Apple Research Station, NARO Institute of Fruit Tree Science, Morioka, Iwate, 020-0123, Japan.
Plant Reprod. 2013 Jun;26(2):101-11. doi: 10.1007/s00497-013-0212-0. Epub 2013 Feb 12.
Using 11 consensus primer pairs designed from S-linked F-box genes of apple and Japanese pear, 10 new F-box genes (MdFBX21 to 30) were isolated from the apple cultivar 'Spartan' (S(9)S(10)). MdFBX21 to 23 and MdFBX24 to 30 were completely linked to the S(9) -RNase and S(10-)RNase, respectively, and showed pollen-specific expression and S-haplotype-specific polymorphisms. Therefore, these 10 F-box genes are good candidates for the pollen determinant of self-incompatibility in apple. Phylogenetic analysis and comparison of deduced amino acid sequences of MdFBX21 to 30 with those of 25 S-linked F-box genes previously isolated from apple showed that a deduced amino acid identity of greater than 88.0 % can be used as the tentative criterion to classify F-box genes into one type. Using this criterion, 31 of 35 F-box genes of apple were classified into 11 types (SFBB1-11). All types included F-box genes derived from S(3-) and S(9-)haplotypes, and seven types included F-box genes derived from S(3-), S(9-), and S(10-)haplotypes. Moreover, comparison of nucleotide sequences of S-RNases and multiple F-box genes among S(3-), S(9-), and S(10-)haplotypes suggested that F-box genes within each type showed high nucleotide identity regardless of the identity of the S-RNase. The large number of F-box genes as candidates for the pollen determinant and the high degree of conservation within each type are consistent with the collaborative non-self-recognition model reported for Petunia. These findings support that the collaborative non-self-recognition system also exists in apple.
利用从苹果和日本梨的 S 连接 F-box 基因设计的 11 个共识引物对，从苹果品种“斯巴达”（S(9)S(10)）中分离出 10 个新的 F-box 基因（MdFBX21 至 30）。MdFBX21 至 23 和 MdFBX24 至 30 分别与 S(9)-RNase 和 S(10)-RNase 完全连锁，并表现出花粉特异性表达和 S 单倍型特异性多态性。因此，这 10 个 F-box 基因是苹果自交不亲和花粉决定因子的良好候选基因。MdFBX21 至 30 的系统发育分析和推导氨基酸序列与先前从苹果中分离的 25 个 S 连接 F-box 基因的比较表明，大于 88.0%的推导氨基酸同一性可作为将 F-box 基因分类为一种类型的暂定标准。使用此标准，苹果的 35 个 F-box 基因中的 31 个被分类为 11 种类型（SFBB1-11）。所有类型都包括来自 S(3-)和 S(9-)单倍型的 F-box 基因，7 种类型包括来自 S(3-)、S(9-)和 S(10-)单倍型的 F-box 基因。此外，对 S-RNase 和多个 F-box 基因在 S(3-)、S(9-)和 S(10-)单倍型中的核苷酸序列的比较表明，无论 S-RNase 的身份如何，每个类型内的 F-box 基因都显示出高度的核苷酸同一性。作为花粉决定因子候选基因的大量 F-box 基因和每个类型内的高度保守性与已报道的 Petunia 中的协作非自我识别模型一致。这些发现支持协作非自我识别系统也存在于苹果中。
