m5C Methylation Guides Systemic Transport of Messenger RNA over Graft Junctions in Plants

First author: Lei Yang; Affiliations: Max-Planck-Institute of Molecular Plant Physiology (马普分子植物生理研究所学): Golm, Germany

Corresponding author: Friedrich Kragler

In plants, transcripts move to distant body parts to potentially act as systemic signals regulating development and growth. Thousands of messenger RNAs (mRNAs) are transported across graft junctions via the phloem to distinct plant parts. Little is known regarding features, structural motifs, and potential base modifications of transported transcripts and how these may affect their mobility. We identified Arabidopsis thaliana mRNAs harboring the modified base 5-methylcytosine (m5C) and found that these are significantly enriched in mRNAs previously described as mobile, moving over graft junctions to distinct plant parts. We confirm this finding with graft-mobile methylated mRNAs TRANSLATIONALLY CONTROLLED TUMOR PROTEIN 1 (TCTP1) and HEAT SHOCK COGNATE PROTEIN 70.1 (HSC70.1), whose mRNA transport is diminished in mutants deficient in m5C mRNA methylation. Together, our results point toward an essential role of cytosine methylation in systemic mRNA mobility in plants and that TCTP1 mRNA mobility is required for its signaling function.

在植物中，转录本有时会从产生部位移动到距离较远的组织器官中，作为系统信号调控生长发育。数千个信使RNA会通过韧皮部越过嫁接位点，转运到距离较远的组织部位中发挥功能。但关于该过程的了解不多，包括结构基序、被转运的转录本上潜在的碱基修饰以及这些特性如何影响这些转录本的移动。作者在本文中鉴定了拟南芥中具有m5C修饰剪辑的mRNA，并且发现这些mRNA显著富集之前鉴定为可移动、并且能够跨越嫁接位点到距离较远组织部位的转录本。另外，作者发现在mRNA m5C甲基化缺陷的突变体中，嫁接移动、被甲基化的TCTP1和HSC70.1基因的转录本消失。综上，本文的研究揭示了植物中胞嘧啶甲基化在系统性mRNA移动中的作用，并且表明TCTP1基因mRNA的移动对于其信号转导功能的实现是必需的。

通讯：Friedrich Kragler (https://www.mpimp-golm.mpg.de/9327/Friedrich_Kragler)

个人简介：1991年， 维也纳大学，学士；1995年，维也纳大学，博士。

研究方向：植物韧皮部介导的大分子转运。

doi: https://doi.org/10.1016/j.cub.2019.06.042

Journal: Current Biology

Published date: July 18, 2019