Max-Planck-Institute of Molecular Plant Physiology, Wissenschaftspark Golm, Am Mühlenberg 1, 14476 Golm, Germany.
Institut de Biologie de l'Ecole Normale Supérieure (IBENS), CNRS UMR8197, INSERM U1024, PSL Research University, 75230 Paris, France.
Curr Biol. 2019 Aug 5;29(15):2465-2476.e5. doi: 10.1016/j.cub.2019.06.042. Epub 2019 Jul 18.
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 (mC) 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 mC 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，转录物移动到遥远的身体部位，可能作为调节发育和生长的系统信号。数千种信使 RNA（mRNA）通过韧皮部运输到嫁接交界处的不同植物部位。关于运输转录物的特征、结构基序和潜在的碱基修饰以及这些修饰如何影响它们的移动性，我们知之甚少。我们鉴定了拟南芥中含有修饰碱基 5-甲基胞嘧啶（mC）的 mRNA，并发现这些 mRNA 在前文中被描述为可移动的，能够通过嫁接交界处移动到不同的植物部位，其丰度显著增加。我们通过嫁接移动的甲基化 mRNA 翻译控制肿瘤蛋白 1（TCTP1）和热休克同源蛋白 70.1（HSC70.1）证实了这一发现，它们的 mRNA 运输在 mC mRNA 甲基化缺陷突变体中减少。总之，我们的研究结果表明，胞嘧啶甲基化在植物中系统性 mRNA 移动性中具有重要作用，并且 TCTP1 mRNA 的移动性是其信号功能所必需的。
