al., 2004Ikeda et al., , 2005). The examination of the different S haplotypes in Rosaceous fruit trees was extensively undertaken by Yamane and Tao (2009). "
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    ABSTRACT: Self-incompatible Prunus species show a gametophytic self-incompatibility system, but self-compatibility is an interesting horticultural trait in these fruit tree species. Self-compatibility has recently attracted a particular attention since molecular approaches have been applied to the elucidation of the interacting pollen–pistil mechanism and to the identification of the genes involved in pistil–pollen recognition. Both mutations of the S-RNase gene expressed in the pistil and the SFB gene expressed in the pollen have been reported to explain breakdown of the incompatibility system in Prunus. Stylar-part mutations have revealed that ribonuclease activity of the S-RNases is required to inhibit pollen growth and have shown different activity levels for some S-RNases. The self-compatibility observed in some cultivars has been reported to be due to a defective pollen S-function, such as in sweet cherry, apricot, Japanese apricot and peach. Breakdown of self-incompatibility has also been associated with mutations affecting modifier genes unlinked to the S-locus, such as in sweet cherry, apricot, Japanese plum, and almond. Additionally, a double phenotypic expression of the same S-genotype has been observed in Japanese plum, sweet cherry and almond. The nature of these different mutations has only been identified in a few cases, including deletions, insertions, shift mutations and, more recently, epigenetic alterations.
    No preview · Article · Aug 2015 · Scientia Horticulturae
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    • "Webb). In these species, the pistil-S determinant is a single ribonuclease (S-RNase) and the pollen-S determinant is a protein encoded by a single S haplotype-specific F-box gene (SFB) (Entani et al. 2003, Ushijima et al. 2003, Yamane et al. 2003). It has been hypothesized that a general inactivation mechanism detoxifies non-self S-RNases, whereas SFB protects self S-RNase (Sonneveld et al. 2005). "
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    ABSTRACT: Gametophytic self-incompatibility in Japanese pear (Pyrus pyrifolia Nakai) is controlled by the single, multi-allelic S-locus. Information about the S-genotypes is important for breeding and the selection of pollen donors for fruit production. Rapid and reliable S-genotype identification system is necessary for efficient breeding of new cultivars in Japanese pear. We designed S allele-specific PCR primer pairs for ten previously reported S-RNase alleles (S (1)-S (9) and S (k)) as simple and reliable method. Specific nucleotide sequences were chosen to design the primers to amplify fragments of only the corresponding S alleles. The developed primer pairs were evaluated by using homozygous S-genotypes (S (1)/S (1)-S (9)/S (9) and S (4sm)/S (4sm)) and 14 major Japanese pear cultivars, and found that S allele-specific primer pairs can identify S-genotypes effectively. The S allele-specific primer pairs developed in this study will be useful for efficient S-genotyping and for marker-assisted selection in Japanese pear breeding programs.
    Full-text · Article · Jun 2015 · Breeding Science
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    • "avium L.; Ushijima et al., 2004) and plum (P. mume Siebold & Zucc.; Ushijima et al., 2003; Yamane et al., 2003). Later, a transformation experiment showed that an F-box protein gene, called SLF for the S locus F-box gene, was the pollen S in Putunia inflata (Solanaceae) (Sijacic et al., 2004). "

    Full-text · Article · Jan 2015 · Acta horticulturae
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