Henan Key Laboratory of Tea Plant Biology, Xinyang Normal University, Xinyang, Henan, China.
College of Life Science, Xinyang Normal University, Xinyang, Henan, China.
Plant Mol Biol. 2019 Jun;100(3):265-283. doi: 10.1007/s11103-019-00857-3. Epub 2019 Apr 15.
Symbiotic nitrogen fixation in root nodules of grain legumes is essential for high yielding. Protein phosphorylation/dephosphorylation plays important role in root nodule development. Differences in the phosphoproteomes may either be developmental specific and related to nitrogen fixation activity. An iTRAQ-based quantitative phosphoproteomic analyses during nodule development enables identification of specific phosphorylation signaling in the Lotus-rhizobia symbiosis. During evolution, legumes (Fabaceae) have evolved a symbiotic relationship with rhizobia, which fix atmospheric nitrogen and produce ammonia that host plants can then absorb. Root nodule development depends on the activation of protein phosphorylation-mediated signal transduction cascades. To investigate possible molecular mechanisms of protein modulation during nodule development, we used iTRAQ-based quantitative proteomic analyses to identify root phosphoproteins during rhizobial colonization and infection of Lotus japonicus. 1154 phosphoproteins with 2957 high-confidence phosphorylation sites were identified. Gene ontology enrichment analysis of functional groups of these genes revealed that the biological processes mediated by these proteins included cellular processes, signal transduction, and transporter activity. Quantitative data highlighted the dynamics of protein phosphorylation during nodule development and, based on regulatory trends, seven groups were identified. RNA splicing and brassinosteroid (BR) signaling pathways were extensively affected by phosphorylation, and most Ser/Arg-rich (SR) proteins were multiply phosphorylated. In addition, many proposed kinase-substrate pairs were predicted, and in these MAPK6 substrates were found to be highly enriched. This study offers insights into the regulatory processes underlying nodule development, provides an accessible resource cataloging the phosphorylation status of thousands of Lotus proteins during nodule development, and develops our understanding of post-translational regulatory mechanisms in the Lotus-rhizobia symbiosis.
共生固氮在豆科作物根瘤中对于高产至关重要。蛋白质磷酸化/去磷酸化在根瘤发育中起着重要作用。磷酸化组的差异可能是发育特异性的，与固氮活性有关。在根瘤发育过程中基于 iTRAQ 的定量磷酸蛋白质组学分析可识别特定的磷酸化信号在百脉根-根瘤菌共生中。在进化过程中，豆科植物（豆科）与根瘤菌形成共生关系，根瘤菌固定大气中的氮并产生氨，宿主植物可以吸收。根瘤发育取决于蛋白磷酸化介导的信号转导级联的激活。为了研究蛋白修饰在根瘤发育过程中的可能分子机制，我们使用 iTRAQ 基于定量蛋白质组学分析来鉴定百脉根根瘤菌定植和感染过程中的根磷蛋白。鉴定出 1154 个具有 2957 个高置信度磷酸化位点的磷酸蛋白。这些基因的功能组的 GO 富集分析表明，这些蛋白质介导的生物学过程包括细胞过程、信号转导和转运活性。定量数据突出了蛋白磷酸化在根瘤发育过程中的动态变化，并基于调控趋势，确定了 7 个组。RNA 剪接和油菜素内酯（BR）信号通路受到广泛的磷酸化调控，并且大多数 Ser/Arg-rich（SR）蛋白被多次磷酸化。此外，预测了许多拟议的激酶-底物对，并且在这些 MAPK6 底物中发现高度富集。本研究深入了解了根瘤发育的调控过程，提供了一个可访问的资源，用于编目在根瘤发育过程中数千个百脉根蛋白的磷酸化状态，并加深了对百脉根-根瘤菌共生中翻译后调控机制的理解。
