Comparative De Novo Transcriptome Analysis of Fertilized Ovules in Xanthoceras sorbifolium Uncovered a Pool of Genes Expressed Specifically or Preferentially in the Selfed Ovule That Are Potentially Involved in Late-Acting Self-Incompatibility.
Comparative De Novo Transcriptome Analysis of Fertilized Ovules in Xanthoceras sorbifolium Uncovered a Pool of Genes Expressed Specifically or Preferentially in the Selfed Ovule That Are Potentially Involved in Late-Acting Self-Incompatibility.
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对文冠果受精胚珠的比较从头转录组分析发现了一组在自交胚珠中特异性或优先表达的基因，这些基因可能与晚效自交不亲和性有关
DOI：
10.1371/journal.pone.0140507
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发表时间：
2015
期刊：
影响因子：
3.7
通讯作者：
Zheng Y
中科院分区：
文献类型：
--
作者：
Zhou Q;Zheng Y
文冠果是我国北方特有的树种，其种子含油量高，是公认的重要生物柴油作物。该植物具有迟效自交不亲和性（LSI）。LSI被发现存在于许多被子植物物种中，并且在减少近亲繁殖及其有害影响方面起着重要作用，配子体自交不亲和性（GSI）和孢子体自交不亲和性（SSI）也是如此。传统的GSI和SSI的分子机制已经在几个家庭中得到了很好的表征，但还没有努力确定参与LSI过程的基因。本研究表明，自花授粉和异花授粉胚珠在胚珠发育的早期至授粉后5天（DAP），其结构和组织学特征没有显著差异。这表明，5 DAP可能是自交胚珠发育的转折点。比较从头转录组分析的自交和杂交胚珠在5 DAP确定了274个基因的表达特异性或优先在自交胚珠。这些基因中含有相当大比例的预测在次生代谢产物的生物合成中起作用的基因，这与我们在受精胚珠中的组织学观察结果一致。编码信号转导相关成分的基因，如蛋白激酶和蛋白磷酸酶，在自交胚珠中大量存在。X.花楸自交胚珠也特异或优先表达许多独特的转录因子（TF）基因，这些基因可能参与LSI的新机制。我们还确定了42个基因显着上调杂交胚珠相比，自交胚珠。在自交和杂交胚珠中使用PCR验证从RNA-seq数据中选择的所有16个基因的表达。这项研究代表了LSI物种受精胚珠中表达的基因的第一个全基因组鉴定。从X的自交胚珠特异或优先表达的基因池的可用性。山梨叶将是一个宝贵的资源，为未来的遗传分析候选基因参与LSI的反应。
Xanthoceras sorbifolium, a tree species endemic to northern China, has high oil content in its seeds and is recognized as an important biodiesel crop. The plant is characterized by late-acting self-incompatibility (LSI). LSI was found to occur in many angiosperm species and plays an important role in reducing inbreeding and its harmful effects, as do gametophytic self-incompatibility (GSI) and sporophytic self-incompatibility (SSI). Molecular mechanisms of conventional GSI and SSI have been well characterized in several families, but no effort has been made to identify the genes involved in the LSI process. The present studies indicated that there were no significant differences in structural and histological features between the self- and cross-pollinated ovules during the early stages of ovule development until 5 days after pollination (DAP). This suggests that 5 DAP is likely to be a turning point for the development of the selfed ovules. Comparative de novo transcriptome analysis of the selfed and crossed ovules at 5 DAP identified 274 genes expressed specifically or preferentially in the selfed ovules. These genes contained a significant proportion of genes predicted to function in the biosynthesis of secondary metabolites, consistent with our histological observations in the fertilized ovules. The genes encoding signal transduction-related components, such as protein kinases and protein phosphatases, are overrepresented in the selfed ovules. X. sorbifolium selfed ovules also specifically or preferentially express many unique transcription factor (TF) genes that could potentially be involved in the novel mechanisms of LSI. We also identified 42 genes significantly up-regulated in the crossed ovules compared to the selfed ovules. The expression of all 16 genes selected from the RNA-seq data was validated using PCR in the selfed and crossed ovules. This study represents the first genome-wide identification of genes expressed in the fertilized ovules of an LSI species. The availability of a pool of specifically or preferentially expressed genes from selfed ovules for X. sorbifolium will be a valuable resource for future genetic analyses of candidate genes involved in the LSI response.