Characterization of the Spatial and Temporal Expression of Two Soybean miRNAs Identifies SCL6 as a Novel Regulator of Soybean Nodulation
Characterization of the Spatial and Temporal Expression of Two Soybean miRNAs Identifies SCL6 as a Novel Regulator of Soybean Nodulation
复制标题
DOI：
10.3389/fpls.2019.00475
复制
发表时间：
2019-04-16
影响因子：
5.6
通讯作者：
Stacey, Gary
中科院分区：
文献类型：
--
作者：
Hossain, Md Shakhawat;Hoang, Nhung T.;Stacey, Gary
MicroRNA (miRNA) 通过转录本切割或翻译抑制来控制内源靶基因的表达。豆科植物可以通过与固氮土壤细菌的相互作用形成一种特殊的器官，即根瘤。为了了解 miRNA 在结瘤过程中的调节作用，我们对大豆中的 gma-miR171o 和 gma-miR171q 及其靶基因进行了功能验证。这两个 miRNA 序列在序列上是相同的，但它们的 miRNA 基因是不同的，并且表现出独特的、组织特异性的表达模式。两个miRNA的表达水平与其靶基因的表达水平呈负相关。这些 miRNA 在转基因毛状根中的异位表达导致根瘤形成显着减少。 gma-miR171o 和 gma-miR171q 均靶向 GRAS 转录因子超家族的成员，即 GmSCL-6 和 GmNSP2。烟草细胞中 miRNA 与其靶基因的瞬时相互作用进一步证实了它们的裂解活性。结果表明，gma-miR171o和gma-miR171q调节GmSCL-6和GmNSP2，进而影响慢生根瘤菌-大豆结瘤过程中根瘤起始（NIN）、早期结瘤蛋白40（ENOD40）和结瘤所需乙烯反应因子（ERN）基因的表达。总的来说，我们的数据表明两种 miRNA（gma-miR171o 和 gma-miR171q）在调节大豆结瘤的空间和时间方面的作用。
MicroRNAs (miRNAs) control expression of endogenous target genes through transcript cleavage or translational inhibition. Legume plants can form a specialized organ, the nodule, through interaction with nitrogen fixing soil bacteria. To understand the regulatory roles of miRNAs in the nodulation process, we functionally validated gma-miR171o and gma-miR171q and their target genes in soybean. These two miRNA sequences are identical in sequence but their miRNA genes are divergent and show unique, tissue-specific expression patterns. The expression levels of the two miRNAs are negatively correlated with that of their target genes. Ectopic expression of these miRNAs in transgenic hairy roots resulted in a significant reduction in nodule formation. Both gma-miR171o and gma-miR171q target members of the GRAS transcription factor superfamily, namely GmSCL-6 and GmNSP2. Transient interaction of miRNAs and their target genes in tobacco cells further confirmed their cleavage activity. The results suggest that gma-miR171o and gma-miR171q regulate GmSCL-6 and GmNSP2, which in turn, influence expression of the Nodule inception (NIN), Early Nodulin 40 (ENOD40), and Ethylene Response Factor Required for Nodulation (ERN) genes during the Bradyrhizobium japonicum-soybean nodulation process. Collectively, our data suggest a role for two miRNAs, gma-miR171o and gma-miR171q, in regulating the spatial and temporal aspects of soybean nodulation.