The protein modifications of O-GlcNAcylation and phosphorylation mediate vernalization response for flowering in winter wheat

作  者:Xu SJ, Xiao J, Yin F, Guo XY, Xing LJ, Xu YY, Chong K*
影响因子:5.949
刊物名称:Plant Physiology
出版年份:2019
卷:  期:  页码:DOI: 10.1104/pp.19.00081

论文摘要:

O-GlcNAcylation and phosphorylation are two post-translational modifications that antagonistically regulate protein function. However, the regulation of and the crosstalk between these two protein modifications are poorly understood in plants. Here we investigated the role of O-GlcNAcylation during vernalization, a process whereby prolonged cold exposure promotes flowering in winter wheat (Triticum aestivum), and analyzed the dynamic profile of O-GlcNAcylated and phosphorylated proteins in response to vernalization. Altering O-GlcNAc signaling by chemical inhibitors affected the vernalization response, modifying the expression of VRN genes and subsequently affecting flowering transition. Over a vernalization time-course, O-GlcNAcylated and phosphorylated peptides were enriched from winter wheat plumules by Lectin weak affinity chromatography (LWAC) and iTRAQ-TiO2, respectively. Subsequent mass spectrometry and GO term enrichment analysis identified 168 O-GlcNAcylated proteins that are mainly involved in responses to abiotic stimulus and hormones, metabolic processing and gene expression; and 124 differentially expressed phosphorylated proteins that participate in translation, transcription and metabolic processing. Of note, 31 vernalization-associated proteins were identified that carried both phosphorylation and O-GlcNAcylation modifications, of which the majority (97%) exhibited the coexisting module and the remainder exhibited the potential competitive module. Among these, TaGRP2 was decorated with dynamic O-GlcNAcylation (S87) and phosphorylation (S152) modifications, and the mutation of S87 and S152 affected the binding of TaGRP2 to the RIP3 motif of TaVRN1 in vitro. Our data suggest that a dynamic network of O-GlcNAcylation and phosphorylation at key pathway nodes regulate the vernalization response and mediate flowering in wheat.

全文链接:http://www.plantphysiol.org/content/early/2019/05/06/pp.19.00081