Liu Chunhao, Li An, Guo Zhonglong, Chen Ningcong, Wang Yin, Tang Wenxiong, Wu Yuexin, Liu Jingyi, Wang Zihao, Li Lei, He Xin-Qiang
State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China.
BOE Technology Group Co., Ltd., Beijing 100176, China.
Plant Cell. 2024 Dec 23;37(1). doi: 10.1093/plcell/koaf011.
Tracheary elements (TEs) are vital in the transport of various substances and contribute to plant growth. The differentiation of TEs is complex and regulated by a variety of microRNAs (miRNAs). However, the dynamic changes in miRNAs during each stage of TE differentiation remain unclear, and the miRNA regulatory network is not yet complete. This study employed Vascular cell Induction culture System Using Arabidopsis Leaves to profile the miRNome during TE differentiation in Arabidopsis (Arabidopsis thaliana) and established comprehensive miRNA co-expression networks functioning at the different stages of TE differentiation. Two negatively correlated modules exist in the miRNA networks, each exhibiting strong intra-module positive correlation and strong inter-module negative correlation. Thus, the 2 modules may play opposite roles in TE differentiation and vascular development. Indeed, we found that miR408 promotes cambium formation and TE differentiation, consistent with miR408 as a key node in the networks of fate determination and the initiation of TE differentiation. Additionally, we found that miR163 inhibits secondary cell wall formation and TE differentiation, corresponding to miR163 as a key node in the TE maturation network. Moreover, we discovered that the miRNA co-expression network in poplar (Populus tomentosa) xylem development is also composed of 2 negatively correlated modules that contain miRNAs orthologous to those in Arabidopsis. Therefore, the 2 negatively correlated modules of the miRNA co-expression network are likely conserved and fundamental to xylem TE differentiation. These results provide insights into microRNA regulation in plant development.
管状分子（TEs）在各种物质的运输中起着至关重要的作用，并对植物生长有贡献。TEs的分化过程复杂，受多种微小RNA（miRNAs）调控。然而，TEs分化各阶段中miRNAs的动态变化仍不清楚，且miRNA调控网络尚不完整。本研究利用拟南芥叶片的维管细胞诱导培养系统，对拟南芥（Arabidopsis thaliana）TEs分化过程中的miRNA组进行了分析，并建立了在TEs分化不同阶段发挥作用的综合miRNA共表达网络。miRNA网络中存在两个负相关模块，每个模块内部呈现出强烈的正相关，而模块间呈现出强烈的负相关。因此，这两个模块可能在TEs分化和维管发育中发挥相反的作用。事实上，我们发现miR408促进形成层的形成和TEs分化，这与miR408作为命运决定和TEs分化起始网络中的关键节点相一致。此外，我们发现miR163抑制次生细胞壁的形成和TEs分化，这与miR163作为TEs成熟网络中的关键节点相对应。而且，我们发现毛白杨（Populus tomentosa）木质部发育中的miRNA共表达网络也由两个负相关模块组成，其中包含与拟南芥中同源的miRNAs。因此，miRNA共表达网络的这两个负相关模块可能是保守的，并且对木质部TEs分化至关重要。这些结果为植物发育中的微小RNA调控提供了见解。
