Molecular and genetic characterization of a self-compatible apple cultivar, 'CAU-1'
Molecular and genetic characterization of a self-compatible apple cultivar, 'CAU-1'
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自交亲和苹果品种“CAU-1”的分子和遗传特征
DOI：
10.1016/j.plantsci.2016.07.010
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发表时间：
2016-11-01
期刊：
影响因子：
5.2
通讯作者：
Li, Tianzhong
中科院分区：
文献类型：
--
作者：
Li, Wei;Yang, Qing;Li, Tianzhong
在这项研究中，我们描述了一种自然发生的自交亲和苹果品种“CAU-1”（S1S9），并研究了导致其相容性的潜在机制。对自花授粉或与“富士”(S1S9)异花授粉后的坐果率和种子数以及花粉管生长的分析表明，“CAU-1”是自交亲和的。通过对“CAU-1”自交后代进行 S-RNase PCR 分型进行的遗传分析揭示了所有后代类别（S1S1、S1S9 和 S9S9）的存在。此外，没有发现S等位基因重复的证据。这些发现支持这样的假设：花粉中表达的 S 位点非连锁花粉部分突变 (PPM) 的功能丧失，而不是花粉-S 基因（S-1- 和 S-9- 单倍型）的自然突变，导致“CAU-1”中 SI 崩溃。此外，'富士'和'CAU-1'之间的花粉形态或育性没有显着差异。然而，我们发现 S-1- 和 S-9-RNase 对花粉 SI 行为的影响在“CAU-1”中不能比在“Fuji”中得到更好的解决。此外，我们发现花粉表达的己糖转运蛋白 MdHT1 与 S-RNase 相互作用，并且在“CAU-1”中的表达显着低于“Fuji”花粉管中的表达。这些结果支持了以下假设：MdHT1可能参与SI过程中的S-RNase内化，并且'CAU-1'中MdHT1表达的减少阻碍了自身S-RNase释放到花粉管细胞质中，从而保护花粉免受S-RNase的细胞毒性，最终可能导致自交亲和。总之，这些发现表明 S 基因座外部因素是蔷薇科 Pyrinae 亚族配子体 SI 所必需的。 (C) 2016 Elsevier Ireland Ltd. 保留所有权利。
In this study, we characterized a naturally occurring self-compatible apple cultivar, 'CAU-1' (S1S9), and studied the underlying mechanism that causes its compatibility. Analyses of both fruit set rate and seed number after self-pollination or cross-pollination with 'Fuji' (S1S9), and of pollen tube growth, demon-strated that 'CAU-1' is self-compatible. Genetic analysis by S-RNase PCR-typing of selfed progeny of 'CAU-1' revealed the presence of all progeny classes (S1S1, S1S9, and S9S9). Moreover, no evidence of S-allele duplication was found. These findings support the hypothesis that loss of function of an S-locus unlinked pollen-part mutation (PPM) expressed in pollen, rather than a natural mutation in the pollen-S gene (S-1- and S-9- haplotype), leads to SI breakdown in 'CAU-1'. In addition, there were no significant differences in pollen morphology or fertility between 'Fuji' and 'CAU-1'. However, we found that the effect of S-1- and S-9-RNase on the SI behavior of pollen could not be addressed better in 'CAU-1' than in 'Fuji'. Furthermore, we found that a pollen-expressed hexose transporter, MdHT1, interacted with S-RNases and showed significantly less expression in 'CAU-1' than in 'Fuji' pollen tubes. These findings support the hypothesis that MdHT1 may participate in S-RNase internalization during the SI process, and decrease of MdHT1 expression in 'CAU-1' hindered the release of self S-RNase into the cytoplasm of pollen tubes, thereby protecting pollen from the cytotoxicity of S-RNase, finally probably resulting in self-compatibility. Together, these findings indicate that S-locus external factors are required for gametophytic SI in the Rosaceae subtribe Pyrinae. (C) 2016 Elsevier Ireland Ltd. All rights reserved.