Unidirectional movement of small RNAs from shoots to roots in interspecific heterografts

第一作者：Shuai Li

第一单位：普渡大学

通讯作者：Jianxin Ma

 Abstract 

背景+问题：Long-distance RNA movement is important for plant growth and environmental responses; however, the extent to which RNAs move between distant tissues, their relative magnitude and functional importance remain to be elucidated on a genomic scale.

主要发现：Using a soybean (Glycine max)–common bean (Phaseolus vulgaris) grafting system, we identified 100 shoot–root mobile microRNAs and 32 shoot–root mobile phased secondary small interfering RNAs (phasiRNAs), which were predominantly produced in shoots and transported to roots, and, in most cases, accumulated to a level similar to that observed in shoots.

结果1-miRNA&phasiRNAs：Many of these microRNAs or phasiRNAs enabled cleavage of their messenger RNA targets or phasiRNA precursors in roots.

结果2-mRNA：In contrast, most mobile-capable mRNAs were transcribed in both shoots and roots, with only small proportions transported to recipient tissues.

结论：These findings suggest that the regulatory mechanisms for small RNA movement are different from those for mRNA movement, and that the former is more strictly regulated and, probably, more functionally important than the latter.

 摘 要 

长距离RNA移动对于植物生长和环境响应是非常重要的；但是，具体的哪些RNAs会在相距甚远的组织之间迁移，以及其相对量级和功能重要性仍然缺少基因组层面的诠释。本文中，作者利用大豆Glycine max和菜豆Phaseolus vulgaris之间的嫁接系统，鉴定了100个shoot-root的移动microRNAs和32个shoot-root的移动phasiRNAs，这些RNAs主要在shoot中产生，然后转运到root，并且在root中积累的量与shoot中相似。这些移动的microRNAs或者phasiRNAs中，大多可以在根中剪切其mRNA靶标或者phasiRNA前体。相反，大多数可移动的mRNAs在shoot和root中均可转录，仅有一小部分会被运送到受体组织。本文的发现揭示了小RNA移动的机制与mRNA移动机制不同，并且相比于mRNA移动，小RNA的移动收到更加严格的调控，因此在功能上可能要比mRNA移动更加重要。

 通讯作者 

**Jianxin Ma**

doi: https://doi.org/10.1038/s41477-020-00829-2

Journal: Nature Plants

Published date: Jan 15, 2021