Genome-Wide Medicago truncatula Small RNA Analysis Revealed Novel MicroRNAs and Isoforms Differentially Regulated in Roots and Nodules
Genome-Wide Medicago truncatula Small RNA Analysis Revealed Novel MicroRNAs and Isoforms Differentially Regulated in Roots and Nodules
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DOI：
10.1105/tpc.109.068130
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发表时间：
2009-09-01
期刊：
影响因子：
11.6
通讯作者：
Crespi, Martin
中科院分区：
文献类型：
--
作者：
Lelandais-Briere, Christine;Naya, Loreto;Crespi, Martin
由21- 24个核苷酸的小RNA，特别是microRNA（miRNAs）对各种mRNA的转录后调节正在成为一种新的发育机制。在豆科植物中，如模式蒺藜苜蓿，根能够通过与固氮根瘤菌的共生相互作用而重新形成分生组织。我们使用了来自M根尖和结节的小RNA的深度测序。truncatula鉴定了100个新的候选miRNAs，它们由265个发夹前体编码。新的非典型前体类只产生特定的21-和24-核苷酸的small RNAs. Statistical分析测序读数丰度揭示特定的miRNA异构体在同一个家庭之间的差异表现出根瘤和根尖的表达模式。差异表达的保守和非保守miRNAs可能靶向多种mRNAs。在根瘤中，这表明从持久的分生组织到完全分化的中心区域的不同细胞类型，我们发现miRNA在空间上富集在根瘤分生组织，维管束和细菌感染区使用原位杂交。miRNA的空间调控可能决定植物分化过程中调控RNA网络的特化，如根瘤形成。
Posttranscriptional regulation of a variety of mRNAs by small 21- to 24-nucleotide RNAs, notably the microRNAs (miRNAs), is emerging as a novel developmental mechanism. In legumes like the model Medicago truncatula, roots are able to develop a de novo meristem through the symbiotic interaction with nitrogen-fixing rhizobia. We used deep sequencing of small RNAs from root apexes and nodules of M. truncatula to identify 100 novel candidate miRNAs encoded by 265 hairpin precursors. New atypical precursor classes producing only specific 21- and 24-nucleotide small RNAs were found. Statistical analysis on sequencing reads abundance revealed specific miRNA isoforms in a same family showing contrasting expression patterns between nodules and root apexes. The differentially expressed conserved and nonconserved miRNAs may target a large variety of mRNAs. In root nodules, which show diverse cell types ranging from a persistent meristem to a fully differentiated central region, we discovered miRNAs spatially enriched in nodule meristematic tissues, vascular bundles, and bacterial infection zones using in situ hybridization. Spatial regulation of miRNAs may determine specialization of regulatory RNA networks in plant differentiation processes, such as root nodule formation.