Institute of Biotechnology, National Taiwan University, No.1, Sec. 4, Roosevelt Rd., Taipei 106319, Taiwan, R.O.C.
Institute of Plant Biology, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd., Taipei 106319, Taiwan, R.O.C.
Plant Cell Physiol. 2024 Jul 30;65(7):1115-1134. doi: 10.1093/pcp/pcae029.
The miR390-derived TAS3 trans-acting short-interfering RNAs (tasiRNAs) module represents a conserved RNA silencing pathway in the plant kingdom; however, its characterization in the bryophyte Marchantia polymorpha is limited. This study elucidated that MpDCL4 processes MpTAS3 double-stranded RNA (dsRNA) to generate tasiRNAs, primarily from the 5'- and 3'-ends of dsRNA. Notably, we discovered a novel tasiRNA, tasi78A, which can negatively regulate a cytochrome P450 gene, MpCYP78A101. Additionally, tasi78A was abundant in MpAGO1, and transient expression assays underscored the role of tasi78A in repressing MpCYP78A101. A microRNA, miR11700, also regulates MpCYP78A101 expression. This coordinate regulation suggests a role in modulating auxin signaling at apical notches of gemma, influencing the growth and sexual organ development of M. polymorpha and emphasizing the significance of RNA silencing in MpCYP78A101 regulation. However, phylogenetic analysis identified another paralog of the CYP78 family, Mp1g14150, which may have a redundant role with MpCYP78A101, explaining the absence of noticeable morphological changes in loss-of-function plants. Taken together, our findings provide new insights into the combined regulatory roles of miR390/MpTAS3/miR11700 in controlling MpCYP78A101 and expand our knowledge about the biogenesis and regulation of tasiRNAs in M. polymorpha.
miR390 衍生的 TAS3 反式作用小干扰 RNA（tasiRNA）模块代表了植物王国中一种保守的 RNA 沉默途径；然而，其在苔藓植物 Marchantia polymorpha 中的特征描述有限。本研究阐明了 MpDCL4 加工 MpTAS3 双链 RNA（dsRNA）以产生 tasiRNA，主要来自 dsRNA 的 5'和 3'端。值得注意的是，我们发现了一种新的 tasiRNA，tasi78A，可以负调控细胞色素 P450 基因 MpCYP78A101。此外，tasi78A 在 MpAGO1 中丰富，瞬时表达实验强调了 tasi78A 在抑制 MpCYP78A101 中的作用。一种 microRNA，miR11700，也调节 MpCYP78A101 的表达。这种协调调控表明其在调节顶端叶芽中的生长素信号方面发挥作用，影响 M. polymorpha 的生长和性器官发育，并强调了 RNA 沉默在 MpCYP78A101 调控中的重要性。然而，系统发育分析鉴定了 CYP78 家族的另一个 paralog，Mp1g14150，它可能与 MpCYP78A101 具有冗余作用，解释了功能丧失植物中没有明显形态变化的原因。总之，我们的发现为 miR390/MpTAS3/miR11700 联合调控 MpCYP78A101 提供了新的见解，并扩展了我们对 M. polymorpha 中 tasiRNA 生物发生和调控的认识。
