植物环状RNA的研究新进展

doi:10.13560/j.cnki.biotech.bull.1985.2021-1586

摘要/Abstract

摘要：

环状RNA（circRNAs）是一类由共价键连接形成环形结构的单链内源性RNA分子。作为非编码RNA家族中重要的成员之一，近年来受到广泛的关注。现有研究已证实circRNAs广泛存在于真核生物中。高通量测序技术以及生物信息学的发展，极大地加速了circRNAs研究进展。研究表明，circRNAs具有结构稳定、序列保守以及组织/发育特异性表达等特点。目前，研究揭示circRNAs的主要功能包括作为miRNA的海绵、参与植物应激反应、调控亲本基因表达等。本文在总结其分类和主要特征的基础上，着重阐述了植物circRNAs的生物学功能，为circRNAs的进一步研究提供参考。

关键词: circRNAs, 分子特征, 生物学功能, 植物

Abstract:

Circular RNAs（circRNAs）are covalently closed-loop single-stranded RNA molecules. As an important member of the endogenous noncoding family，circRNA has received more and more attention in recent years. circRNAs widely exist in higher eukaryotes. The studies of circRNAs have been accelerated by the combination of next generation sequencing，chemoinformatics and some other advanced technologies. Studies have shown that circRNAs are relatively stable and conserved molecules with cell-type-，tissue-，or developmental-stage-specific expression patterns. Until now，the functions of circRNAs include acting as miRNA sponges，coping with biotic or abiotic stresses and regulating parental gene transcription，etc. Here，we summarize the classification and characteristics of plant circRNAs，and highlight the progress on their biological functions and their applications as biomarkers in plant breeding and improvement of stress resistance. This article will provide a reference for the further study of circRNAs.

Key words: circRNAs, molecular characteristics, biological functions, plants

赵杰, 李安, 梁刚, 靳欣欣, 潘立刚. 植物环状RNA的研究新进展[J]. 生物技术通报, 2022, 38(10): 1-9.

ZHAO Jie, LI An, LIANG Gang, JIN Xin-xin, PAN Li-gang. Research Progress in the Biological Functions of Plant circRNAs[J]. Biotechnology Bulletin, 2022, 38(10): 1-9.

图/表 5

表1 不同植物组织中已鉴定出的circRNAs数量统计（2017-2021）

Table 1 Statistics of identified circRNAs in different plant tissues（2017-2021）

植物Plants	测序样本Sequencing samples	circRNA数量Number of circRNAs	参考文献Reference
拟南芥 Arabidopsis thaliana	种子 Seed	30 923	[11]
番茄 Solanum lycopersicum L.	果实 Fruit	3 796	[12]
大豆 Glycine max	叶/根/茎 Leaf/root/stem	5 372	[13]
水稻 Oryza sativa L.	叶片 Leaf	6 612	[14]
玉米 Zea mays	茎 Stem	1 199	[15]
小麦 Triticum aestivum L.	根 Root	285-478	[16]
马铃薯 Solanum tuberosum L.	茎 Stem	2 098	[17]
葡萄 Vitis vinifera L.	根/茎/叶/花/果实 Root/stem/leaf/flower/berry	1 432	[18]
沙棘 Hippophae rhamnoides L.	果实 Fruit	2 616	[19]
杜梨 Pyrus betulifolia	叶片 Leaf	899	[20]
猕猴桃 Actinidia	叶/根/茎 Leaf/root/stem	3 582	[21]
茶叶 Camellia sinensis	叶芽/幼叶 Leaf bud/young leaf	3 174	[22]

图1 circRNAs的分类 A：来源于外显子、外显子-内含子的circRNA；B：来源于内含子的circRNA；C：来源于转运RNA内含子的circRNA[23]。A、B中不同颜色的矩形表示外显子，绿色直线表示内含子，蓝色箭头表示规范剪接形成了线性mRNA，红色箭头表示非规范剪切，即形成了环状RNA

Fig.1 Classification of circular RNAs A：circRNA from exonic and exon-intron RNAs；B：circRNA from intron RNAs；C：circRNA from tRNA introns[23]. In A and B，rectangles in different colors represent exons，green straight lines represent introns，the blue arrows indicate that the canonical splicing produces linear mRNAs，the red arrows represent noncanonical splicing（back-splicing），i.e.，circRNA is formed

图2 circRNA的功能在细胞核中富集的EIciRNAs和ciRNAs通过与RNA聚合酶Pol II相互作用调控基因转录，ecircRNAs通常在胞质中，作为miRNA海绵、RBP海绵和传递中间体起作用[23]。图中不同颜色的矩形表示外显子，绿色直线表示内含子，红色箭头表示由非规范剪切形成了环状RNA

Fig.2 circRNA functions EIciRNAs and ciRNAs enriched in nucleus may regulate gene transcription through interaction with Pol II，ecircRNAs act as miRNA sponges，RBP sponges and delivery intermediates in cytoplasmic[23]. Rectangles in different colors represent exons，green straight lines represent introns，and the red arrows represent noncanonical splicing（back-splicing）and circRNAs are formed

图3 大豆circRNAs-gma_circ_0000569及gma_circ_0000741在冷胁迫下的调节网络

Fig. 3 Regulation network of circRNAs-gma_circ_0000569 and gma_circ_0000741 of soybean under cold stress

表2 circRNAs在植物应激反应中的研究（2017-2020）

Table 2 Studies on plant circRNAs in responding to biotic or abiotic stresses（2017-2020）

植物 Plants	应激反应 Stress response	差异表达circRNAs数量 Numbers of differentially expressed circRNAs	参考文献 Reference
番茄 Solanum lycopersicum L.	黄叶卷曲病毒 TYLCV	83	[43]
猕猴桃 Actinidia	丁香假单胞菌 Canker pathogen	584	[21]
棉花 Gossypium	黄萎病 Verticillium wilt	280	[44]
大豆 Glycine max	低温 Low-temperature	13	[45]
杨树 Populus L.	低氮 Low-nitrogen	163	[46]
番茄 Solanum lycopersicum L.	干旱和高温 Drought and heat	4/7/9	[47]
大豆 Glycine max	低磷 Low-phosphorus	120	[48]
大豆 Glycine max	干旱 Drought	44	[49]
杜梨 Pyrus betulifolia	干旱Drought	33	[20]
番茄 Solanum lycopersicum L.	低温 Low-temperature	383	[50]
番茄 Solanum lycopersicum L.	高温 High-temperature	73	[51]
玉米/拟南芥 Zea mays/Arabidopsis thaliana	干旱Drought stress	357/446	[52]

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