Transcriptomic analysis links gene expression to unilateral pollen-pistil reproductive barriers.
Transcriptomic analysis links gene expression to unilateral pollen-pistil reproductive barriers.
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DOI：
10.1186/s12870-017-1032-4
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发表时间：
2017-04-24
影响因子：
5.3
通讯作者：
Bedinger PA
中科院分区：
文献类型：
--
作者：
Broz AK;Guerrero RF;Randle AM;Baek YS;Hahn MW;Bedinger PA
单边不亲和性(UI)是一种不对称的生殖障碍，它单向地阻止物种和/或种群之间的基因流动。UI的特征是在一个方向上伴侣之间的相互作用是相容的，但在双向杂交中失败，通常是由于雌蕊对花粉管的排斥。尽管在不同物种之间的杂交中观察到UI很久了，但其潜在的分子机制才刚刚开始被表征。野生番茄近缘种茄子提供了一个独特的研究系统来研究这种生殖障碍的分子基础，因为该物种内的种群既表现出种间UI，也表现出种群间UI。在这里，我们利用转录转录方法来鉴定花粉和雌蕊组织中可能在UI中起关键作用的基因。我们在自交不亲和群体和自交亲和群体之间的花粉-雌蕊水平上证实了UI。对表现不亲和性反应的授粉花柱和未授粉对照之间的基因表达进行比较，发现只有少量差异表达的转录本。在UI功能正常的生殖组织和UI受损的生殖组织之间，发现了更多的转录谱差异。许多有趣的候选基因高度差异表达，包括推测的花粉阿拉伯半乳糖蛋白，花柱昆尼茨家族的蛋白酶抑制因子，以及花柱多肽激素快速碱化因子。我们的数据还提供了转录学证据，表明包括活性氧(ROS)信号在内的基本过程可能在种群和物种之间的UI花粉-雌蕊相互作用中起关键作用。生殖组织的基因表达分析使我们能够在花粉-雌蕊互作水平上更好地理解种群间不亲和性的分子基础。我们的转录分析强调了特定的基因，包括那些在ROS信号通路中的基因，这些基因值得在UI的研究中进一步研究。据我们所知，这是第一次发现与物种内种群之间的单边障碍有关的候选基因。本文的在线版本(doi：10.1186/s12870-0171032-4)包含补充材料，授权用户可以使用。
Unilateral incompatibility (UI) is an asymmetric reproductive barrier that unidirectionally prevents gene flow between species and/or populations. UI is characterized by a compatible interaction between partners in one direction, but in the reciprocal cross fertilization fails, generally due to pollen tube rejection by the pistil. Although UI has long been observed in crosses between different species, the underlying molecular mechanisms are only beginning to be characterized. The wild tomato relative Solanum habrochaites provides a unique study system to investigate the molecular basis of this reproductive barrier, as populations within the species exhibit both interspecific and interpopulation UI. Here we utilized a transcriptomic approach to identify genes in both pollen and pistil tissues that may be key players in UI. We confirmed UI at the pollen-pistil level between a self-incompatible population and a self-compatible population of S. habrochaites. A comparison of gene expression between pollinated styles exhibiting the incompatibility response and unpollinated controls revealed only a small number of differentially expressed transcripts. Many more differences in transcript profiles were identified between UI-competent versus UI-compromised reproductive tissues. A number of intriguing candidate genes were highly differentially expressed, including a putative pollen arabinogalactan protein, a stylar Kunitz family protease inhibitor, and a stylar peptide hormone Rapid ALkalinization Factor. Our data also provide transcriptomic evidence that fundamental processes including reactive oxygen species (ROS) signaling are likely key in UI pollen-pistil interactions between both populations and species. Gene expression analysis of reproductive tissues allowed us to better understand the molecular basis of interpopulation incompatibility at the level of pollen-pistil interactions. Our transcriptomic analysis highlighted specific genes, including those in ROS signaling pathways that warrant further study in investigations of UI. To our knowledge, this is the first report to identify candidate genes involved in unilateral barriers between populations within a species. The online version of this article (doi:10.1186/s12870-017-1032-4) contains supplementary material, which is available to authorized users.