Triarabinosylation is required for nodulation-suppressive CLE peptides to systemically inhibit nodulation in Pisum sativum
Triarabinosylation is required for nodulation-suppressive CLE peptides to systemically inhibit nodulation in Pisum sativum
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DOI：
10.1111/pce.13325
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发表时间：
2019-01-01
影响因子：
7.3
通讯作者：
Ferguson, Brett J.
中科院分区：
文献类型：
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作者：
Hastwell, April H.;Corcilius, Leo;Ferguson, Brett J.
豆类形成根瘤，容纳有益的固氮根瘤菌。然而，结瘤是需要资源的；因此，豆科植物进化出一种称为结瘤自动调节(AON)的系统信号机制来控制结瘤数量。怡安从在根中产生CLE多肽开始，这些多肽被预测为糖基化，运输到地上部，并被感知。我们合成了抑制结瘤的CLE多肽的变异体，通过叶柄喂食将CLE多肽引入到芽中来测试它们的活性。化学合成了大豆GmRIC1a和GmRIC2a的羟基化、单阿拉伯糖基化和三阿拉伯糖基化突变体，并将其饲喂到受体豌豆植株中，因为大豆中没有关键的Aon途径突变体。三阿拉伯糖基化的GmRIC1a和GmRIC2a抑制了野生型豌豆的结瘤，而其他被测试的多肽变体都没有这种能力。超结瘤受体突变体Pssym29和一定程度上的Pssym28对超结瘤受体突变体Psnod3也有抑制作用。在我们的研究中，豌豆的生物信息资源变得可用，我们的分析确定了40个CLE多肽编码基因，包括抑制结瘤的CLE多肽的同源基因。总之，我们证明了抑制大豆结瘤的CLE多肽可以在豌豆的Aon途径中发挥特异功能，并且需要阿拉伯糖基化才能发挥它们的活性。
Legumes form root nodules to house beneficial nitrogen-fixing rhizobia bacteria. However, nodulation is resource demanding; hence, legumes evolved a systemic signalling mechanism called autoregulation of nodulation (AON) to control nodule numbers. AON begins with the production of CLE peptides in the root, which are predicted to be glycosylated, transported to the shoot, and perceived. We synthesized variants of nodulation-suppressing CLE peptides to test their activity using petiole feeding to introduce CLE peptides into the shoot. Hydroxylated, monoarabinosylated, and triarabinosylated variants of soybean GmRIC1a and GmRIC2a were chemically synthesized and fed into recipient Pisum sativum (pea) plants, which were used due to the availability of key AON pathway mutants unavailable in soybean. Triarabinosylated GmRIC1a and GmRIC2a suppressed nodulation of wild-type pea, whereas no other peptide variant tested had this ability. Suppression also occurred in the supernodulating hydroxyproline O-arabinosyltransferase mutant, Psnod3, but not in the supernodulating receptor mutants, Pssym29, and to some extent, Pssym28. During our study, bioinformatic resources for pea became available and our analyses identified 40 CLE peptide-encoding genes, including orthologues of nodulation-suppressive CLE peptides. Collectively, we demonstrated that soybean nodulation-suppressive CLE peptides can function interspecifically in the AON pathway of pea and require arabinosylation for their activity.