Quantitative proteomics of the tobacco pollen tube secretome identifies novel pollen tube guidance proteins important for fertilization.
Quantitative proteomics of the tobacco pollen tube secretome identifies novel pollen tube guidance proteins important for fertilization.
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DOI：
10.1186/s13059-016-0928-x
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发表时间：
2016-05-03
期刊：
影响因子：
12.3
通讯作者：
Honys D
中科院分区：
文献类型：
--
作者：
Hafidh S;Potěšil D;Fíla J;Čapková V;Zdráhal Z;Honys D
与动物一样，细胞间的通讯在植物有性生殖过程中的雄性-雌性识别中发挥着关键作用。从雌性生殖组织分泌的预制肽将花粉管引导至胚珠进行受精。然而，这种对话的复杂机制仍然难以捉摸，特别是从男性的角度来看。我们对雌蕊刺激的花粉管分泌蛋白组进行了全基因组定量液相色谱-串联质谱分析，并鉴定了 801 种花粉管分泌蛋白。有趣的是，计算机分析表明，花粉管分泌蛋白组以非常规分泌的蛋白质为主，占总分泌蛋白组的 57%。作为支持，我们证明了一种非常规分泌的蛋白质，即翻译控制的肿瘤蛋白，被分泌到质外体中。值得注意的是，我们发现该蛋白可以通过常规分泌途径的初始阶段渗透来分泌，并且可以通过外泌体到达质外体，如与 Oleisin1 外泌体标记物的共定位所证明的。我们证明翻译控制的肿瘤蛋白敲低拟南芥植物产生的花粉管很难导航到目标胚珠，并且突变等位基因很难通过雄性传播。 此外，我们还发现内质网-反高尔基体网络蛋白分泌途径的调节因子控制着烟草花粉管分泌的富含半胱氨酸的蛋白2和Lorelei样GPI锚定蛋白3的分泌，并且内质网-反高尔基体蛋白易位的调节因子对于花粉管生长、花粉管引导至关重要。 和胚珠靶向能力。这项工作是第一项关于花粉管分泌组的研究，鉴定了新型全基因组花粉管分泌蛋白，其在花粉管引导有性生殖胚珠方面具有潜在功能。功能分析强调了花粉管蛋白非常规分泌的潜在机制，并揭示了常规花粉管蛋白分泌的可能调节因子。花粉管分泌蛋白与其他物种中通过外泌体分泌的标记蛋白的关联表明，外泌体分泌是花粉管和雌性生殖细胞之间细胞间通讯的可能机制。本文的在线版本 (doi:10.1186/s13059-016-0928-x) 包含补充材料，可供授权用户使用。
As in animals, cell–cell communication plays a pivotal role in male–female recognition during plant sexual reproduction. Prelaid peptides secreted from the female reproductive tissues guide pollen tubes towards ovules for fertilization. However, the elaborate mechanisms for this dialogue have remained elusive, particularly from the male perspective. We performed genome-wide quantitative liquid chromatography–tandem mass spectrometry analysis of a pistil-stimulated pollen tube secretome and identified 801 pollen tube-secreted proteins. Interestingly, in silico analysis reveals that the pollen tube secretome is dominated by proteins that are secreted unconventionally, representing 57 % of the total secretome. In support, we show that an unconventionally secreted protein, translationally controlled tumor protein, is secreted to the apoplast. Remarkably, we discovered that this protein could be secreted by infiltrating through the initial phases of the conventional secretory pathway and could reach the apoplast via exosomes, as demonstrated by co-localization with Oleisin1 exosome marker. We demonstrate that translationally controlled tumor protein-knockdown Arabidopsis thaliana plants produce pollen tubes that navigate poorly to the target ovule and that the mutant allele is poorly transmitted through the male. Further, we show that regulators of the endoplasmic reticulum–trans-Golgi network protein secretory pathway control secretion of Nicotiana tabacum Pollen tube-secreted cysteine-rich protein 2 and Lorelei-like GPI-anchor protein 3 and that a regulator of endoplasmic reticulum–trans-Golgi protein translocation is essential for pollen tube growth, pollen tube guidance and ovule-targeting competence. This work, the first study on the pollen tube secretome, identifies novel genome-wide pollen tube-secreted proteins with potential functions in pollen tube guidance towards ovules for sexual reproduction. Functional analysis highlights a potential mechanism for unconventional secretion of pollen tube proteins and reveals likely regulators of conventional pollen tube protein secretion. The association of pollen tube-secreted proteins with marker proteins shown to be secreted via exosomes in other species suggests exosome secretion is a possible mechanism for cell–cell communication between the pollen tube and female reproductive cells. The online version of this article (doi:10.1186/s13059-016-0928-x) contains supplementary material, which is available to authorized users.